Chevrolet Light Duty Truck 1973 Service Manual

Chevrolet 1973 light duty truck service manual

page of 979

/ 979
Contents
Table of Contents
Bookmarks

Table of Contents

Quick Links

Download this manual

Table of Contents

Chapters

Table of Contents

Summary of Contents for Chevrolet Light Duty Truck 1973

Page 2 Chevrolet Light Duty Trucks. Procedures involving dis assembly and assembly of major components for these vehicles are contained in the 1973 Chevrolet Passenger Car and Light Duty Truck Overhaul Manual. Wiring diagrams for 1973 trucks are contained in a separate Wiring Diagram Booklet.
Page 3 IMPORTANT SAFETY NOTICE Proper service and repair is important to the safe, reliable operation of all motor vehicles. The service procedures recommended and described in this service manual are effective methods, for performing service operations. Some of these service operations require the use of tools specially designed for the purpose.
Page 5 S E C T I O N I N D E X SECTION NAME GENERAL INFORMATION AND LUBRICATION HEATER AND AIR CONDITIONING BODY FRAME FRONT SUSPENSION 4-WHEEL DRIVE REAR SUSPENSION 1973 AND DRIVELINE BRAKES LIGHT DUTY ENGINE ENGINE COOLING TRUCK FUEL SYSTEM EMISSION CONTROL (SERIES 10-30)
Page 7 GENERAL IN F O R M A T IO N A N D L UBRICATION SECTION 0 GENERAL INFORMATION AND LUBRICATION CONTENTS OF THIS SECTION General Inform ation................ 0-1 Lubrication................... 0-12 GENERAL INFO RM ATIO N INDEX Model Line U p ..............0-1 Service Parts Identification Plate ....
Page 8 Y = V8 DIVISION would breakdown thus: Z — V8 MODEL YEAR C = CHEVROLET F - M anufacturing Plant (F-Flint, T-Tonawanda) 3 = 1973 fo r all T = G M T Series. 12 - Month of Manufacture (December)
Page 9 GENERAL IN F O R M A T IO N AND LUBRICATION discharged batteries. Lay a cloth over the open vent S E R V I C E P A R TS I D E N T I F I C A T I O N ____________ wells of each battery.
Page 10 0 -4 GENERAL IN F O R M A T IO N A N D LUBRICATIO N should not exceed 35 MPH for distances up to 50 miles. PUSH STARTING If truck is towed on its front wheels, the steering wheel should be secured to keep the front wheels in a straight...
Page 11 GENERAL IN F O R M A T IO N A ND LUBR IC A TION In trailer hauling applications, the vehicle rear end weight at the ground with trailer attached must not LOADED-MAXIMUM GVW: 6000-LBS- exceed the "Maximum Rear End Weight at Ground" rating of the vehicle.
Page 12 0 6 GENERAL IN F O R M A T IO N A N D LUBRICATIO N LOAD CAPACITY CHART M I N I M U M M A N D A T O R Y E Q U I P M E N T F O R G V W R A T I N G G R O S S G R O S S G R O S S...
Page 13 GENERAL IN F O R M A T IO N A N D LUBRICATION LOAD CAPACITY CHART M I N I M U M M A N D A T O R Y E Q U I P M E N T F O R G V W R A T I N G G R O S S G R O S S G R O S S...
Page 14 — tf-8 GENERAL IN F O R M A T IO N A N D LU BR IC A TIO N LOAD CAPACITY CHART M I N I M U M M A N D A T O R Y E Q U I P M E N T F O R G V W R A T I N G G R O S S G R O S S G R O S S...
Page 15 GENERAL IN F O R M A T IO N A N D LUBRICATION 0 -9 LOAD CAPACITY CHART M I N I M U M M A N D A T O R Y E Q U I P M E N T F O R G VW R A T I N G G R O S S G R OS S G R O S S...
Page 16 0 - 1 0 GENERAL IN F O R M A T IO N A N D LUBRIC ATIO N LOAD CAPACITY CHART M I N I M U M M A N D A T O R Y E Q U I P M E N T F O R G V W R A T I N G G R O S S G R O S S G R O S S...
Page 17 GENERAL IN F O R M A T IO N A N D LUBR IC A TION 0-11 LO A D C A P A C ITY C H A R T M I N I M U M M A N D A T O R Y E Q U I P M E N T F O R G VW R A T I N G G R OS S GR OS S G R O S S 1...
Page 18 0 -1 2 GENERAL IN F O R M A T IO N A N D LUBRIC ATIO N LUBRICATION INDEX Wheel Bearings Maintenance Schedule............0-12 E ngine..................0-12 Front..................0-15 R ear..................0-15 Oil and Filter Recommendations........ 0-12 Brake Master Cylinder............0-15 Drive Belts................
Page 19 GENERAL IN F O R M A T IO N AND LU BRICATION 0 -1 3 longer than those listed above will seriously reduce mark on the dipstick, oil should be added as necessary. engine life and may affect the m anufacturer’s The oil level should be maintained in the safety margin, obligation under the provisions of the New Vehicle neither going above the "FU LL"...
Page 20 0 - 1 4 GENERAL IN F O R M A T IO N A N D LUBRICATIO N 1. Drive vehicle several miles, making frequent starts AIR CLEANER and stops, to bring transmission up to normal Do not remove the engine air operating temperature (approximately 180-190°F).
Page 21 GENERAL IN F O R M A T IO N A ND L UBRICATION 0 -1 5 The bearings should be thoroughly cleaned before REAR AXLES repacking with lubricant. Standard Front wheels are equipped with tapered roller bearings Every 4 months or 6,000 miles, whichever occurs first, on all trucks.
Page 22 0 - 1 6 GENERAL IN F O R M A T IO N A N D LUBRICATIO N 2. Apply Lubriplate or equivalent to latch pilot bolt automatic Transmission Fluid or equivalent as DEXRON and latch locking plate. necessary to bring level into proper range on filler cap indicator depending upon fluid temperature.
Page 23 GENERAL IN F O R M A T IO N A ND LUBRIC ATIO N 0 -1 7 Conventional Four Wheel Drive Propeller Shaft Centering Ball Add SAE 80 or SAE 90 GL-5 Gear Lubricant to bring to A centering ball at the transfer case end of the front level of filler plug hole.
Page 24 0 -1 8 GENERAL IN F O R M A T IO N A N D LUBRIC ATIO N Fig. 8—Lubrication—Conventional Models Lubrication Type of Lubrication Points Quantity Remarks Period Lubrication Lower Control Arms 6,000 Miles Chassis Lubricant 4 places as required Upper Control Arms 6,000 Miles Chassis Lubricant...
Page 25 GENERAL IN F O R M A T IO N A N D LUBRICATION 0 -1 9 Fig. 9—Lubrication—Four Wheel Drive Models Lubrication Type of Quantity Remarks Lubrication Points Lubrication Period Replace L-6. Rotate V-8. A ir Cleaner 12,000 Miles Replace V-8 at 24,000 miles.
Page 26 0 -2 0 GENERAL IN F O R M A T IO N A N D LUBRIC ATIO N Fig. 10—Lubrication—1/2, 3/4 and 1 Ton G Models Lubrication Type of Lubrication Points Q uantity Remarks Period Lubrication Control Arm Bushings and Ball Joints 6,000 Miles Chassis Lubricant...
Page 27 HEATER A N D AIR C O N D IT IO N IN G 1A-1 SECTION 1A HEATER AND AIR CONDITIONING CONTENTS OF THIS SECTION Standard H eater................1A-1 Auxiliary H eater................1A-14 Air C onditioning................1A-18 STANDARD HEATER INDEX Center Distributor Duct - G M odels.....
Page 28 H EA TE R A D E F R O S T E R A S M H E A T E R A D E F R O S T E R A S M (H E AT E R IN OFF P O S I T I O N ) AIR OUTLET AI R OU T L E T VI EW A...
Page 29 HEATER A N D AIR C O N D IT IO N IN G 1A-3 THEORY OF OPERATION TURE door in the heater distributor assembly. All BLOWER AND AIR INLET ASSEMBLY incoming "outside" air is directed around the heater core The blower and air inlet assembly draws outside air in the COLD position or through the core in the HOT through the outside air inlet grille located forward of the...
Page 30 1 A-4 HEATER A N D AIR C O N D IT IO N IN G the system. Moving the lever to the right (toward Temperature Lever HEATER) opens the air door with the AIR door being This lever controls the positioning of the TEMPERA fully open at the HEATER position.
Page 31 HEATER A N D AIR C O N D IT IO N IN G 1A-5 then remove the heater case and core as an 4. Remove the glove box and door assembly. assembly. Tilt the case assembly rearward at the top 5.
Page 32 1A-6 HEATER A N D AIR C O N D IT IO N IN G Fig. 7 -Heater Hose Routings assembly (see "Heater Distributor and Core- 2. Unsnap the engine cover front latches. Remove the Replacement"). two cover to floorpan screws and remove the cover. 4.
Page 33 HEATER A N D AIR C O N D IT IO N IN G 1A-7 LEFT DISTRIBUTOR DUCT CENTER DISTRIBUTOR DUCT HEATER CORE CASE Fig. 8-Distributor Ducts-G Models 3. Remove the control to instrument panel mounting CONTROL ASSEMBLY screws and carefully lower the control far enough to gain access to the bowden cable attachments.
Page 34 1 A-8 HEATER A N D AIR C O N D IT IO N IN G C-K MODELS DEFROSTER HOSES G MODELS Fig. 9 - D e f r o s t e r O u tle ts control lever. Remove the cable attaching screw at both door and control locations.
Page 35 HEATER A ND AIR C O N D IT IO N IN G 1A-9 DEFROSTER CABLE JER CABLE AIR CABLE W ITHOUT RADIO WITH RADIO VIEW A Fig. 1 2 -Control Cable Routing-G Models 4. Disconnect the switch electrical harness. engine cover front latches.
Page 36 1A-10 HEATER A N D AIR C O N D IT IO N IN G DIAGNOSIS C A U S E A N D C O R R E C T I O N T R O U B L E S e e "...
Page 37 HEATER A N D AIR C O N D IT IO N IN G 1A-11 INSUFFICIENT HEAT DIAGNOSIS P o sitio n th e c o n tro ls so th a t the: T e m p eratu re lever is o n fu ll heat. S elector o r heater lever is on Heater.
Page 38 H E A T E R C I R C U I T D I A G N O S I S * BLOW ER M OTO R IN O P E R A T IV E (A N Y SPEED) Check fuse in fuse panel.
Page 39 HEATER A N D AIR C O N D IT IO N IN G 1A-13 Fig. 14-Heater Wiring Diagrams LIGHT DUTY TRUCK SERVICE MANUAL...
Page 40 1A-14 HEATER A ND AIR C O N D IT IO N IN G AUXILIARY HEATER INDEX General D escription..............1A-14 C ontrols................... 1A-14 Component Replacement and Repairs........1A-16 Diagnosis................... 1A-17 GENERAL DESCRIPTION An auxiliary heater is available as a dealer installed weather, "off"...
Page 41 HEATER A N D AIR C O N D IT IO N IN G 1A-15 AUXILIARY HEATER (110" W.B. WITH REAR SEATS) EXISTING HEATER CONTROL SWITCH AUXILIARY HEATER (110" W.B. WITHOUT REAR SEATS) (ALL 125" W.B. MODELS) WATER VALVE Fig. 1 6 -A u x ilia ry H e a te r In s ta lla tio n s (G M o d e ls ) IN S T A L L V A L V E W IT H A R R O W P O IN T IN G A W A Y F R O M TEE.
Page 42 1A-16 HEATER A N D AIR C O N D IT IO N IN G Fig. 19--Control and Resistor Mountings C O M P O N E N T REPLACEMENT A N D REPAIRS Since a detailed list of installation instructions is between the auxiliary heater core lines and the included with the auxiliary heater unit, replacement exhaust pipe.
Page 43 HEATER A N D AIR C O N D IT IO N IN G 1A-17 D IA G N O S IS inoperative on C-K models (equipped with Refer to the "Standard Heater" section of this manual for diagnostic information; see Electrical Diagram Overhead Air Conditioning), check that the Figure 21.
Page 44 1A-18 HEATER A ND AIR C O N D IT IO N IN G AIR CONDITIONING INDEX General Description............1A-19 Component Part Replacement—Four-Season Four-Season System (C-K M odels)......1A-19 System................1A-58 Condenser................1A-58 Floor Mounted System (G Models)......1A-19 Overhead Systems (C-K-G Models)......1A-19 Accumulator..............
Page 45 HEATER A N D AIR C O N D IT IO N IN G 1A-19 Receiver-Dehydrator............1A-76 F use..................1A-78 Diagnosis................1A-78 Sight G lass................1A-76 Refrigerant System............1A-78 Blower-Evaporator Assembly........1A-76 Compressor Diagnosis............1A-80 Blower Assembly.............1A-77 Insufficient Cooling............1A-81 Expansion Valve, Evaporator Case or Core..1A-77 Electrical System Diagnosis........
Page 46 1A-20 HEATER A N D AIR C O N D IT IO N IN G heating (above ambient temperatures) is desired, the through the evaporator core (receiving maximum vehicle heater must be used. When air conditioning is cooling) and then directed into the vehicle through desired, the heater should be completely shut off.
Page 47 HEATER A N D AIR C O N D IT IO N IN G 1A-21 Fig. 25-Quantity of Heat = B.T.U. Fig. 24--Measurement of Heat It may seem a little puzzling to talk about heat in a book on air conditioning...but, when you stop to think about it, we are handling heat exclusively.
Page 48 1A 2 2 HEATER A N D AIR C O N D IT IO N IN G has already melted aw ay-but the thermometer still reads 32°. All this time, the ice has been soaking up heat, yet it never gets any warmer no matter how much heat it draws from the stored food.
Page 49 HEATER A ND AIR C O N D IT IO N IN G 1A-23 refrigeration. But in doing so, we have learned how a non-toxic, non-inflammable, non-explosive, and non- simple icebox works. It’s because the latent heat of poisonous, however, breathing large quantities of R-12 fusion gives ice the ability to soak up quantities of heat should be avoided.
Page 50 1A-24 HEATER A ND AIR C O N D IT IO N IN G This is where pressure helps, with pressure, we can compress the vapor, thereby concentrating the heat it contains. When we concentrate heat in a vapor that way, we increase the intensity of the heat or, we increase the temperature, because temperature is merely a measure...
Page 51 HEATER AND AIR C O N D IT IO N IN G 1A-25 and, of course, the float rides up along with it. When the surface level of the refrigerant liquid reaches a desired Pressure (psi) °F Pressure (psi) °F height, the float will have risen far enough to close the 46.7 valve and stop the flow of refrigerant liquid.
Page 52 1A-26 HEATER AND AIR C O N D IT IO N IN G out of "cold" vapor even in a warm room. An ordinary control the relative humidity of the air as well as its radiator will help us get rid of heat. temperature.
Page 53 HEATER A N D AIR C O N D IT IO N IN G 1A-27 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 54 1A-28 HEATER A N D AIR C O N D IT IO N IN G though they do contain quantities of heat. Consequently, Compressor we can’t expect to remove heat from sub-freezing vapors The prime purpose of the compressor (fig. 34) is to take by "cooling"...
Page 55 HEATER A ND AIR C O N D IT IO N IN G 1A-29 3 4 35 3 6 37 38 3 9 Thrust Bearing Pulley and Bearing Assembly Rear Head Thrust Race Pulley Bearing Rear Head to Shell " O " Ring Compressor Shell Rear Discharge Valve Plate Pulley Bearing Retainer Ring...
Page 56 1A-30 HEATER A ND AIR C O N D IT IO N IN G drilled in the head between the two. The unit number is simple field gauging operations. Seats are marked with their size which corresponds to the last three digits of the stamped on a plate attached to the counterclockwise rotation head and a decal arrow indicates the direction piece part number.
Page 57 HEATER A ND AIR C O N D IT IO N IN G 1A-31 Discharge Crossover D rive Key 2 9. S h a ft Seal Seat S h a ft N u t T u b e Rear " 0 ” R ing Discharge Crossover R etain er Ring C lutch H ub R etain er...
Page 58 1A-32 HEATER A N D AIR C O N D IT IO N IN G Refrigerant Lines THRUST UNIT Special refrigerant hose lines are required to carry the refrigerant liquid and vapor between the various system CONTROLS BALL SEATS USED components.
Page 59 HEATER A N D AIR C O N D IT IO N IN G 1A-33 storage of high pressure liquid produced in the condenser, incorporates a screen sack filled with the dehydrating agent. The receiver-dehydrator, used prim arily as a liquid storage tank, also functions to trap minute quantities of moisture and foreign material which may have remained in the system after installation or service operations.
Page 60 1A-34 HEATER A N D AIR C O N D IT IO N IN G “ O ” RING INLET Fig. 39-Expansion Tube The expansion tube is located in the enlarged portion of the evaporator inlet line. Thermostatic Switch System temperature is controlled by running the compressor intermittently, automatically turning it on and off as necessary to m aintain proper temperatures.
Page 61 HEATER AND AIR C O N D IT IO N IN G 1A-35 The compressor discharge pressure switch also performs Chemical Instability and Refrigerant the function of the ambient switch as the pressure at the System Failures switch varies directly with ambient temperatures. The A sealed refrigerating system is a complex physical- compressor should run below 25°F.
Page 62 1A-36 HEATER A N D AIR C O N D IT IO N IN G uncapped even for a few minutes allows the oil to absorb increases. A 15° rise in temperature doubles the chemical moisture from the air. action. System failures can result if contaminated oil is added to While temperature alone can cause the synthetic rubber the system.
Page 63 HEATER A ND AIR C O N D IT IO N IN G 1A-37 the desiccant and cause it to powder. The powder passes many difficulties in refrigerating systems, in most through the dehydrator screen with the refrigerant liquid instances it is the presence of moisture in the system that and is carried to the expansion valve screen.
Page 64 1A-38 HEATER A N D AIR C O N D IT IO N IN G recirculation of interior air (recirc. operation) provides a That the drying agent in the receiver or accumulator is source of fast cool down of interior temperatures. Activated Silica Alumina.
Page 65 HEATER A N D AIR C O N D IT IO N IN G 1A-39 Fig. 44- Motor Home Unit Control refrigerant is circulating in the system if the front system in ON. To operate the rear overhead system, simply select the desired blower speed (LOW, MED, HI).
Page 66 1A-40 HEATER A ND AIR C O N D IT IO N IN G • Cylinders or disposable cans should never be radius of less than 10 times the diam eter of the hose. subjected to high tem perature when adding refrigerant to the system.
Page 67 HEATER A ND AIR C O N D IT IO N IN G 1A-41 resulting in im proper operating tem perature and pressures and decreased efficiency of the system. LOW PR ESSU R E HIGH PRESSURE The following general practices CONTROL ( 2) CONTROL ( l) CAUTIO N:...
Page 68 1A-42 HEATER A N D AIR C O N D IT IO N IN G direction, in inches of vacuum. This is the gauge that should always be used in checking pressures on the low pressure side of the system. When all parts of the system are functioning properly the refrigerant pressure on the low pressure side never falls below 0 pounds pressure.
Page 69 HEATER A N D AIR C O N D IT IO N IN G 1A-43 Common sense should be the governing factor in sampling hose around possible leak points in the performing any leak test, since the necessity and extent system.
Page 70 1A-44 HEATER A N D AIR C O N D IT IO N IN G to any system having a pressure higher than definite drop after a period of time. Since the indicated on refrigerant containers. compressor oil is carried throughout the entire system mixed with the refrigerant, a low refrigerant level will 6.
Page 71 HEATER A N D AIR C O N D IT IO N IN G 1A-45 Refrigerant Oil Charge Charge Four-Season System REFRIGERANT LINE 3 lbs. 10 oz. 525 Viscosity (C-K Models) LOW PRESSURE ACCUMULATOR (CONDENSER TO M|G n PRESSURE Overhead System 5 lbs.
Page 72 1A-46 HEATER A N D AIR C O N D IT IO N IN G from the system fittings rather than the gauge only 23 to 24 inches of vacuum can normally be lines from the adapter. obtained. b. Turn on vacuum pump, and open vacuum Whenever the air conditioning system is open for any control valve (slowly open high pressure side of reason, it should not be put into operation again until it...
Page 73 HEATER A N D AIR C O N D IT IO N IN G 1A-47 vacuum reduces, it indicates a leak in the system or the charging station should read pressures corre gauge connections; locate and repair all leaks. sponding to values listed under PERFORMANCE DATA.
Page 74 1A-48 HEATER A N D AIR C O N D IT IO N IN G the passenger area and resulting in insuffi Floor Mounted System (G Models) cient or no cooling. (Refrigerant Charge — 3 lbs.-4 oz.) Temperature of PERFORMANCE DATA Air Entering 70°...
Page 75 HEATER A N D AIR C O N D IT IO N IN G 1A-49 b. If the quantity drained was less than 4 fluid oz., CHECKING OIL add 6 fluid oz. of new refrigeration oil to the In the six cylinder compressor it is not recommended replacement compressor.
Page 76 1A-50 HEATER A N D AIR C O N D IT IO N IN G REFRIGERANT QUICK-CHECK PROCEDURE The following procedure can be used to quickly determine whether or not an air conditioning system has a proper charge of refrigerant. This check can be made in a manner of minutes thus facilitating system diagnosis by pinpointing the problem to the amount of charge in the system or by eliminating this possibility from the overall checkout.
Page 77 HEATER A ND AIR C O N D IT IO N IN G 1A-51 Fig. 52-Checking Evaporator Inlet and Accumulator Outlet Temperatures M A IN TEN A N C E A N D ADJUSTMENTS 2. Set the control at A/C, HI blower, max COLD and THERMOSTATIC SWITCH run the engine at 2000 rpm.
Page 78 1A-52 HEATER A N D AIR C O N D IT IO N IN G 5. If the outlet temperature was less than the prescribed temperature at the end of each cooling cycle, turn the adjusting screw a partial turn counterclockwise (fig.
Page 79 HEATER A ND AIR C O N D IT IO N IN G 1A-53 3. The system will also indicate a low refrigerant vehicles. The idle compensator is a thermostatically charge by bubbles occurring in the sight glass. controlled air bleed which supplies additional air to the idle mixture.
Page 80 1A-54 HEATER A N D AIR C O N D IT IO N IN G the hose as shown in Figure 55. This should loosen REPAIR OF REFRIGERANT LEAKS the hose so that it may be worked off the fitting. Any refrigerant leaks found in the system should be repaired in the m anner given below: 2.
Page 81 HEATER A N D AIR C O N D IT IO N IN G 1A-55 sure that all of the failed portion is removed. If G and Motor Home Chassis Models only a very small portion of the hose was removed, Removal (Fig.
Page 82 1A-56 HEATER A N D AIR C O N D IT IO N IN G 3 0 7 - 3 5 0 V - 8 C-K MODELS AND MOTOR HOME CHASSIS 4 5 4 V -8 C-K MODELS Fig. 56-Compressor Mountings accomplished by (1) Remove and discard the Compressor Belt Tension Adjustment idler adjustment bolt.
Page 83 HEATER AND AIR C O N D IT IO N IN G 1A-57 replaced it may be necessary to remove and different so it is not possible to establish a hard and fast replace the throttle cable during the belt procedure to follow each time.
Page 84 1A-58 HEATER A N D AIR C O N D IT IO N IN G replaced or flushed, replace the full charge of 10. Introduce R-12 vapor at cylinder (room) tempera oil. If not, add no more fresh oil than was ture and pressure.
Page 85 HEATER A ND AIR C O N D IT IO N IN G 1A-59 3. Disconnect the accumulator inlet and outlet lines 2. Purge the system of refrigerant. and cap or plug the open connections at once. 3. Remove the nuts from the selector duct studs 4.
Page 86 1A-60 HEATER A N D AIR C O N D IT IO N IN G 3. Using needle-nose pliers, remove the expansion 9. Disconnect the vacuum and electrical harness and tube from the evaporator core inlet line (fig. 60). remove the selector duct assembly. 10.
Page 87 HEATER A N D AIR C O N D IT IO N IN G 1A-61 Fig. 62 -Air Selector and Ducts (C-K Models) 8. To reinstall, reverse Steps 1-6 above. Check control Replacement operation. 1. Disconnect the vacuum lines at the tank. 2.
Page 88 1A-62 HEATER A N D AIR C O N D IT IO N IN G BLOWER MOTOR RELAY The blower motor relay is located on the blower side of the blower-evaporator case (fig. 66). Replacement 1. Disconnect the wiring harness at the relay. 2.
Page 89 HEATER AND AIR C O N D IT IO N IN G 1A-63 BLOWER RESISTOR THERMOSTATIC EVAPORATOR SWITCH ASSEMBLY CORE BLOWER RELAY CAPILLARY POSITION IN CORE Fig. 67-Replacing Thermostatic Switch THERMOSTATIC SWITCH Fig. 66-Resistor, Relay and Thermostatic Switch (C-K Models) 5.
Page 90 1A -64 HEATER A N D AIR C O N D IT IO N IN G C O M P O N E N T PART REPLACEMENT OVERHEAD SYSTEM-C-K MODELS The Overhead System is used in conjunction with the Four-Season System. Since replacement of Four-Season System components has been covered previously, only those components peculiar to the Overhead System will be covered in this section.
Page 91 HEATER A N D AIR C O N D IT IO N IN G 1A-65 Fig. 71-Overhead System Front Wiring (C-K Models) the Four-Season System blower-evaporator as shown in Figure 71. Replacement 1. Disconnect battery ground cable. 2. Disconnect the electrical harness at the resistor. 3.
Page 92 1A-66 HEATER A N D AIR C O N D IT IO N IN G EVAPORATOR BLOWER-EVAPORATOR SCREEN UPPER CASE EXPANSION EVAPORATOR VALVE CORE SENSING BULB (C-K Fig. -E x p a n s io n V alve O v e rh e a d S y s te m ) install the new valve assembly using new "O "...
Page 93 HEATER A ND AIR C O N D IT IO N IN G 1A-67 5. Install the blower-evaporator to the roof panel support. 6. Connect the refrigerant lines to the blower- evaporator unit using new "O " rings coated with clean refrigeration oil.
Page 94 1A-68 HEATER AND AIR C O N D IT IO N IN G 9. To install, reverse Steps l-8 above. Add l fluid 2. Lift upward and rearward on the top of the ounce of clean refrigeration oil to a new condenser. distributor duct assembly and move it away from the evaporator and blower motor assembly cover, Use new "O"...
Page 95 HEATER A ND AIR C O N D IT IO N IN G 1A-69 Fig. 77-Sight Glass Replacement EVAPORATOR , BLOWER CONTROL. MOTOR Fig. 78-Air Distributor Duct and Blower-Evaporator Cover (Floor Mounted G Models) 4. Remove evaporator core retaining screws and remove core.
Page 96 1A-70 HEATER A N D AIR C O N D IT IO N IN G 7. Evacuate, charge and check the system. Replacement 1. Disconnect the battery ground cable and compres sor clutch connector. BLOWER MOTOR 2. Remove the blower-evaporator cover as described Removal previously.
Page 97 HEATER A N D AIR C O N D IT IO N IN G 1A-71 pressor damage due to a loss of refrigerant charge is prevented. and the The cause of the refrigerant loss must be corrected system charged prior to replacing the thermal fuse. The super heat switch does not have to be replaced when it cycles and is reusable unless it is determined that the switch is faulty.
Page 98 1A-72 HEATER A ND AIR C O N D IT IO N IN G TOLERANCE ZONE Fig. 85--Thermal Fuse SU CTIO N PRESSURE (PSIG) N O TE: For gauges c a lib ra te d in inches Hg vacuum , d ivid e ga u g e re a d in g by 2 .3 0 6 to o b ta in PSIG.
Page 99 HEATER A N D AIR C O N D IT IO N IN G 1A-73 BLOWER-EVAPORATOR SHROUD This shroud covers the blower-evaporator at the rear of CORRECT the vehicle, and incorporates four adjustable air outlets. BLADE Replacement (Fig. 87) 1. Disconnect the battery ground cable. 2.
Page 100 1A-74 HEATER A N D AIR C O N D IT IO N IN G 6. Remove the blower-evaporator to roof panel attachm ents and lower the blower-evaporator assembly. Remove the assembly and place on a work bench upside down. 7.
Page 101 HEATER A N D AIR C O N D IT IO N IN G 1A-75 Connect the blower lead wires and ground straps. EVAPORATOR CORE (Fig. 90) 1. Disconnect the battery ground cable and compres Install the rear shroud as outlined previously. sor clutch connector.
Page 102 1A-76 HEATER A N D AIR C O N D IT IO N IN G Fig. 92--Condenser (Motor Home Chassis Unit) Fig. 93--Receiver-Dehydrator (Motor Home Chassis Unit) 2. Purge the system of refrigerant. 6. Evacuate, charge and check the system. 3.
Page 103 HEATER A N D AIR C O N D IT IO N IN G 1A-77 2. Purge system of refrigerant. 3. Disconnect inlet and outlet refrigerant lines from the back of unit. Cap or plug all open connections at once. 4.
Page 104 1A-78 HEATER A ND AIR C O N D IT IO N IN G 2. Reverse steps 1-8 of the "Blower Evaporator Assembly" removal procedure. SWITCH 3. Evacuate, charge and check the system. AIR SENSING CAPILLARY THERMOSTATIC AND/OR BLOWER SWITCHES Replacement 1.
Page 105 HEATER A N D AIR C O N D IT IO N IN G 1A-79 pressures. Outlet tube restrictions will be indicated by condenser. Disconnect the blower lead wire and low head pressures and little or no cooling. An repeat the "perform ance check" to determine if the excessively cold receiver-dehydrator outlet may be evaporator pressure can be obtained.
Page 106 C O M P R E S S O R D I A G N O S I S Retrace electrical circuit back to source of power loss. (See wiring diagrams). C-K Models: NO V O LT A G E A T Check for defective discharge Pressure Switch by jumping switch connector terminals.
Page 107 INSUFFICENT C O O L IN G -F O U R SEASON SY STEM (C-K M ODELS) M ove temperature lever rapidly back and forth from max heat to max. cold Listen for temperature door hitting at each end Hitting | Not Hitting I Adjust Door 1 Set Temperature Lever at Detent to the Right of Cold...
Page 108 INSUFFICIENT COOLING DIA GNO SIS CHART (EXCEPT C -K FOUR-SEASON SYSTEM) The fo llo w in g procedures should be applied before perform ance testing an A/C System. 5. Check fo r condenser air blockage due to foreign material. 1. Check fo r proper belt installation and tension w ith J-23600. 6.
Page 109 E L E C T R I C A L S Y S T E M D I A G N O S T I C C H A R T BLOW ER M OTOR IN O P E R A T IV E B LO W E R M O T O R IN O P E R A T IV E (C E R T A IN SPEEDS-EXCEPT HIGH (A N Y S P E E D )
Page 110 ELECTRICAL SYSTEM D IA G N O S T IC CHART BLOW ER M O TO R IN O P E R A T IV E COM PRESSOR C LU TC H IN O P E R A T IV E 1 A T H IG H SPEED O N LY (C-K FO U R -SEASO N SYSTEM ) ...
Page 111 HEATER A ND AIR C O N D IT IO N IN G 1A-85 LOW R EFR IG ER A N T CHARGE PROTECTION SYSTEM DIAGNOSIS CHECK LIST SHOWING POSSIBLE CAUSES AND SUGGESTED CORRECTIONS FOR BLOWN THERMAL FUSE* CORRECTION CAUSE Inspect for leaks, repair, evacuate, recharge system Low refrigerant charge or totally discharged system .
Page 112 1A-86 HEATER AND AIR C O N D IT IO N IN G LOW R EFR IG ER A N T CHARGE PROTECTION SYSTEM CHECK CHECK FOR Supply voltage at clutch coil term inals. E L E C T R IC A L (Com pressor Inoperative, Engine Blown fuse at m ain circuit fuse panel.
Page 113 HEATER AND AIR C O N D IT IO N IN G 1A-87 selector lever positions, a leak is indicated in VACUUM SYSTEM DIAGNOSIS these circuits. (C-K FOUR-SEASON SYSTEM) Start the engine and allow it to idle - move the selector Vacuum Normal at All Positions- lever to each position and refer to the vacuum diagrams If vacuum was normal and even at all positions,...
Page 114 BLOWER MOTOR •BLK- THERMOSTATIC SWITCH DISCHARGE PRESSURE SWITCH CIRCUIT BATT ONLY MED 1 BATT-M1 -RES MED 2 BATT-M2-RES HIGH BATT BLOWER Fig. 104-Four-Season System Wiring Diagram (C-K Models)
Page 116 IGN UNFUSED 10 ORN — 4 2 0 ~ A M P [|~I» INLINE FUSE 16 YEL1 ■16 ORN- RESISTOR FUSE PANEL i 4 i I 52 I 5 0 I J S _ ! 10 PPL' HI BAT | CIRCUIT B A H O NLY BLOWER...
Page 117 GROUND -16 BRN COMPRESSOR I C V ' - , 16 BRN — 4~50~ I.P. WIRING | HEATER CONTROL SUPER SWITCH CONNECTOR HEAT | l 5 0 l 59 SWITCH ^ = > — 18 BLK — «=<§) r - l 18 ORN ■p=t •lh...
Page 118 BLOWER RELAY (REAR) CIRCUIT B A H . O NLY BLOWER B A H . LO MOTOR TIE RELAY MED. B A H LO, MED (REAR) (FRONT TO B A H . L, M, HI REAR) BLOWER SWITCH (FRONT) BLOWER SWITCH (REAR) Fig.
Page 119 ■ f l | TO FUSE PANEL GROUND COMPRESSOR RESISTOR BLOWER SWITCH SET AT CONNECTION N TO NONE N TO I & 2 N TO 1 A 4 HIGH N TO 1, 3 4 4 BLOWER SWITCH THERMOSTATIC SWITCH Fig. 109-Motor Home Chassis Wiring Diagram...
Page 120: Special Tools
1 A-9 4 HEATER A N D AIR C O N D IT IO N IN G SPECIAL TOOLS J-8393 Charging Station J-5403 No. 21 Snap Ring Pliers J-9481 Pulley and Bearing J-24095 Oil Inducer J-643 5 No. 26 Snap Ring Pliers Installer Super Heat Switch J-9393...
Page 121 SECTION IB BODY The following caution applies to one or more steps in the assembly procedure of components in this portion of the manual as indicated at appropriate locations by the terminology "See Caution on page 1 of this Section". THIS FASTENER IS AN IM PORTANT ATTACHING CAUTIO N : PART IN THAT IT COULD AFFECT THE PERFORMANCE OF...
Page 122 1 B-2 BODY Fig. 3—Typical Coach Coach The four-door coach model number is "06". See figure 3. Base models have rear cargo doors. An optional endgate with moveable window is available. Utility Utility models are designated with the number "14". See figure 4.
Page 123 BODY 1 B-3 Fig. 6—Typical "06 " Van LIGHT DUTY TRUCK SERVICE MANUAL...
Page 124 I B 4 BODY C-K MODELS INDEX Replacement............... IB-14 Front End H inges................IB-14 Windshield W ipers............IB-4 Stationary G lass............IB-14 Glove Box............... IB-5 Window and Regulator......... IB-14 Rear View Mirrors............IB-5 Locks, Handles, Rods..........IB-15 Body Glass W eatherstrip.............. IB-16 Windshield Glass............
Page 125 BODY IB - 5 Fig. 8 —Glove Box Fig. 10—Rear View Mirror—Below Eyeline INSTRUMENT PANEL COMPARTMENT AND Adjustment LOCK Engagement of lock in striker may be adjusted by loosening striker retaining screws and moving the striker Replacement to desired position. Removal of the entire assembly including door may be accomplished by removing four screws which attach hinge just below box.
Page 126 1 B-6 BODY INSIDE REAR VIEW MIRROR—FIG. 12 Replacement 1. Remove screw retaining mirror to its glass-mounted bracket and remove mirror. 2. Install mirror into its mounting bracket. Torque screw to specifications. NOTE: Camper mirror installation is similar to the below eyeline mirror installation. Fig.
Page 127 BODY IB - 7 Fig. 14— Applying Pressure to Windshield Fig. 15—Assisting Weatherstrip over Flange 5. With the aid of an assistant outside the cab, remove the windshield from the opening. See figure 16. Checking Windshield Opening Due to the expanse and contour of the windshield it is imperative in the event of a stress crack that the windshield opening be thoroughly checked before installing a replacement windshield.
Page 128 1 B-8 BODY Installation 1. Place a protective covering over front fenders and hood, then apply soapy water to all grooves of the weatherstrip. 2. Install weatherstrip centrally to the body opening, with the pinchweld flange in the inner weatherstrip groove.
Page 129 BODY 1 B-9 BODY SI DOORS bolt, adjust to desired height, and tighten bolt DOOR ADJUSTMENTS securely. Doors can be adjusted for alignment of clearance in the cab door opening, and for proper latching. Door NOTE: This adjustment is im portant to alignment adjustments are made at the striker bolt, and at door hinges.
Page 130 I B - 1 0 BODY assure that the right proportion of door’s DOOR HINGE weight will rest on striker bolt when door is The door check is part of the front door upper hinge. closed. If bolt is positioned too high on pillar, The front door torque rod check holds the door in either rapid wear will occur to the lock cam;...
Page 131 BODY 1B-11 3. Remove arm rest screws and trim panel. See figure channel or frame to soften the old seal. When the seal has softened, remove the glass from the channel. 4. Remove screws attaching ventilator lower assembly to door panel. 2.
Page 132 1B-12 BODY TO ADJUST T E N S IO N S TURN THE VENT WHILE HOLDING A WRENCH O N THE HEX NUT____ Fig. 30—Door Window and Regulator Fig. 28—Adjusting Tension WINDOW REGULATOR—FIG. 30 2. Remove window regulator handles using tool Replacement J-7797.
Page 133 BODY 1B-13 Door Lock Assembly Replacement 1. Raise window to gain access to lock. 2. Remove regulator handle. 3. Remove remote control push button knob. 4. Remove trim panel. 5. Remove clip from inside handle rod-to-lock. 6. Remove clip from outside handle rod-to-lock. This is best accomplished by inserting a long screwdriver through the daylight opening, as shown in figure 32.
Page 134 1B-14 BODY DOOR TO BODY OPENING WEATHERSTRIP—FIGS. 35, 36 Side door sealing incorporates an inner seal. The inner seal is mounted on the body opening welding flange and goes completely around the periphery of the opening. The molded weatherstrip material is snapped in place. Success of weatherstrip replacement depends entirely upon the quality of the cement used and the care with which it is applied.
Page 135 BODY I B - 1 5 channel. See figure 40. Disengage roller from 4. Install regulator by reversing above procedure. channel. Lubricate regulator gear with lubriplate or equivalent. 5. Tilt window outboard and move until other roller can be removed from channel. 6.
Page 136 1B-16 BODY 3. Remove two screws securing outside handle to door panel. 4. Remove handle assembly. 5. Replace by reversing above procedure. Be sure to use new clip when attaching control rod to lock assembly. WEATHERSTRIP—FIG. 44 The procedure outlined in Front Door W eatherstrip may be applied to the Rear Side Door W eatherstrip, shown in figure 44.
Page 137 BODY I B - 1 7 Fig. 45— Rear Door Controls LOCKS, HANDLES AND RODS The rear door lock, outside handle, lock cylinder, control rods and latch are shown in figures 45 and 46. The rods can be disconnected from the lock, latch or handle by disengaging the retaining clips, as shown.
Page 138 I B - 1 8 BODY WEATHERSTRIP W eatherstrip installation is shown in figures 48 and 49. Proper installation is dependent on completely cleaning all foreign material from old installation and using a quality cement on the new installation. R E A R D O O R —F IG . 47 Replacement 1.
Page 139 BODY 1B-19 ENDGATES (0 6 A N D 14) Coach models (06) and utility models (14) use endgates of similar, yet distinct design. Separate procedures follow for service on each of these endgates. ENDGATE ASSEMBLY- (06) MODELS ONLY Replace 1. Lower endgate, and remove hinge access covers. See figure 50.
Page 140 1B-20 BODY Fig. 53—Window Glass and Regulator— (06 Only) Fig. 54—Outside Handle (06 and 14) 8. Unclip and remove inner and outer seal assemblies. ENDGATE ASSEMBLY— 9. Remove screws connecting window regulator assembly to endgate, figure 53, and remove (14) MODELS ONLY regulator.
Page 141 BODY IB -2 1 disconnect support cables from endgate. See figure 4. Remove endgate by pulling disconnected hinge from body, figure 56, then grasping torque rod with one hand and pulling torque rod over gravel deflector, as shown in figure 57. 5.
Page 142 1B-22 BODY 5. Remove torque rod retaining bracket on lower edge 5. Refer to figure 63 for installation of latch control of endgate. See figure 59. and blockout rod. 6. Remove torque rod retaining clip on side edge of 6. Disconnect blockout rod from control assembly by endgate.
Page 143 BODY 1B-23 Fig. 66—Disconnecting Sash from Regulator Fig. 64—Removing Control Assembly and Inside Handle 13. Remove glass from endgate. 14. Remove four regulator attaching screws and withdraw regulator from endgate as shown in figure 15. Remove outside handle by removing nuts from inside of outer panel.
Page 144 I B - 2 4 BODY screws attaching both trunnions to body, and lifting the 4. Lower the door windows. tailgate off the vehicle. 5. Slide top rearward approximately 18" to expose the The tailgate shown in figure 70 can be separated from bottom rear top-to-pickup box attaching holes.
Page 145 BODY 1B-25 cleaning. Vacuum area to remove excess loose dirt. SEATS Always clean at least a full trim panel or section of trim. Care and Cleaning Mask adjacent trim along stitch or weld lines. Mix of Interior Soft Trim detergent type foam cleaners in strict accordance with Dust and loose dirt that accumulate on interior fabric directions on label of container.
Page 146 1B-26 BODY SEAT MOUNTING Typical Seat Mounting provisions are shown in figures 73 through 81. See CAUTION on page 1 o f this CAUTIO N : section regarding fasteners used on seats and seat belts. Fig. 75—Passenger’s Bucket Seat (03) Fig.
Page 147 BODY I B - 2 7 Fig. 78—Rear Bench Seat (63) Fig. 80—Rear Folding Seat (06) Fig. 79—Rear Bench Seat (06) Fig. 81—Rear Bench Seat (14) LIGHT DUTY TRUCK SERVICE MANUAL...
Page 148 1B-28 BODY BODY MOUNTING The sequence of mounting attachments is shown in figures 82 through 85. LIGHT DUTY TRUCK SERVICE MANUAL...
Page 149 BODY 1B-29 Fig. 84—Body Mounting (06) Fig. 85—Body Mounting (14) LIGHT DUTY TRUCK SERVICE MANUAL...
Page 150 1B-30 BODY G MODELS INDEX Locks, Handles, Rods...........IB-37 Front End Windshield Wipers............IB-30 Sliding Side Door Cowl Ventilator G rille..........IB-31 Front Latch...............IB-38 Side Ventilator Valve...........IB-31 Rear Latch................IB-39 Rear View M irror............IB-32 Upper Left H inge............IB-39 Door Strikers..............IB-40 Body Glass Windshield Glass............IB-32 Adjustments...............IB-40 Stationary Glass..............IB-34...
Page 151 BODY 1B-31 Fig. 2G— Windshield Wiper Linkage 3. Install outside air cowl ventilator grille to top of COWL SIDE VENT VALVE cowl. Replacement 4. Before installing wiper arms, operate wiper motor 1. Remove screws retaining valve guide to panel, as momentarily which should rotate pivot shafts to shown in figure 4G.
Page 152 1B-32 BODY REAR VIEW MIRRORS Inside Rear View Mirror Replacement The inside mirror may be removed by removing screw retaining mirror to its glass-mounted bracket, and lifting mirror off bracket. Outside Rear View Mirrors Outside rear view mirror installations are shown in figure 6G.
Page 153 BODY I B - 3 3 3. Check flange area for solder, weld high spots, or hardened spot-weld sealer. Remove all high spots. 4. Check windshield glass to opening, by supporting glass with six spacers contained in packet J-22577, as shown in figure 8G. Do not strike glass against body CAUTION: metal.
Page 154 1 B -34 BODY Fig. 11G—Swingout Window d. Seal windshield to weatherstrip and weatherstrip to body. SWINGOUT WINDOW Removal 1. Swing out the window. See figure 11G. 2. Remove screws retaining latch to body. 3. Remove window hinge retaining screws and window.
Page 155 BODY 1B-35 possible. Alignment adjustments can be made by loosening the proper hinge bolts, aligning door to proper position, and tightening bolts securely. See figure 12G, for typical adjustments. Striker Bolt Adjustment W ith the use of J-23457, shown in figure 13G, the striker bolt can be adjusted in any of three ways.
Page 156 1B 3 6 BODY 1. Open door and block open. 2. Remove side door weatherstrip. 3. Remove used adhesive from door with adhesive or cement remover. 4. Apply adhesive to door. 5. Install weatherstrip. 6. Trim weatherstrip with a notch, and butt ends together.
Page 157 BODY 1B-37 2. Make certain the rubber lip is positioned before tightening screws. 3. Slide door glass forward engaging glass in vent channel. 4. Reinstall all screws and tighten. 5. Install and tighten the three screws at the upper front of the door. Adjustment 1.
Page 158 1B-38 BODY 5. Check all controls for proper operation before NOTE: Connecting rod can be removed at reinstalling trim and handles. this point by disconnecting spring clip from lock. 6. Install remote control sill knob. 4. To install, reverse removal procedure. REMOTE CONTROL AND CONNECTING ROD—FIG.
Page 159 BODY 1B-39 Fig. 21G—Sliding Door Front Latch 23G— Door Rear Latch Fig. S lid in g 3. Install access covers and trim panels (if so REAR LATCH AND/OR LATCH ACTUATING equipped). RODS 4. Adjust door rear latch as outlined under "Door Adjustments".
Page 160 1B-40 BODY 1. Roller 8. Bolt 15. Screw 2. Lockwashers 9. Plate Guide Block Bushing 3. Nut 10. Upper lines Hinge (Body Half) Hinge (Door Half) 4. Cam 11. Spacer Spring 5. Washer 12. Spring (Upper Lever) 19. Bushing Spring retainer 6.
Page 161 BODY 1B-41 In and Out Front in and out adjustments, figure 26G, are provided by means of an adjustable lower roller mounting bracket, and for the upper front in and out adjustment the upper bracket is slotted so the roller can be moved in and out. Rear in and out adjustment is provided by adjusting the rear lock striker laterally.
Page 162 1B-42 BODY 5. Adjust upper left hinge stop as outlined under "U pper Left Hinge Latch and Stop Adjustment". Reposition Door "In " or "Out" 1. Loosen front latch striker. 2. Loosen upper front roller from its bracket. between the bolt and body pillar. The striker must enter the lock freely.
Page 163 BODY 1B-43 adding or deleting shims between the striker and body to provide at least .10 inch of lever contact. Also, striker must be positioned at least .06" above bottom of striker tang. See figure 30G. 2. Adjust fore and aft (centering door in opening) by moving striker horizontally.
Page 164 1 B -44 BODY REAR DOORS REAR DOOR HINGE STRAP REAR DOOR REMOTE CONTROL Replacement Removal 1. Remove strap release pin. See figure 33G. 1. Remove trim panel. 2. Remove screws retaining strap to door. 2. Disengage upper and lower latch rods from control by removing retaining clips.
Page 165 BODY 1B-45 NOTE: When reinstalling the lower latch rod REAR DOOR GLASS AND WEATHERSTRIP to control, the short straight section attaches Removal and installation procedures are the same as for to the latch. the stationary body side windows. Refer to those 2.
Page 166 I B - 4 6 BODY Fig. 37G—Door Wedge Adjustment SEATS See CAUTION on page 1 of t h i s CAUTION: Installation 1. Install seat riser to floor. Torque bolts to section regarding fasteners used on seats and specifications. seat b e l t s .
Page 167 BODY 1 B-47 PASSENGER SEAT—MOUNTING installation 1. Attach leg and support assembly to seat. Torque to BRACKETS specifications. Removal 1. Remove seat and brackets from seat riser. See 2. Attach seat belts. Torque bolts to specifications. figure 39G. 2. Remove brackets from seat. Shoulder of Bolt must bottom on CAUTION: weld nu t.
Page 168 1B-48 BODY SPECIAL TOOLS m m m m m r 1 - J-2189 Weatherstrip Tool Set 2. J-22585 Front Door Hinge, Bolt Wrench 3. J-22577 Windshield Checking Blocks 4. J-7797 Door Handle Clip Remover 5. J-23457 Door Striker Bolt Remover and Installer Fig.
Page 169 SECTION 2 FRAME INDEX Description 10-30 Series Truck .2-1 Frame Repair..............2-2 .2-1 W elding................2-2 M aintenance........2-1 Bolting..................2-2 Frame Alignment..... Horizontal C heck....2-2 Underbody A lignm ent.............2-2 Vertical Check......DESCRIPTION The G-Van frame side rails, cross sills and outriggers are Light duty 10-30 Series frames are of the ladder channel part of the underbody assembly which is a welded unit.
Page 170 2-2 FRAME 2. Dimensions must be within 3/16". drilled at the starting point of the crack to prevent spreading. Widen V groove crack to allow complete weld 3. If a tram bar is used, for horizontal alignment "X " penetration. - check from opposite and alternate reference points AA, BB and CC, as illustrated by the lines in NOTE: Do not weld into corners of frame or...
Page 171 Fig. 2- Frame Horizontal Checking - Typical...
Page 172 2 -4 FRAME Fig 3--KA Frame Model CA107 9 - 3 /8 1 1 -7 /8 1 3 -3 /8 16 1 0 -1 /4 7 - 1 /8 10 1 3 - 3 /8 1 5 -1 /2 12 11 -3 /8 1 3 - 3 /8 43 1 2 7 -3 /4 14 1 6 -7 /8 1 9 -1 /8 1 6 - 7 /8...
Page 173 Fig. 4-10-30 Series Truck Frame...
Page 174 2-6 FRAME LIGHT DUTY TRUCK SERVICE MANUAL...
Page 175 SECTION 3 FRONT SUSPENSION The following caution applies to one or more steps in the assembly procedure of components in this portion of the manual as indicated at appropriate locations by the terminology “See Caution on page 1 of this Section”...
Page 176 3-2 FRONT SU S PEN SIO N Steering Knuckle/Steering Arm......... .3-25 Front Suspension..............3-27 Removal................3-26 Ball Joint................3-30 Installation................3-26 Shock Absorber..............3-31 Crossmember and Suspension Unit........3-26 On Vehicle................3-31 Removal................3-26 Bench..................3-32 Installation................3-26 Bearings and Races..............3-33 Diagnosis................. .3-27 Special Tools................3-37 GENERAL DESCRIPTION The GM 10-30 series Truck line except K Series U-bolts.
Page 177 G 10-20 C 10 P 10-30 Fig. 2—Front Suspension C -P -K Typical...
Page 178 3-4 FRONT SU SPEN SION Fig. 3—Wheel Hubs and Bearings THEORY OF OPERATION The front suspension can be divided into two types, the The steering knuckle and wheel spindle attach to the axle CONVENTIONAL, such as used on General Motors K Series ends through ball joints.
Page 179 FRONT S U S PEN SIO N rigid axle and one of them passes over a bump the axle bolted to the steering knuckle. This arrangement allows executes an angular movement in the (front view) the front wheel suspension to move up and down with vertical plane and both of the wheels perform respect to the vehicle frame (spring action) and swing at movements of the same angular magnitude.
Page 180 3-6 FRONT SU SPEN SION BALL JOINT ASSEMBLY UPPER MOUNT SEAL COVER SEAL SEAL SPRING ROD GUIDE REBOUND SPRING CYLINDER TUBE PISTON NUT CYLINDER END BASE CUP COMPRESSION Fig. 5—Ball Joints-Typical VALVE CAGE body while at the same time controlling wheel and axle LOWER MOUNT RELIEF VALVE motions.
Page 181 FRONT S U S P E N S IO N This cell, in the reservoir, acts the same as an air chamber, expanding and contracting to compensate for the volume of the piston rod. But since it is a gas filled cell, there is no free air to mix with the fluid;...
Page 182 3-8 FRONT SU SPEN SION EXTEN SIO N FORCE INTAKE VALVE SPRING COMPRESSION HIGH SPEED VALVE ASSY. ORIFICE --------- VALVE CAGE ■* VALVE STEM BLOW OFF SPRING VALVE RESERVOIR COM PRESSION RETAINER WASHER LOW SPEED ORIFICE CYLINDER END Fig. 11—Shock Absorber Rebound Cut Off Schematic Fig.
Page 183 FRONT SU S PEN SIO N COMPRESSION BACK WASHER SIDE INTAKE SPRING INTAKE VALVE DISC PISTON-HIGH SPEED ORIFICE TYPICAL REBOUND ORIFICE DISC REBOUND SPRING DISC REBOUND LO W SPEED SIDE SPACING SPRING DISC ORIFICE SPRING SEAT REBOUND SPRING — BLOW-OFF PISTON ASSEMBLY VALVE PISTON NUT "...
Page 184 3 -1 0 FRONT SUSPENSION the same for both arms. Toe-out on turns is not CAMBER adjustable. Camber is the tilting of the front wheels from the vertical when viewed from the front of the vehicle. STEERING AXIS INCLINATION (S.A.I.) FIG. 17 When the wheels tilt outward at the top, the camber is Steering axis inclination (form ally called kingpin said to be positive ( + ).
Page 185 FR ON T S U S PEN SIO N 3-11 Fig. 16—Toe-out on Turns LIGHT DUTY TRUCK SERVICE MANUAL...
Page 186 3 12 FRONT SU SPEN SION LEFT HAND FRONT VIEW Fig. 17—Steering Axis Inclination MAINTENANCE A N D ADJUSTMENTS See CAUTION on page 1 of this Movement greater than .008" (.010" on CAU TIO N : section regarding the fasteners referred to in K-Series) indicates a loose bearing.
Page 187 POSITIVE applicable), or whenever for other reasons the alignment c. A ” frame angle must be is being reset, Chevrolet recommends that the specifica “ DOWN IN REAR to a caster reading. tions given in column 3 of the aforesaid applicable chart...
Page 188 3 -1 4 FRONT SU S PEN SIO N Vehicles within these tolerances from the mean specification are safe and not hazardous with respect to <L OF WHEEL <L OF WHEEL alignment effects on operation and handling. Settings outside these limits are not necessarily unsafe, however, customer dissatisfaction, due to steering pull or tire wear may occur or the vehicle may be in a damaged condition.
Page 189 FRONT S U S PEN SIO N 3 -1 5 HORIZONTAL FRAME ANGLE = 1V4° DOWN FRAME ANGLE = ’ / a0 DOWN CASTER ANGLE READING = - ( IV ■CASTER ANGLE READING = + (2!4°) ACTUAL (CORRECTED) CASTER ANGLE = + (1 °...
Page 190 3 -1 6 FRONT SU SPEN SION PIVOT SHAFT OUTBOARD OF FRAME CASTER CAMBER FORWARD Fig. 21— Caster - Camber Adjustment Fig. 22—Toe-in Adjustment C O M PO N EN T PARTS REPLACEMENT 3. Remove hub and disc assembly. WHEEL HUBS, BEARINGS (Fig. 23) 4.
Page 191 FRONT S U S PEN SIO N 3 -1 7 brake discs for out-of-round or scored conditions and check bearing outer races for looseness in hubs. Repairs Replacement o f Bearing Cups If necessary to replace an outer race, drive out old race from the hub with a brass drift inserted behind race in notches in hub.
Page 192 3 -1 8 FRONT SU SPEN SION Fig. 25—Shock Absorber - C, P and G Typical Fig. 26B—Stabilizer Bar K-Typical NOTE: Slit in bar to frame bushings should be facing forward. 1. Place stabilizer in position on frame and install frame brackets over bushings.
Page 193 FRONT S U S PEN SIO N 3 -1 9 Installation See CAUTION on page 1 of this CAUTION: section regarding the fasteners referred to steps 3 and 4. 1. Properly position spring on the control arm, and lift control arm using jack and tool J-23028. 2.
Page 194 3 -2 0 FRONT SUSPENSION LOWER CONTROL ARM INNER PIVOT SHAFT AND/OR BUSHING REPLACEMENT C20-30, G30, P10-30 (Steel Bushings) Lower—Removal (Fig. 29) 1. Raise vehicle and support the frame so that control arms hang free. 2. Position an adjustable floor jack under the control arm inboard of spring and into depression in lower arm.
Page 195 FRONT SU S PEN SIO N 3-21 Installation J—24435-7 See CAUTION on page 1 of this CAUTIO N : section regarding the fasteners referred to in steps 4 and 5. 1. Install shaft to control arm and install end nuts. Do not torque nuts at this time.
Page 196 3 -2 2 FRONT SUSPENSION 2. Install remover J-24435-1, receiver J-24435-3 and LOWER CONTROL ARM ASSEMBLY "C " clamps J-24435-7 as shown in Figure 32A. Removal 3. Tighten the clamp to draw out the old bushing. 1. Raise vehicle on hoist and remove spring as Discard old bushing.
Page 197 FRONT SU S PEN SIO N 3 -2 3 J-24435-7 J-24435-6 Fig. 33B—Lower Control Arm Rubber Bushing Fig. 33C—Lower Control Arm Rubber Bushing Removal Installation 3. Install a chain over the upper arm inboard of the Be sure spacer J-24435-6 i s i n CAUTION: stabilizer and outboard of shock absorber as a position as shown i n figure 33C t o avoid...
Page 198 3 -2 4 FRONT SU SPEN SION torque to align cotter pin not to exceed 130 ft. lbs. Never back off to align cotter pin. 4. Install new cotter pin. 5. Install lube fitting and lube new joint. . Install brake caliper assembly if removed (see section 5).
Page 199 F RONT S U S PEN SIO N 3 -2 5 caliper assembly and wire it to the frame to 7. Install Tools J-9519-10 and J-9519-7 as shown in Fig. 36. gain clearance for tool J-23742. See section 5 for proper procedure. NOTE: It will be necessary to alter Tool J-9519-10 as illustrated in Fig.
Page 200 3 -2 6 FRONT SU SPEN SION remains compressed, yet the wheel and steering knuckle assembly remain accessible. If a frame hoist is used, support lower control arm with an adjustable jackstand to safely retain spring in its curb height position. Removal 1.
Page 201 FRONT SU S PEN SIO N 3-27 FRONT SUSPENSION D IA G N O S IS HARD STEERING Probable Cause Probable Remedy a. Ball joints and steering linkage need lubrication a. Lubricate ball joints and linkage b. Low or uneven front tire pressure b.
Page 202 3 -2 8 FRONT SU SPEN SION N O IS E IN F R O N T EN D P r o b a b l e C a u s e P r o b a b l e R e m e d y a.
Page 203 FRONT SU S PEN SIO N 3 -2 9 “ D O G " T R A C K IN G P r o b a b l e R e m e d y P r o b a b l e C a u s e LEAF TYPE REAR SPRING a.
Page 204 3 -3 0 FRONT SU SPEN SION B A L L J O IN T D IA G N O S T IC P R O C E D U R E Fig. 43—Ball Joint Diagnostic Procedure except K Series LIGHT DUTY TRUCK SERVICE MANUAL...
Page 205 FRONT SU S PEN SIO N 3-31 the up and down motion stops very quickly. If up and SHOCK ABSORBER down motion continues longer at one corner when DIAGNOSIS compared to opposite corner (example, both front shocks), the one having the longer up and down motion ON VEHICLE CHECKS may be suspect.
Page 206 3 -3 2 FRONT SU SPEN SION movement of the front shocks during the compression stroke. Compare the rebound resistance between both front shocks, then compare the compression resistance. If a noticeable difference can be felt during either stroke, usually the shock having the least resistance is at fault.
Page 207 FRONT SU S PEN SIO N 3 -3 3 AIR ADJUSTABLE SHOCKS TYPICAL REAR SHOCK TYPICAL FRONT SHOCK This type of shock contains an air chamber like the - U r spiral groove reservoir type, and must have the air purged from the working chamber.
Page 208 3 -3 4 FRONT SU S PEN SIO N DIAGNOSIS FRONT WHEEL, PINION, DIFFERENTIAL SIDE AND REAR WHEEL ROLLER BEARINGS EXCESS NOISE C O M PLA IN T D IAG NO STIC PROCEDURE Check tires for irregular wear Check tire pressure Road Test Check lubricant level Drive to warm-up rear axle...
Page 209 FRONT SU S PEN SIO N 3 -3 5 FRONT WHEEL B E A R IN G D IA G N O S IS CONSIDER THE FOLLOWING FACTORS WHEN DIAGNOSING BEARING CONDITION: 1. GENERAL CONDITION OF A LL PARTS DURING DISASSEMBLY AND INSPECTION. 2.
Page 210: Front Suspension
3 -3 6 FRONT SUSPENSION FRONT WHEEL BEARING DIAGNOSIS (CONT’D) C R A C K E D I N N E R RACE FATI GUE S P A L L I N G BRINELLI NG RACE CRACKED DUE TO IMPROPER FIT, FLAKING OF SURFACE M ETAL RESULTING FROM SURFACE INDENTATIONS IN RACEWAY CAUSED BY COCKING, OR POOR BEARING SEATS.
Page 211 FRONT SUSPENSION 3-37 Bearing Race Installer J-8457 J-8092 Driver Handle Bearing Race Installer J-8458 J-9519-9 Ball Joint Installer Bearing Race Installer Ball Joint Remover J-8849 J-9519-7 Bearing Race Installer J-9519-10 "C " Clamp J-9276-2 Spring Remover J-23028-01 Bushing Replacement J-24435-1 10 .
Page 212 3-38 FRONT SUSPENSION FOUR WHEEL DRIVE (SERIES K10 AND K20) INDEX General D escription............3-38 Removal................343 Front A xle................3-38 Installation................. 343 Transfer Case..............3-38 Disassembly..............343 Adapter Assembly............3-38 Wheel H ub..............343 Free Wheeling Hubs............3-38 Spindle................344 Maintenance and Adjustments........
Page 213 FR O N T SU S PEN SIO N 3 -3 9 MAINTENANCE A N D ADJUSTMENTS 3. At top of knuckle, apply torque wrench to one of BALL JOINT ADJUSTMENT the steering arms attaching stud nuts, then check Front axle ball joint adjustment is generally necessary torque necessary to turn the steering knuckle.
Page 214 3 -4 0 FRONT SU SPEN SION CO M PO N EN T PARTS REPLACEMENT FREE-WHEELING HUB Disassembly The free wheeling hub assemblies used on the front 1. Remove actuator knob and “O ” ring from wheels are serviceable. retaining plate, discard “O” ring and replace with a new “O ”...
Page 215 F R ON T S U S PEN SIO N 3-41 3. Inspect all parts for wear, cracks for broken teeth NOTE: Spring is an interference fit. When and replace as necessary. spring is seated, spring extends past the spindle nuts by approximately 7/8” . 4.
Page 216 3 -4 2 FRONT SU SPEN SION SPRING RETAINER PLATE INNER CLUTCH RING AXLE SHAFT SNAP RING OUTER CLUTCH RETAINING RING AXLE SHAFT SLEEVE AND RING O ” RING ACTUATING ACTUATOR KNOB CAM BODY “ O " RING WASHER INTERNAL SNAP RING BUSHING HUB RING...
Page 217 FRONT SU S PEN SIO N 3 -4 3 Fig. 55—Front Drive Axle Assembly 5. Connect brake hoses to frame fittings bleed the all fitting ends or cover with a rag to prevent brake system (see Section 5). contamination. 5. Disconnect shock absorbers from axle brackets. .
Page 218 3 -4 4 FRONT SU SPEN SION 4. Remove the wheel bearing outer lock nut, lock ring, and wheel bearing inner adjusting nut using Tool J-6893 and Adapter J-23446 or tool J-6893-01. (See fig. 58). 5. Remove the disc assembly, outer wheel bearing and the spring retainer plate.
Page 219 FRONT SU S PEN SIO N 3 -45 Fig. 58—Removing Wheel Bearings Fig. 61—Removing Steering Arm Nuts 10. To remove the tie rod: a. Remove cotter pins. b. Loosen tie rod nuts and tap on nut with a soft hammer to break the studs loose from the knuckle arm.
Page 220 3 -4 6 FRONT SU SPEN SION J -2 3 4 5 4 -1 BALL JOINT J-23454-2 J-638 FLAT WASHER J-9519-10 (HIDDEN) J-951 9-10 Fig. 6 3 — R e m o v in g Lower B all J o in t Fig.
Page 221 FRONT S U S PEN SIO N 3 -4 7 cotter pin hole in the stud end) is straight. Press the . Torque the upper ball socket nut to 100 ft. lbs. as stud into the knuckle until properly seated using shown in Figure .
Page 222 3 -4 8 FRONT SU S PEN SIO N lbs. (while rotating hub) to seat the bearings using Assemble Spindle Components: a. Place the spindle in a vise on the high step and Tool J-6893 and Adapter J-23446 or J-6893-01. Back install needle roller bearing using Installer off the inner adjusting nut and retorque to 35 ft.
Page 223 FRONT S U S PEN SIO N 3 -4 9 SPECIAL TOOLS Bearing Race Installer 6. J-6382-3 Sleeve . J-6368 2. J-6893-01 Bearing Installer 7. J-23447 Adjusting Sleeve Spanner 8. J-2 3448 Cup and Seal Installer 3. J-8092 Driver Handle 9.
Page 225 REAR S U S PEN SIO N A N D DRIVELINE SECTION 4 REAR SUSPENSION AND DRIVELINE The following caution applies to one or more steps in the assembly procedure of components in this portion of the manual as indicated at appropriate locations by the terminology "See Caution on page 1 of this Section".
Page 226 4 -2 REAR SU S PEN SIO N AND DRIVELINE Fig. 2—Typical G-Truck Rear Suspension CO M PO N EN T P/ REPLACEMENT 5. Remove shock absorber from vehicle. SHOCK ABSORBERS . To install shock absorber, place into position and Replacement reattach at upper mounting location.
Page 227 REAR S U S P E N S IO N A N D DRIVELINE Fig. 6—Shock Absorber—G-10, 20, 30 4. Remove brackets from anchor plates by removing STABILIZER SHAFTS attaching screws. Refer to figures 9, 10 and 11 for specific rear stabilizer 5.
Page 228 4 -4 REAR SU S PEN SIO N AND DRIVELINE ‘ NOTE: Torque nut by running nut to unthreaded portion of link bolt. Fig. 10—Rear Stabilizer Shaft—C-20(63), C-30 Fig. 11—Rear Stabilizer Shaft—P-30 2. Loosen, but do not remove, spring-to-shackle LEAF SPRING ASSEMBLY retaining nut.
Page 229 REAR S U S P E N S IO N A N D DRIVELINE Fig. 13—Rear Spring Installation—C-K Models LIGHT DUTY TRUCK SERVICE MANUAL...
Page 230 4 -6 REAR S U S PEN SIO N AND DRIVELINE Fig. 15—Rear Spring Installation—P30 Bushing Replacement Spring Leaf Replacement 1. Place spring on press and press out bushing using a 1. Place spring assembly in a bench mounted vise and suitable rod, pipe or tool as shown in figure 16.
Page 231 REAR SU S PEN SIO N A N D DRIVELINE Leaf Spring Installation SHACKLE REPLACEMENT 1. Position spring assembly to axle. Make sure spring 1. Raise vehicle on hoist. Place adjustable lifting device under axle. is in position at both spring hangers. 2.
Page 232 4 -8 REAR S U S PEN SIO N AND DRIVELINE PROPELLER SHAFT INDEX ..........4-8 Theory of Operation....Component Parts Replacement ..........4-9 the alternate deceleration and acceleration of the second THEORY OF OPERATION joint. When the two joints do not run at approximately the same angle, operation can be rough and an Universal Joints objectionable vibration can be produced.
Page 233 REAR S U S PEN SIO N A N D DRIVELINE 4 -9 length, diameter and the type of splined yoke. On some models the drive shaft is made up of concentric steel tubes with rubber elements between. Each shaft is installed in the same manner. A universal joint and splined slip yoke are located at the transmission end of the shaft, where they are held in alignment by a bushing in the transmission rear...
Page 234 4 - 1 0 REAR SU S PEN SIO N A ND DRIVELINE Removal 1. Raise vehicle on hoist. Mark relationship of shaft to companion flange and disconnect the rear universal joint by removing trunnion bearing "U " bolts or straps. Tape bearing cups to trunnion to prevent dropping and loss of bearing rollers.
Page 235 REAR S U S PEN SIO N A N D DRIVELINE 4-11 CENTER SUPPORT BEARING—FIG. 27 CAUTION: See CAUTION on page 1 of t h i s section regarding Center Support Bearing fasteners. 1. Remove dust shield. 2. Remove strap retaining rubber cushion from bearing support.
Page 236 4 -1 2 REAR SU S PEN SIO N A ND DRIVELINE c. Start bearing and slinger assembly straight on shaft journal. Support propeller shaft and, using ALIGNMENT suitable length of pipe over splined end of shaft, press bearing and inner slinger against shoulder on shaft.
Page 237 REAR S U S PEN SIO N A N D DRIVELINE 4 -1 3 . Remove front trunnion from center and front yoke in same manner as described in Steps 2, 3 and 4. NOTE: Before front trunnion can be removed all four (4) bearing caps must be removed.
Page 238 4 - 1 4 REAR SU SPEN SION AND DRIVELINE PROPELLER SHAFT A N D UNIVERSAL JO IN T D IA G N O S IS 4. Stop engine and check for any mud or undercoat Checking and Correcting ing on the propeller shaft. If any is found, remove Propeller Shaft Unbalance—Vehicles with it and again check the intensity of the vibration.
Page 239 REAR S U S P E N S IO N A N D DRIVELINE 4 -1 5 COMPLAINT POSSIBLE CAUSE CORRECTION Roughness, Vibration or a. Bent or dented drive shaft. a. Replace. Body Boom at any speed. b. Undercoating on drive shaft. b.
Page 240: Rear Axle
4 -1 6 REAR SU S PEN SIO N A N D DRIVELINE REAR AXLE INDEX General Description............4-16 10-1/2" and 12-1/4" Ring G ear......4-29 Theory of Operation............4-20 Axle Assembly............. 4-29 Component Parts Replacem ent........4-25 Axle Shaft..............4-29 8-7/8"...
Page 241 REAR S U S PEN SIO N A N D DRIVELINE 4 -1 7 19. Retainer Screw 10. Straddle Bearing Companion Flange 20. Bearing Cap 11. R ing Gear Oil Deflector 21. Case-to-Ring Gear Bolt 12. D ifferential Spider Oil Seal 22.
Page 242 4 -1 8 REAR SU S PEN SIO N AND DRIVELINE P in io n N u t P in io n R e ar B e a rin g D iff e r e n t ia l S p id e r W asher D riv e P in io n D iff e r e n t ia l S id e G ear...
Page 243 REAR S U S P E N S IO N A N D DRIVELINE 4 - 1 9 Fig. 37— 12-1/4" Ring Gear Axle—11,000# Capacity and also between differential pinions and the differential 12-1/4" Ring Gear Axle case. (11,000 Pound Capacity) A thrust pad mounted on the end of an adjusting screw The 11,000 lb.
Page 244 4 -2 0 REAR S U S PEN SIO N A N D DRIVELINE THEORY OF OPERATION- STANDARD DIFFERENTIAL The differential has two basic functions. First, it transmits torque from the propeller shaft, through a 90° turn, to the rear wheels. Second, it takes the torque provided by the propeller shaft and divides this torque as necessary to allow each wheel enough torque to rotate as conditions require.
Page 245 REAR SU S P E N S IO N AND DRIVELINE 4-21 Differential Operation A differential is an arrangement of gears that divides the torque between the axle shafts and allows them to rotate at different speeds. A basic differential consists of a set of four gears.
Page 246 4-22 REAR SUSPENSION AND DRIVELINE mishandling in storage and installation. They are portion of the outer race can be exposed. In cases where adversely affected by dirt and they should be protected the entire face of the outer race is exposed, a section of from rust and corrosion.
Page 247 REAR SUSPENSION AND DRIVELINE 4-23 Installation Procedures Before pressing a bearing back on the shaft, the bearing seat should be thoroughly cleaned of all dirt, carbonized lubricant or any other foreign matter present. Not only may such things cause scoring of the shaft and the bearing bore, but an improper bearing installation may result.
Page 248 4 - 2 4 REAR SU S PEN SIO N AND DRIVELINE 3) 1 r— ^ 1 PRESS R A M _ _ STEEL BLOCK PIPE O R W R O N G RIGHT "‘" 'T U B E IE _ _tl D . . . £ ..
Page 249 REAR S U S PEN SIO N A N D DRIVELINE 4 -2 5 . Never hammer directly on races or rollers, and never use a wooden or soft metal mallet, as chips or splinters may enter the bearing. 7. Use many smart quick taps rather than a few heavy ones.
Page 250 4 -2 6 REAR SU S PEN SIO N A ND DRIVELINE Fig. 51—Differential Pinion Shaft Removal Fig. 53—Wheel Bearing Removal Oil Seal/Bearing—Replacement 1. Remove oil seal by using button end of axle shaft. Insert button end behind the steel case of the oil seal, then pry seal out of bore being careful not to damage seal.
Page 251 REAR S U S PEN SIO N A N D DRIVELINE 4 -2 7 Fig. 55—Seal Installation Fig. 56—Pressing Out Wheel Stud Axle Shaft—Installation . Remove lug nut. 1. Slide axle shaft into place. 7. Reinstall brake drum and wheel and tire. Exercise care that sp li ne s on end of CAUTION: .
Page 252 4 -2 8 REAR SUSPENSION AND DRIVELINE the number of exposed threads on pinion stem, and record for later reference. See figure 58. . Install Tool J-8614-11 on pinion flange and remove pinion flange self-locking washer faced nut as shown in figure 59. (Position J-8614-11 on flange so that the four notches are toward flange.) Save scribed nut for reinstallation.
Page 253 REAR S U S PEN SIO N A ND DRIVELINE 4 -2 9 Permatex Type A or equivalent) prior to installing rear yoke, split rear universal joint, position washer and nut on pinion. propeller shaft to one side, and tie it to the frame side rail.
Page 254 4 - 3 0 REAR SU SPEN SION A ND DRIVELINE Fig. 65—Removing Axle Shaft—11,000 # Axle 3. Thoroughly remove old gasket material from hub and hub cap. Clean shaft flange and mating Fig. 63—Typical Axle Vent Installation surfaces in the wheel hub. locking pliers and twist to start shaft removal.
Page 255 REAR S U S PEN SIO N A N D DRIVELINE 4-31 12 1 1 1 0 9 9 . O il D e fle c to r 1. A x 1 e S h a ft 2 . A x le S h a ft-to - W h e e l 10.
Page 256 4 -3 2 REAR SU S PEN SIO N AND DRIVELINE Haw* * — Fig. 69—Removing Outer Bearing and Cup cleaning solvent. Clean with stiff brush to remove 4. Withdraw cup installer, then install retainer ring, old lubricant. Blow bearings dry with compressed air, directing air stream across bearing.
Page 257 REAR S U S PEN SIO N A N D DRIVELINE 4 -3 3 Fig. 74—Installing Hub Oil Seal assembly is such that replacement cannot be accom Fig. 72—Removing Hub Outer Bearing plished with the hub assembly installed on the vehicle. obtained, and that the adjustment will not 1.
Page 258 4 - 3 4 REAR SU S PEN SIO N AND DRIVELINE 3. Use appropriate tool as listed for the specified axle: a. J-2222 for 10-1/2" axles. b. J-0870 for 12-1/4" lb. axles. 4. Tighten inner adjusting nut to specified torque at the same time rotating hub to make sure all bearing surfaces are in contact.
Page 259 . Lubricate the cavity between the seal lips with a high melting point bearing lubricant. 7. Install a new pinion oil seal into the bore, using J-24434 for Chevrolet 10-1/2” axles, J-24384 for Dana 10-1/2" axles, and J-22281 for 12-1/4" axles. Be sure seal bottoms against shoulder in bore.
Page 260 REAR SU S PEN SIO N AND DRIVELINE Elimination of External Noises Body Boom Noise or Vibration When a rear axle is suspected of being noisy, it is Objectional "body boom" noise or vibration at 55-65 advisable to make a thorough test to determine whether mph can be caused by an unbalanced propeller shaft.
Page 261 REAR S U S PEN SIO N A ND DRIVELINE 4 -3 7 produce a constant rough noise of a lower Side Bearings pitch than pinion bearings. Side bearing noise may also fluctuate in the above wheel bearing test. NOTE: Bearing Diagnosis Charts appear later in this section.
Page 262 4 -3 8 REAR SU SPEN SION AND DRIVELINE A GENERAL DIAGNOSTIC PROCEDURE FOR ISOLATING REAR AXLE NOISE PROBLEMS Cause Problem 1. a) Road noise 1. Noise is the same in drive or coast b) Tire noise c) Front wheel bearing noise 2.
Page 263 REAR S U S P E N S IO N A N D DRIVELINE 4 -3 9 DIFFERENTIAL A N D REAR AXLE BEARING DIAGNOSIS CO NSIDER THE FO LLO W IN G FAC TO R S W HEN D IA G N O S IN G B E A R IN G C O N D IT IO N : G E N E R A L C O N D IT IO N OF A L L PARTS D U R IN G D ISASSEM B LY A N D IN SPECTION 2.
Page 264 4 - 4 0 REAR SU SPEN SION AND DRIVELINE DIFFERENTIAL A N D REAR AXLE BEARING D IA GNOSIS (C O N T ’D) C R A C K E D I N N E R RACE FATIGUE SPALLING B R IN ELL ING RACE CRACKED DUE TO IMPROPER FIT, FLA K IN G OF SURFACE M ETAL RESULTING FROM...
Page 265 Wheel B o lt Remover 23. J-24428 Wheel Hub O il Seal Installer 9. J-8092 Driver Handle 24. J-24434 Pinion O il Seal Installer - Chevrolet 10. J-5853 Torque Wrench - Inch/Pound Wheel Bearing N u t Wrench 25. J-870 11. J-8614-II Companion Flange Holder 26.
Page 267 BRAKES SECTION 5 BRAKES The following caution applies to one or more steps in the assembly procedure of components in this portion of the manual as indicated at appropriate locations by the terminology "See Caution on page l of this section.".
Page 268 5-2 BRAKES GENERAL DESCRIPTION All vehicles are equipped with a dual hydraulic brake controlled by the front booster and rear by the rear system. booster). The split system consists basically of two separate brake systems. When a failure is encountered on either, the COMBINATION VALVE other is adequate to stop the vehicle.
Page 269 BRAKES P105 ( 42) P300 ( 32) C-K MODELS P300 ( 42) WITH RPO H22/H23 G MODELS P MODELS Fig. 1-Master Cylinder Mountings- Typical LIGHT DUTY TRUCK SERVICE MANUAL...
Page 270 5 -4 BRAKES Fig. 3--Rear Drum Brake Fig. 2--Front Disc Brake THEORY OF OPERATION Brakes are simply a means of applying friction to either The basic hydraulic brake system consists of (1) a master stop, slow down or hold an element. Brakes accomplish cylinder, in which the hydraulic pressure is developed, their job by converting motion energy, or kinetic energy, ) a cylinder at each wheel, where hydraulic pressure is...
Page 271 BRAKES is pushed forward. The fluid in the master cylinder, and This is the principle that enables us to incorporate a very the entire system, being incompressible, transmits the desirable feature in the brake system - we can vary the force exerted by the master cylinder piston to all the braking power to the wheels by changing the wheel inner surfaces of the system.
Page 272 5-6 BRAKES COVER RETAINING BAIL RUBBER DIAPHRAM RESERVOIR COVER Fig. 6--Master Cylinder u q l j q l f=£. PRIMARY SECONDARY PISTON PISTON ^vTT ®. A fro n tA brakesv Fig. 7- Rear Line Failure Fig. 8 -Front Line Failure sufficient hydraulic pressure will be generated to operate Front Line Failure (Fig.
Page 273 BRAKES added safety feature, a warning light has been Metering Valve incorporated into the brake system. The dash-mounted The Metering Valve "holds-off" front disc braking until warning light will come on when the brakes are applied the shoes of the rear drum brake contacts the drum. under a condition of partial failure.
Page 274 5 -8 BRAKES SWITCH TERMINAL SWITCH PIN ,REAR INLET PORT PROPORTIONER PISTON FRONT INLET PORT-^ SWITCH PISTON VALVE STEM DETENT FRONT OUTLET STOP PLATE PORT BOOT PROPORTIONING NUT' DIAPHRAGM REAR OUTLET PORT 'METERING VALVE SEAL FRONT OUTLET PORT METERING VALVE STEM Fig.
Page 275 BRAKES FROM MASTER CYLINDER REAR OUTLET Fig. 13--Hold-Off and Blend Pressure the instrument panel (fig. 18). When the brake pedal is depressed, the switch plunger (which is spring loaded), follows the brake pedal arm downward until the switch is Fig. 14 -Rear System Failure in the "O N "...
Page 276 5 -1 0 BRAKES of the brakes. Wear in the pedal linkage, pivot pins, or bushings, can cause loss of pedal or frequent need for brake adjustment. Pedal free play is the free travel of the pedal before any movement of the master cylinder piston occurs.
Page 277 BRAKES 5-11 springs retract all brake shoes and the connecting links piston which is transmitted to the inner brake shoe and push the wheel cylinder pistons inward, forcing fluid lining assembly and the inner surface of the disc. This back to the master cylinder. With the piston bearing tends to pull the caliper assembly inboard, sliding on the against the retaining ring and the lips of the primary four rubber bushings.
Page 278 5 -1 2 BRAKES there is not a condition of pedal travel increase with line pressure. The shoe, being at zero clearance, also respect to the front brake as the linings wear (fig. "wipes" the disc free of any foreign matter. Disc brakes also have good fade resistance with fast recovery.
Page 279 BRAKES 5-13 The anchor pin is the upper pivot point of the brake springs which are used later to return the shoes to the shoes. It is located above the wheel cylinder, and is rest position). secured to the top of the flange plate. When the shoes expand outward, they contact the drum and tend to rotate with the drum.
Page 280 5 -1 4 BRAKES slight amount of movement is not enough to cause the actuating lever to advance the star wheel. Over-Ride Mechanism (Fig. 27) All of the standard equipment self-adjusting mechanisms contain a built-in safety device known as the "over-ride pivot plate and spring".
Page 281 BRAKES 5-15 STOP TANG SEATED ON SHOE Fig. 27 Override Component Operation necessity of preventing star wheel "back-off" during the Fig. 28-Actuating Lever Stop Tang maximum self-energizing condition. To do this, a "stop tang" extends down from the under side of the actuating Parking Brake Activating Mechanism The activating mechanism for the parking brake consists lever to contact the secondary shoe (fig.
Page 282 5 -1 6 BRAKES is worn to within 1/32" of the shoe or rivet whichever is in the same manner as the bleeding operation except applicable. that bleeder valve is opened turns and the fluid is forced through the lines and bleeder valves until it emerges clear in color.
Page 283 BRAKES 5-17 Fig. 29-B rake Bleeder J-23518 and J-23709 Fig. 3 0 -Bleeding Brakes with Tool J 21472 G Model Shown cloth below the cylinder to absorb any fluid (fig. 29). Be sure to retorque the mounting spillage as the cover is removed. bolt after removing Tool J-23709.
Page 284 5 -1 8 BRAKES return slowly to the released position. Repeat Step 5 until expelled brake fluid flows in a solid stream without the presence of air bubbles, then close the bleeder valve tightly. NOTE: To assist the bleeding operation a rawhide mallet may be used to tap the caliper while fluid is flowing.
Page 285 BRAKES 5 -1 9 BRAKE LINE FUEL LINE TO MASTER CYLINDER FRONT BRAKE HOSE REAR BRAKE HOSE CO M BINATION VALVE AXLE Fig. 34-Brake Line Retainers- Typical Removal 5. Bleed brakes as outlined in this section. 1. Clean all dirt and foreign material away from both hose fitting ends.
Page 286 5 -2 0 BRAKES Safety steel tubing must be double-lap flared at the ends The following procedure should be followed in making in order to produce a strong leak-proof joint. up hydraulic brake lines. Brake Tube Flaring Tool J-2185-45° is used to form the double lap flare.
Page 287 5-21 BRAKES LATCH PLATE RAM GUIDE UPSET FLARE PUNCH DIE BLOCK\ TUBE PLATE Fig. 38--Flaring O peration DRUM BRAKE ADJUSTMENT Service Brake Although the brakes are self adjusting a preliminary or initial adjustment may be necessary after the brakes have been relined or replaced, or whenever the length of the adjusting screw has been changed.
Page 288 5 -2 2 BRAKES push rod. Power brake units incorporate a two-piece removed, with the drun locating tang i n l i n e push rod. Ordinarily there would be no reason to change with the locating hole i n he axle shaft flange.
Page 289 BRAKES 5 -2 3 parking brake is mounted on the propeller shaft) serve a . Fully release parking brake and rotate rear wheels. No drag should be present. dual purpose in that they are utilized both as a hydraulically operated service brake and also as a 7.
Page 290 5 - 2 4 BRAKES C O M P O N E N T REPLACEMENT A N D REPAIRS 1. Raise the vehicle on hoist. SHOES AND LININGS—REAR DRUM 2. Loosen check nuts at forward end of parking brake BRAKES (Fig. 44) equalizer sufficiently to remove all tension from NOTE: If brake drums are worn severely, it brake cable.
Page 291 BRAKES 5 -2 5 2. Carefully pull lower edges of wheel cylinder boots away from cylinders and note whether interior is wet with brake fluid. Excessive fluid at this point indicates leakage past piston cups requiring overhaul of wheel cylinder. NOTE: A slight amount of fluid is nearly always present and acts as lubricant for the piston.
Page 292 5 -2 6 BRAKES 4. Before installation, make certain the adjusting anchor pin stud with the regular spring hook screw is clean and lubricated properly. t o o l . Fasten the wire lin k t o the actuator assembly f i r s t , and then place over the anchor CAUTION: Loose adjustment may occur from pin stud by hand while holding the adjuster...
Page 293 BRAKES 5-27 surface of shoe rim and file off any burrs or high leaking fluid. Wheel cylinders having torn, cut, or heat- spots. cracked boots should be completely overhauled. 2. Use released brake lining (or equivalent) and the rivets included in lining package which are of the Wheel Cylinder Repair correct size.
Page 294 5 -2 8 BRAKES A cracked drum is unsafe for WARNING: PUSH ROD AN D BOOT further service and must be replaced. Do not PISTON attempt to weld a cracked drum. CUP RETURN SPRING WITH EXPANDERS Smooth up any slight scores by polishing with fine emery cloth.
Page 295 BRAKES 5 -2 9 difference between these 4 readings must not exceed wheels are removed. Check both ends of the outboard .006. shoe by looking in at each end of the caliper. This is the point at which the highest rate of wear normally occurs. At the same time, check the lining thickness on the Cleaning inboard shoe by looking down through the inspection...
Page 296 5 -3 0 BRAKES Installation If original shoes are being CAUTION: r e i n s t a l l e d , they must be installed i n original positions (as marked at removal). 1. Lubricate new sleeves, new rubber bushings, the bushing grooves and the end of the mounting bolts using Delco Silicone Lube #5459912 or equivalent (fig.
Page 297 BRAKES 5-31 no clearance between the tab at the bottom of the 11. Torque the mounting bolts to 35 ft. lbs. outboard shoe and the caliper abutment. CAUTION: See "Caution" on Page 1 of t h i s . Position the caliper over the brake disc, lining up s e c t i o n .
Page 298 5 -3 2 BRAKES Fig. 60--Caliper Explode brake shoes from the caliper. Removal CAUTION: CAUTION: Clean d i r t from hose t o caliper Mark disc pad locations i f pads are connection before proceeding with removal. t o be r e i n s t a l l e d . Disassembly 1.
Page 299 BRAKES 5 -3 3 primary sealing surface i n the caliper assembly. I t i s manufactured and plated t o close t olerances. Refinishing by any means or the use BRAKE FLUID INLET HOLE of any abrasive i s not an acceptable practice. 4.
Page 300 5 -3 4 BRAKES variation, flatness and parallelism are out of specifica Installation tion. Scoring of the brake disc surfaces not exceeding NOTE: Installation of the caliper and .015 inch in depth, which may result from normal use, mounting parts (rubber bushings, sleeves, is not detrimental to brake operation.
Page 301 BRAKES 5 -3 5 M U ST C IR C U M F E R E N T IA L (D IR EC TIO N A L) The disc in Figure 65 has a preferred non- directional finish that is achieved with a flat sanding disc.
Page 302 5 -3 6 BRAKES 4. Connect the brake lines to the master cylinder. See "Caution" on page 1 of t h i s CAUTIO N: s e c t i o n . 5. Fill the master cylinder reservoirs to the levels shown in Figure 31.
Page 303 BRAKES 5-37 outlet holes are up. Enlarge the outlet holes in the brake unit is allowed to go beyond the desired the tube seats using a 13/64" drill. Tape a 1/4" overhaul period. - 20 thread in these holes. Place a heavy washer over the outlet on the master cylinder and Assembly thread a 1/4"...
Page 304 5 -3 8 BRAKES bore so that the spring will seat in against the 4. Use snap ring pliers and remove retainer ring from closed end of the bore. Using a small wooden rod to groove in end of cylinder bore. push the secondary piston to seat.
Page 305 BRAKES 5 -3 9 1 Primary Piston Seal Cup 10 Tube Seat 16 Stop Bolt 2 Primary Piston 11 Secondary Piston Return 17 Primary Return Spring 3 Cover Seal Spring Retainer 4 Reservoir Cover 12 Secondary Piston Pressure 18 Primary Return Spring 5 Gasket 19 Prim ary Piston Stop Pin 6 Cover Bolt...
Page 306 5 -4 0 BRAKES position (not allowed to close). This can be replacement cylinder are recommended for accomplished by installing Tool J-23709 this operation. under the mounting bolt and depressing the 2. Clamp the master cylinder in a bench vise with the pin in the end of the valve.
Page 307 BRAKES 5-41 boosters have an electrical switch that senses pedal Brake Warning Light Checking travel. This switch will illuminate the lamp on the 1. Set parking brake and turn the ignition key to instrument panel whenever the brake pedal is in excess "ON".
Page 308 5 -4 2 BRAKES with the clutch pedal (except automatic I f Switch Circuit is Closed transmission), necessitating the removal of a. Rotate switch bracket rearward until switch "just the clutch pedal before removing the brake opens" (light off). pedal. b.
Page 309 BRAKES 5 -4 3 V I E W C-K MODELS POOO (42) MODELS v i e w G MODELS P300 (32) MODELS Fig. 76-Parking Brake Assembly-Typical 7. Lift the brake shoes and linings with the adjusting PARKING BRAKE CABLES nut and bolt and connecting spring off the flange Refer to Figure 77 for routing of cables.
Page 310 5 -4 4 BRAKES C MODELS G MODELS P MODELS Fig. 77-Parking Brake System LIGHT DUTY TRUCK SERVICE MANUAL...
Page 311 BRAKES 5-45 RETURN SPRINGS W A V E WASHER BRAKE LEVER HOLD D O W N DRUM HOLD D O W N WASHER. SPRING , CUP BACKING BRAKE PLATE CABLE Fig. 7 8 -Internal Expanding Brake Components 5. Install lever on cable by compressing spring and Inspection inserting cable in channel of lever.
Page 312 5 -4 6 BRAKES 3. Using Tool J-22348, remove the brake shoe pull 12. Place guide plate on anchor pin. back springs (fig. 80). 13. Install pull back springs. 4. Loosen the actuating lever cam cap screw and while 14. Remove the "knock out" plug (if necessary) and holding the star wheel end of the actuating lever install a new metal plug in the brake drum past the star wheel, remove the cap screw and cam.
Page 313 BRAKES 5 -4 7 Fig. 81-Removing Hold Down Pins Using J-22348 away from cylinders. If brake fluid flows out, overhaul of the wheel cylinders is necessary. Fig. 82-Brake Shoe and Self Adjuster Assembly NOTE: A slight amount of fluid is nearly always present and acts as a lubricant for the piston.
Page 314 5 -4 8 BRAKES ACTUATING LEVER---------► TOP VIEW ACTUATING LEVER END VIEW Fig. 84 -Positioning Actuator Lever the edge of the flange plate at the points shown in Figure 83. To center the shoes, tap the upper or lower end of the shoes with a plastic mallet until the distances at each end become equal.
Page 315 BRAKES 5 -4 9 check for leakage or the presence of air in a PRELIMINARY CHECKS non-vacuum powered brake system. External Conditions That Affect Performance d. Depress the brake pedal and start the engine. If In addition to previously mentioned conditions, the the vacuum system is operating, the brake pedal following external conditions may affect brake perform...
Page 316 5 -5 0 BRAKES the vehicle to a complete stop each time. Do not repeat Make three hard stops (just short of skid) from 60 MPH at 1/2 mile increments or just as fast as possible. Check stops within two miles of each other to avoid high brake temperatures.
Page 317 BRAKES 5-51 DIAGNOSIS—DRUM BRAKES LOW PEDAL OR PEDAL GOES TO TOE BOARD Probable Cause Remedy Excessive clearance between l i n i n g s and drum. A djust brakes. 2. Automatic a d ju s te rs not working. 2.
Page 318 5 -5 2 BRAKES DIAGNOSIS—DRUM BRAKES EXCESSIVE PEDAL PRESSURE REQUIRED TO STOP VEHICLE (CONT.) Probable Cause Remedy 7. Sand surface o f l i n i n g s . 7. Glazed 1in in g s. 8. Bellmouthed, barrel-shaped or scored drums. 8.
Page 319 BRAKES 5 -5 3 DIAGNOSIS—DRUM BRAKES ‘ BRAKES FADE Probable Cause Remedy 1. I n c o r r e c t l i n i n g . 1. Replace w ith new l i n i n g . 2.
Page 320 5 -5 4 BRAKES DIAGNOSIS—DRUM BRAKES REAR BRAKES DRAG Remedy Probable Cause 1. Maladjustment. 1. Adjust brake shoes and parking brake mechanism. 2. Parking brake cables frozen . 2. Lu bricate w ith Delco Brake Lube #5450032 (or e q u i v a le n t ) . V E H IC LE P U LLS TO ONE SID E Probable Cause Remedy...
Page 321 BRAKES 5 -5 5 DIAGNOSIS—DRUM BRAKES ONE WHEEL LOCKS Probable Cause Remedy 1. Gummy 1in in g . 1. Replace the l i n i n g s . 2. T ir e tread s l i c k . 2.
Page 322 5 -5 6 BRAKES DIAGNOSIS—DRUM BRAKES BRAKES CHATTER Probable Cause Remedy 1. I n c o rr e c t l i n i n g to drum cle arance. 1,. Readjust to recommended cle arances. 2. Loose fla n g e p la t e . 2,.
Page 323 BRAKES 5 -5 7 DIAGNOSIS—DRUM BRAKES G R IN D IN G NOISE Probable Cause Rem edy 1. Shoe h i t s drum. Switch drums or grin d drums. 2. Bent shoe web. 2. S tra ig h te n . 3.
Page 324 5 -5 8 BRAKES DIAGNOSIS—DISC BRAKES BRAKE ROUGHNESS, ETC. (C O N T .) Probable Cause Remedy 4. Rear drums o u t-o f- ro u n d . 4. Check runout and i f not w i t h i n s p e c i f i c a t i o n s , t u r n the drums.
Page 325 BRAKES 5 -5 9 DIAGNOSIS—DISC BRAKES DRAGGING BRAKES (CONT.) Probable Cause Remedy 3. I n c o rr e c t parking brake adjustment on rea r brakes. 3. Check and r e a d ju s t to c o r r e c t s p e c i f i c a t i o n s . 4.
Page 326 5 -6 0 BRAKES POWER BRAKES INDEX General Description................5-60 Theory of Operation................. 5-60 Maintenance and Adjustments............5-66 Inspection.................... 5-66 Lubrication..................5-66 Bleeding....................5-66 Air Cleaner Service................. 5-66 Component Part Replacement............5-66 Power Brake U nit................5-66 Diagnosis....................5-67 GENERAL DESCRIPTION less pedal effort than is required with the conventional The Power brake Unit is a self-contained hydraulic and vacuum unit, utilizing manifold vacuum and atmospheric...
Page 327 BRAKES 5-61 RESERVOIR COVER FRONT SHELL REAR SHELL POWER PISTON DIAPHRAGM FLUID RESERVOIRS REACTION RETAINER POWER PISTON INSERT REACTION LEVER REACTION SPRING FLOATING CONTROL VALVE PUSH ROD AIR FILTER SILENCER FLOATING PISTON STOP BOLT FLOATING PISTON ASSEMBLY AIR VALVE REACTION PLATE POWER PISTON RETURN SPRING MASTER CYLINDER PUSH ROD SUPPORT PLATE...
Page 328 5 -6 2 BRAKES Fig. 8 7 -Typical Circuit - Released piston. The floating control valve assembly is held In this position there is vacuum on both sides of the against the air valve seat by the floating control valve power piston, and the power piston is held against the spring.
Page 329 BRAKES 5 -6 3 VACUUM REACTION PLATE FLOATING CONTROL VALVE AIR VALVE UNSEATED AIR VALVE REACTION LEVERS ATMOSPHERIC PRESSURE Fig. 88-Typical Power Unit - Applying power piston, and air under atmospheric pressure enters APPLYING (Figs. 88 and 89) through the air filter and travels past the seat of the air As the pedal is depressed, the valve operating rod (push valve and through a passage into the housing at the rear rod) carries the air valve away from the floating control...
Page 330 5 -6 4 BRAKES Fig. 8 9 -Typical Circuit - Applying As the power piston travels forward, the master cylinder the master cylinder piston, the hydraulic reaction plate is piston rod carries the master cylinder primary piston moved off its seat on the power piston and presses against the reaction levers.
Page 331 BRAKES 5 -6 5 VACUUM REACTION PLATE FLOATING CONTROL VALVE AIR VALVE SEATED AIR VALVE REACTION LEVERS ATMOSPHERIC PRESSURE Fig. 90--Typical Power Unit - Holding Since both sides of the power piston are now under HOLDING (Figs. 90 and 91) vacuum, the power piston return spring will return the When the desired pedal pressure is reached, the power piston to its released position against the rear housing.
Page 332 5 66 BRAKES Fig. 91--Typical Circuit • Holding the hydraulic reaction plate. Since the hydraulic reaction VACUUM FAILURE plate is fastened to the master cylinder piston rod, it In case of vacuum source interruption, the brake unit forces the piston rod against the master cylinder primary operates in the following manner: piston, which builds up the hydraulic line pressure.
Page 333 BRAKES 5 -6 7 running and the vacuum reserve should be reduced to LUBRICATION zero by applying the brake several times before starting The power brake unit is lubricated at assembly and the bleeding procedure. needs no further lubrication other than maintaining normal reservoir fluid level.
Page 334 5 -6 8 BRAKES DIAGNOSIS NOTE The same types o f brake troub le s are encountered w ith power brakes as w ith standard brakes. Before check ing the power brake system f o r source o f t r o u b le , r e f e r to tro u b le diagnosis o f standard h y d ra u lic brakes in t h is manual.
Page 335 BRAKES 5 -6 9 DIAGNOSIS—POWER HYDRAULIC BRAKES SLOW BRAKE PEDAL RETURN Probable Cause Remedy 1. Excessive seal f r i c t i o n in power u n i t . Overhaul u n i t as o u t lin e d in the "Overhaul" Manual. 2.
Page 336 5 -7 0 BRAKES SPECIAL TOOLS G U U 1. J-2185 Flaring Tool 5. J-21472 Bleeder Wrench 2. J-8000 Tubing Cutter 6. J-22904 Dust Boot Installer 3. J-8049 or J-22348 Spring Remover 7. J-23518 Bleeder Adapter 4. J-21177 Drum/Shoe Gage 8.
Page 337 SECTION 6 ENGINE CONTENTS OF THIS SECTION Engine Tune-Up..............6-1 Engine Mechanical (V )............ 6-44 Theory of Operation............6-14 Diagnosis................. 6-68 Engine Mechanical (In Line)......... 6-19 Special Tools................. 6-73 ENGINE TUNE-UP INDEX Choke Adjustment............. 6-7 General Description............Mechanical Checks and Adjustments......Instrument Check-Out.............
Page 338 6-2 ENGINE enough force to remove the boot. Do not pull on plug with the compression check, see “Cylinder Balance Test” under “Additional Checks and wire. Adjustments” in this section. TEST COMPRESSION (FIG. 1) The compression check is important because an engine SERVICE AND INSTALL SPARK with low or uneven compression cannot be tuned PLUGS (FIG.
Page 339 EN G IN E remove all roughness nor dress the point surfaces down smooth. Merely remove scale or dirt. • Clean cam lobe with cleaning solvent and rotate cam lubricator wick 180°. NOTE: Where prematurely burned or badly pitted points are encountered, the ignition system and engine should be checked to determine the cause of trouble so that it can be eliminated.
Page 340 6 -4 ENGINE C A R B O N L PATH C R A C K C A R B O N PATH ERODED TOWER INSPECTION OF DISTRIBUTOR CLEANING & INSPECTION OF CLEANING & INSPECTION OF CAP TOWERS OUTSIDE OF DISTRIBUTOR CAP INSIDE OF DISTRIBUTOR CAP REPLACING DISTRIBUTOR ROTOR TIP...
Page 341 EN G IN E PROPER LATERAL LATERAL ALIGNMENT MISALIGNMENT WEIGHT ROTOR ASSEMBLY -' 1 R.F.I. SHIELD . 1 1 ' " J CIRCUIT BREAKER CORRECT LATERAL MISALIGNMENT BY PLATE ASSEMBLY BENDING FIXED CONTACT SUPPORT NEVER BEND BREAKER LEVER PERMANENT Fig. 6—Point Alignment LUBRICATION RESERVOIR VACUUM...
Page 342 6 -6 ENGINE Fig. 9—Manifold Heat Control Valve (L6) Fig. 8—Checking Fan Belt Tension detect internal or external leaks within the cooling system. SERVICE CRANKCASE VENTILATION (FIG. 1 1 ) All engines have a “Closed Positive” ventilation system utilizing manifold vacuum to draw fumes and contami nating vapors into the combustion chamber where they are burned.
Page 343 ENGINE 6-7 carburetor or distributor designed for different CHOKE ADJUSTMENT Inspect choke valve, choke rod, choke coil and housing applications. for proper alignment, bends and binding — make necessary corrections to assure proper choke operation; then adjust choke as outlined in Section Fig.
Page 344 6-8 ENGINE C R A N K C A S E V E N T IL A T IO N FILTER Fig. 13—Crankcase Ventilation Filter INSTRUMENT CHECK-OUT check the INSTRUMENT HOOK-UP Connect vacuum gauge, dwell meter, tachometer and distributor as outlined in Section 6Y. timing light as recommended by the manufacturer of the equipment being used.
Page 345 ENGINE 6-9 W INDOW "H E X ” TYPE W RENCH SCREW Fig. 14—Setting Point Dwell (Typical V8) ADJUST IDLE SPEED (FIG. 16) Emission system requirements necessitate the division of the Series 10-30 trucks into two groups as follows: a. Light Duty Emission Vehicles - Includes all 10 Fig.
Page 346 6 -1 0 ENGINE SINGLE-BARREL TW O -B AR REL FOUR-BARREL IDLE M IXTURE SC REW IDLE MIXTURE SC REW S IDLE M IXTURE SC RE W S CEC S O L E N O ID IDLE SPEED (S O L E N O ID ) SC REW IDLE SPEED (S O L E N O ID ) SC R E W Fig.
Page 347 EN G IN E * 6-11 screw to obtain 1600 rpm with screw on top step of fast 700 rpm on all Heavy Duty vehicles - automatic idle cam. transmission in “Park” ; manuaPMransmission in neutral. On Light-Duty vehicles with manual transmission, adjust 6V 00 rpm on Light-Duty vehicles with automatic fast idle screw to obtain 1300 rpm with screw on top step transmission (in Drive).
Page 348 6 -1 2 ENQINE • Secondary Resistance Ignition Switch With voltmeter connected as described for the Cranking • Ignitioft’oulput and secondary leakage Voltage Test, turn ignition switch to ON. Voltage should drop to 5 to 7 volts as current is now passing through Cranking Voltage (Fig.
Page 349 EN G IN E 6 -1 3 occurring in distributor cap or between spark plug rocker arm cover rearward with palm of hand cables concerned. or a rubber m allet. • If meter reads off scale to left, the coil polarity is 2.
Page 350 6 -1 4 ENGINE Fig. 22—Valve Adjustment (V8 Engine) Fig. 21—Valve Adjustment (L6 Engine) are again in alignment. This is number firing with fingers as the nut is tightened (fig. position. With the engine in this position the When push rod does not readily move in following valve may be adjusted.
Page 351 E N G IN E 6 -1 5 Fig. ID —Sectional View of Eight-Cylinder Engine LIGHT DUTY TRUCK SERVICE MANUAL...
Page 352 6-16 ENGINE Fig. 2D—Sectional View of Six-Cylinder Engine down. This downward motion of the piston is Intake Stroke transmitted through the connecting rod and is converted The intake valve is opened as the piston moves down in to rotary motion by the crankshaft. Both the intake and the cylinder (Fig.
Page 353 EN G IN E 6 -1 7 Fig. 4D—Piston Compression Stroke Fig. 3D—Piston Intake Stroke combustion process is still occurring and this continues to pressure. Actually, about 75 per cent of the mixture in raise the temperature of the gases, expanding them and the cylinder is composed of nitrogen gas that does not maintaining a continuous pressure on the piston as it burn but expands when heated by the burning of the...
Page 354 6 -1 8 ENGINE Fig. 6D—Piston Exhaust Stroke Fig. 5D—Piston Power Stroke compression pressure (input) means at least three times TOP DEAD CENTER as great an increase in combustion pressure (output). INTAKE VALVE- EXHAUST VALVE OPENS CLOSES Valve Timing As in most 4-stroke cycle engines, the intake valve begins to open before the piston reaches the top, and the exhaust valve remains open until after top dead center.
Page 355: Table Of Contents
EN G IN E 6 -1 9 valve still open, the cylinder continues to empty itself because of this momentum. On the compression stroke, the intake valve stays open past bottom center because incoming gases will continue to pack their way in for a short time after the piston reverses direction, due to their momentum.
Page 356: General Description
6 - 2 0 ENGINE Measuring Lobe Lift ............6-33 Removal ................6-35 Removal ................6-34 Installation ................6-35 Installation ................6-34 Engine Mounts...............6-36 Timing Gears ..............6-35 Checking Engine Mounts ..........6-36 Replacement ..............6-35 Replacement (Front) ............6-36 Flywheel ................
Page 357 E N G IN E 6-21 Fig. 1 L —Six-C ylinder Engine 9. Remove engine from vehicle as follows: b. Remove bolts attaching the clutch housing to engine block then remove transmission and CAUTION: Check often during engine removal clutch housing as a unit. t o be sure a l l necessary disconnects have been NOTE: Support the transmission as the last made.
Page 358: Removal (G Series)
6 -2 2 ENGINE ON ALL SERIES EXCEPT CS 10-20-30: • Fuel line (from tank) at fuel pump. • Remove clutch housing. • Engine ground strap(s). • Steering idler arm at frame. • Loosen clutch mounting bolts a turn at a time (to prevent distortion of clutch cover) until the •...
Page 359 EN G IN E 6 -2 3 15. Disconnect shock absorbers at frame or at lower control arm attachment and position shocks up and rearward. 16. Remove propeller shaft as outlined in Section 4 - install plug in transmission extension. 17.
Page 360: Installation (C, K And P Series)
6 -2 4 ENGINE • Install synchromesh transmission and clutch (if • Power steering pump (as required). so equipped). • Vacuum lines at engine (as required). a. Install the clutch assembly on flywheel as • Oil pressure gauge line (as required). outlined in Section 7.
Page 361: Manifold Assembly
E N G IN E 6-25 16. Remove wood block placed between crossmember engine and transmission assembly and install and oil pan. flywheel to converter bolts. 17. Lower vehicle on hoist. c. Install converter housing underpan and starter. 18. Connect accelerator linkage at dash panel mounted d.
Page 362: Rocker Arm Cover
6 -2 6 ENGINE manifold has distorted to a point where it will not and push rods in a rack so that they may be seat properly. If a good exhaust seal is to be reinstalled in the same location. expected, the exhaust manifold must be replaced.
Page 363: Locating Noisy Lifters
EN G IN E 6-27 c. Improper adjustment. 3. General Noise Throughout the Valve Train — This will, in most cases, be caused by either insufficient oil supply or improper adjustment. 4. Intermittent Clicking — Probable causes are: a. A microscopic piece of dirt momentarily caught between ball seat and check valve ball.
Page 364: Cylinder Head Assemblies
6 -2 8 ENGINE remove the valve locks, valve cap, valve shield and gasket. Place cylinder head on two blocks of wood to prevent damage. valve spring and damper (fig. 7L). 5. Remove the valve stem oil seal. Installation . To replace, set the valve spring and damper, valve The gasket surfaces on both the CAUTIO N: shield and valve cap in place.
Page 365: Oil Pump
EN GINE 6-29 Fig. 8L—Engine Blocked for Oil Pan Removal 3. Install new front seal on crankcase front cover pressing, tips into holes provided in cover. 4. Install new side gaskets on cylinder block (fig. 9L). NOTE: DO NOT USE SEALER. 5.
Page 366: Torsional Damper
6 30 ENGINE . Coat seal lips and seal bead with light engine oil — 13. Install the rear main bearing cap (with new seal) keep oil off seal mating ends. and torque to specifications. 7. Position tip of tool between crankshaft and seal seat in cylinder case.
Page 367: Crankcase Front Cover
E N G IN E 6-31 Fig. 15L—Removing Torsional Damper Fig. 13L—Crankshaft Oil Seal (Rear Main) CAUTION: I n s ta ll t o ol i n crankshaft so that a t l e a s t 1/2" of thread engagement i s obtained. b.
Page 368: Oil Seal (Front Cover)
6 -3 2 ENGINE Fig. 18L—Cutting Tabs on Oil Pan Front Seal Fig. 17L—installing Torsional Damper (Pull on Type) 2. Cut tabs from the new oil pan front seal (fig. 19L) use a sharp instrument to ensure a clean cut. 3.
Page 369: Camshaft
EN G IN E 6-33 2. Install new seal so that open end of the seal is Camshaft toward the inside of cover, and drive it into position with Tool J-23042 (fig. 22L). Measuring Lobe Lift NOTE: Procedure is similar to that used for checking valve timing.
Page 370 6 -3 4 ENGINE crankshaft slowly, or attach an auxiliary starter switch and “bump” the engine over, until the push rod is in the fully raised position. Whenever the engine i s cranked CAUTIO N: remotely at the s t a r t e r , with a special jumper cable or other means, the distributor primary lead must be disconnected from the negative post on the c o i l .
Page 371 E N G IN E 6 - 3 5 Fig. 29L—Installing Crankshaft Gear 8. Install crankcase front cover as outlined. 9. Install valve lifters as outlined. Timing Gears Replacement With camshaft removed, crankshaft gear may be removed using Tool J-8105 (fig. 28L). To install crankshaft gear use Tool J-5590 (fig.
Page 372 6 3 6 E N G IN E holes with Tool J-22808-2 and then finish reaming a. Disconnect clutch rod at outboard lever on them with Tool J-22808-1 (fig. 31L). clutch cross shaft. 5. Install oversize dowel pins flush with flywheel b.
Page 373 E N G IN E 6 - 3 7 6. Position support crossmember to cross rail, install underbody cross rail and withdraw support from bolts then loosely install crossmember-to-mount vehicle. retaining bolts. 4. Remove bolts securing mount to transmission extension. 7.
Page 374 6 3 8 E N G IN E 250 CU. IN. ENGINE 4 i LEFT & RIGHT MOUNT & FRAME BRACKET 292 CU. IN. ENGINE LEFT MOUNT & FRAME BRACKEET ENGINE BRACKET ALL P SERIES WITH L-6 ENGINE 292 CU. IN. ENGINE RIGHT FRAME BRACKET &...
Page 375 E N G IN E 6 - 3 9 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 376 6 - 4 0 E N G IN E LIGHT DUTY TRUCK SERVICE MANUAL...
Page 377 E N G IN E 6-41 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 378 Fig. 37L—K Series Engine Front Mount...
Page 379 E N G I N E 6 - 4 3 REAR MOUNT FRONT MOUNT Fig. 38L—G Series Engine Mounts LIGHT DUTY TRUCK SERVICE MANUAL...
Page 380 ENGINE 6-44 ENGINE MECHANICAL V-8 ENGINES INDEX Removal................6-53 General Description............6-44 Installation................. 6-53 Component Replacement and Adjustment....6-44 Oil Pump................6-54 Engine Assembly..............6-44 Removal................6-54 Removal................6-44 Installation................. 6-54 Installation................. 6-47 Oil Seal (Rear M ain)............6-54 Intake M anifold..............6-49 Replacement..............
Page 381 ENGIN E 6-45 4. Disconnect wires at: • On vehicles with automatic or four speed transmissions, remove rear mount crossmember. • TCS Solenoid • Raise engine and transmission assembly and pul! • Starter Solenoid forward until removed. • Delcotron ON KE 10-20 SERIES: •...
Page 382 6 - 4 6 E N G IN E G Series front crossmember-to-frame attaching bolts (Fig. 1. Remove engine cover and position it out of way. 2V). 2. Disconnect battery ground cable at engine block 19. Remove the four (2 on each side) frame-to-upper and at battery.
Page 383 E N G I N E 6 4 7 24. Remove the four (2 on each side) remaining 29. Remove synchromesh transmission and clutch (if so suspension-to-frame (outside) retaining bolts (Fig. equipped). 3V). a. Remove clutch housing rear cover bolts. 25.
Page 384 6 - 4 8 E N G IN E ON CE 10-20-30 SERIES: • Lower engine and transmission assembly and push rearward until engine mounts line up. • On vehicles with automatic or four speed transmissions, install rear mount crossmember. •...
Page 385 E N G IN E 6 - 4 9 b. Install clutch housing rear cover and starter. • Steering idler arm at frame. c. Install the transmission and clutch housing as • Steering pitman arm at steering gear - torque outlined in Section 7.
Page 386 6 - 5 0 E N G IN E • Spark advance hose and governor line (if so 3. Remove distributor cap and mark rotor position equipped) at distributor. with chalk, then remove distributor. • Crankcase ventilation lines (as required). 4.
Page 387 E N G I N E 6-51 5. Remove rocker arm cover. Exhaust — 1, 3, 4, 8 Intake — 1, 2, 5, 7 Do not pry rocker arm cover loose. CAUTION: Gaskets adhering to cylinder head and rocker c. Back out adjusting nut until lash is felt at the arm cover may be sheared by bumping end of push rod then turn in adjusting nut until all lash rocker arm cover rearward with palm o f hand...
Page 388 6 - 5 2 E N G IN E will, in most cases, be caused by either insufficient oil supply or improper adjustment. 4. Intermittent Clicking—Probable causes are: a. A microscopic piece of dirt momentarily caught between ball seat and check valve ball. b.
Page 389 E N G IN E 6 - 5 3 J -2 3 5 9 0 FRONT Fig. 9V—Compressing Valve Spring SEAL 5. Remove cylinder head bolts, cylinder head and gasket. Place cylinder head on two blocks of wood to prevent damage. Installation CAUTION: The gasket surfaces on both the...
Page 390 6 - 5 4 E N G IN E rear seal in rear main bearing cap groove, with 1. With the oil pan and oil pump removed, remove ends butting side gaskets. Install new oil pan front the rear main bearing cap. seal in groove in crankcase front cover with ends 2.
Page 391 E N G I N E 6 - 5 5 7. Position tip of tool between crankshaft and seal seat NOTE: Tool J-23523 has holes forming two patterns. A two bolt and a three bolt pattern. in cylinder case. The holes for the two bolt pattern must be 8.
Page 392 6 - 5 6 E N G IN E APPLY SEALANT TO SHADED AREAS ONLY Fig. 16V—Removing Torsional Damper Fig. 15V—Sealing Bearing Cap Fig. 17V—Installing Torsional Damper 4. Puil the cover slightly forward only enough to permit cutting of oil pan front seal. Fig.
Page 393 E N G I N E 6 - 5 7 Fig. 19V—Oil Pan Front Seal Modification 8. Install and partially tighten the two, oil pan-to-front cover attaching screws. 9. Install the front cover-to-block attaching screws. Fig. 21V—Installing Oil Seal (Cover Removed) 10.
Page 394 6 5 8 E N G IN E J-23042 Fig. 22V—Installing Oil Seal (Cover Installed) 7. Draw camshaft sprocket onto camshaft, using the Fig. 23V—Timing Sprocket Alignment Marks three mounting bolts. Torque to specifications. 8. Lubricate timing chain with engine oil. 9.
Page 395 E N G IN E 6 - 5 9 w a s h e r (TORSIONAL DAMPER) Fig. 2 6 V —Removing Crankshaft Sprocket (Mark ! V V8) reads zero. This will be a check on the accuracy of the original indicator reading. 7.
Page 396 6 6 0 E N G IN E Checking Engine Mounts Front Mount Raise the engine to remove weight from the mounts and to place a slight tension in the rubber. Observe both mounts while raising engine. If an engine mount exhibits: a.
Page 397 E N G I N E 6-61 attaching bolts from frame outrigger and clutch sufficient clearance. Check for interference housing and remove rear mounting cushions. between rear of engine and cowl panel. 4. Remove mount-to-tfansmission bolts, then remove 4. Replace mount to engine and lower engine into mount.
Page 398 6 - 6 2 E N G IN E M A N U A L TR A N S M ISS IO N W ITH PROPELLER SHAFT PAR KING BRAKE ALL TURBO H Y D R A -M A T IC 4 0 0 (EXCEPT MOBILE H O M E CHASSIS) W ITH O U T PROPELLER SHAFT PARKING BRAKE ALL M A N U A L TRAN SM ISSIO N...
Page 399 E N G I N E 6 - 6 3 VIEW A 3 5 0 CU. IN . M O TO R H O M E CHASSIS 4 5 4 c u VIEW 4 5 4 CU VIEW ALL EXCEPT M O TO R H O M E CHASSIS 3 0 7 &...
Page 400 6 - 6 4 E N G IN E LIGHT DUTY TRUCK SERVICE MANUAL...
Page 401 E N G IN E 6 - 6 5 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 402 6 - 6 6 E N G IN E LIGHT DUTY TRUCK SERVICE MANUAL...
Page 403 E N G IN E 6 -6 7 Fig. 36V—C Series Engine Mounts LIGHT DUTY TRUCK SERVICE MANUAL...
Page 404 6-68 ENGINE DIAGNOSIS ENGINE FAILS TO START CAUSE Corroded or loose battery terminal connections Weak or faulty coil. and/or weak battery. Carburetor flooded and/or fuel level in carburetor Broken or loose ignition wires and/or faulty bowl not correct. ignition switch. Dirt and water in gas line or carburetor.
Page 405 ENGINE 6-69 ENGINE STALLS CAUSE a. Carburetor idle speed set too low and/or idle j- Distributor advance inoperative. mixture too rich or too lean. k. Exhaust system restricted. b. Carburetor needle valve and seat inoperative. Leaks in carburetor mounting gasket or intake manifold.
Page 406 6-70 ENGINE EXCESSIVE OIL CONSUMPTION DUE TO OIL ENTERING COMBUSTION CHAMBER THROUGH HEAD AREA CAUSE a. Intake valve seals damaged or missing. d. Intake manifold gasket leak in conjunction with b. Worn valve stems or guides. rocker cover gasket leak. c.
Page 407 ENGINE 6-71 NOISY VALVES CAUSE a. Incorrect valve lifter clearance. e. Worn camshaft lobes. b. Excessively worn, dirty or faulty valve lifters. f. Pulled or loose rocker arm studs. c. Worn valve guides. g. Bent push rods. d. Excessive run-out of valve seat or valve face. h.
Page 408 6-72 ENGINE TORQUE SPECIFICATIONS C Y L I N D E R H E A D T O R Q U E S E Q U E N C E S M A L L V 8 ' ' M A R K I V V 8 ' I N T A K E M A N I F O L D T O R Q U E S E Q U E N C E F R O N T “...
Page 409 ENGINE 6-73 SPECIAL TOOLS (.0 0 3 ” ) Rocker A rm Stud J-5715 J-4536 Engine L if t K it Reamer (0-200 F t. Lb.) Torque Wrench J-1264 (.01 3 ” ) J-6036 J-8058 (0-50 Ft. Lb.) J-6880 Rocker A rm Stud Installer J-5853 (0-100 in lb.) J-5802...
Page 411 E N G I N E C O O L I N G 6K-1 SECTION 6K ENGINE COOLING INDEX General Description............6K-1 Heater Core..............6K-9 Theory of Operation............6K-2 Fan Belt Adjustment............. 6K-9 Radiator C ap ..............6K-9 Maintenance and Adjustments........6K-7 Coolant Level..............
Page 412 6 K - 2 E N G IN E C O O L IN G Fig. 3—Water Pump—Typical V-8 THEORY OF OPERATION The engine cooling system is designed to maintain the coolant by-pass in the cylinder head and block. Coolant tfngine at its most efficient operating temperature at all circulation, after normal operating temperatures are engine speeds and all driving conditions.
Page 413 E N G I N E C O O L I N G 6 K -3 Fig. 4—Engine Coolant Circulation (Six-Cylinder) combustion to the coolant and then to transfer heat in COMPONENTS the coolant to air flowing passed the radiator. Water Pump Radiators are of the cross-flow type (Fig.
Page 414 6 K - 4 E N G IN E C O O L IN G develops high pressure areas in front of the wipers, thus WARM WATER the fluid is forced back into the reservoir. But as the COLD RADIATOR TRANSMISSION FROM ENGINE temperature rises the arm uncovers more of the large FILL LEVEL...
Page 415 E N G I N E C O O L I N G 6 K -5 .BALL BEARING i| S - F------ / CLUTCH PLATE WORKING CHAMBER v B 1 ' W FLUID RESERVOIR CHAMBER PUMP PLATE BIMETALLIC COIL Fig. 6—Automatic Fan Clutch ENGINE OVERHEATING A.
Page 416 6 K - 6 E N G IN E C O O L IN G between fan blades and thermometer sensor before starting engine. Position thermometer so that the thermometer sensor is centered in the space between the fan blades and radiator. This can be achieved by inserting the sensor through one of the existing holes in the fan shroud or fan guard, or by placing between the radiator and the shroud.
Page 417 E N G I N E C O O L I N G 6 K -7 ment for -20°F. protection, coolant boiling point is less System Inhibitor and Sealer or equivalent. In addition, than the temperature indicating light setting. When Cooling System Inhibitor and Sealer should be added adding solution due to loss of coolant for any reason or every fall thereafter.
Page 418 6 K - 8 E N G IN E C O O L IN G speed until engine coolant temperature reaches 180 Periodic Maintenance degrees. It is the owner’s responsibility to keep the freeze 6. Remove cover from radiator and continue to run protection at a level commensurate with the area in the engine for 20 minutes.
Page 419 E N G I N E C O O L I N G 6 K -9 4. Continue this flushing until the water from the 3. Inspect thermostat valve to make sure it is in good lead-away hose runs clear. condition.
Page 420 6 K - 1 0 E N G IN E C O O L IN G Fig. 13 —Checking Run-Out Fig. 12—Securing Fan Blade movement. This represents the total radial run-out. Mark the point on the pulley at which the highest reading is obtained.
Page 421 E N G IN E C O O L I N G 6K -1 1 1. Siphon coolant from the radiator and break loose vertical plane to prevent silicone fluid the fan pulley bolts. leakage. 4. Remove pump to cylinder block bolts and remove 2.
Page 422 6 K - 1 2 E N G IN E C O O L IN G 5. Check fan belt for excessive looseness. Once level becomes stabilized, it will not change appreciable during operation. 6. Check for punctures in radiator, ruptured or disconnected hoses, loose pressure cap or use of low 2.
Page 423 E N G IN E C O O L I N G 6 K - 1 3 Fig. 16—Overheating Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Page 424 6 K - 1 4 E N G IN E C O O L IN G Fig. 17—Coolant Loss Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Page 425 E N G I N E FUEL 6 M - 1 SECTION 6M ENGINE FUEL CONTENTS OF THIS SECTION Description................. 6M-1 Service Operations............6M-23 Theory of Operation............6M-3 Diagnosis................6M-42 Maintenance and Adjustments........6M-16 Special Tools..............6M-67 DESCRIPTION This Section of the 1973 Truck Service Manual covers the behind the fuel inlet nut to give maximum filtration of above "Contents"...
Page 426 6 M - 2 E N G IN E FUEL MODEL 2GV (2 bbl.) SAE 1-1/2 MODEL 2GV (2 bbl.) SAE 1-1/4" CARBURETOR CARBURETOR The Rochester Model 2GV 1-1/4 (small bore 2 bbl.) The Model 2G, 2GV (large bore 1-1/2”) carburetors include carburetor includes some of the following features.
Page 427: Theory Of Operation
E N G I N E FUEL 6 M - 3 lower port, the upper port bleeds air into the vacuum MODEL 4MV (4 bbl.) QUADRAJET channel and modulates the amount of vacuum signal CARBURETOR supplied by the lower E.G.R. port. In this manner, the The Model 4MV carburetor has many features including E.G.R.
Page 428: Atomization
6 M - 4 E N G IN E FUEL important applications in the transformation of liquid gasoline to a capor for use in combustion. In a carburetor (Fig. 2), gasoline is discharged into the incoming air stream as a spray and the spray is then atomized, or torn into fine droplets to form a mist.
Page 429: Metering
E N G I N E FUEL 6 M - 5 is further limited by the amount of air that the fuel vapor is absorbed by. Combustible mixtures in an engine are limited by the following proportions, or ratios, of air to gasoline: eight parts air to one part gasoline is the richest mixture that will fire regularly and a mixture of 18 1/2 parts air to one part gasoline is the leanest...
Page 430: Fuel Metering
6 M - 6 E N G IN E FUEL more convenient valve for measuring the larger pressure differences. FUEL METERING As shown in measurement of air flow with the U-tube, fluids flow when there is a difference in pressure and will always flow toward the lower pressure.
Page 431: Venturi Principle
E N G I N E FUEL 6 M - 7 pressure drop and promote atomization of the fuel. The VENTURI PRINCIPLE (FIG. 8) large venturi, cast in the carburetor bore, is called the To obtain a greater pressure drop at the tip of the nozzle primary or main venturi.
Page 432: Fuel-Air Requirements
6 M - 8 E N G IN E FUEL demand but caused by light speed variations and mixture for cylinder 4, 5, and 6 will initially travel changing engine load conditions such as a moderate towards the rear of the engine. grade.
Page 433: Cold Starts
E N G IN E FUEL 6 M - 9 ignition timing, and other engine design factors. The optimum mixture can best be determined by operating an engine on a dynamometer where power, speed, and fuel consumption may be measured over a wide range of conditions.
Page 434: Float System
6 M - 1 0 ENGINE FUEL it does so under such varied conditions that it is delivery and fuel spillage during normal car maneuver necessary to have several systems to alter its functions so ing, each of which causes excessive fuel consumption and that it can adjust to various situations.
Page 435: Idle System
E N G IN E FUEL 6 M -1 1 during the off-idle range they change to fuel mixture main nozzle with air bleeds in it. The main jet is a very feeds. accurately machined orifice, which controls the fuel flow through the main well in which the nozzle is located.
Page 436 6 M - 1 2 ENGINE FUEL Pump System (Fig. 19) TYPICAL FLOW CURVE SHOW ING When the throttle is opened rapidly, the air flow and SYSTEMS OPERATION VS. M.P.H. manifold vacuum change almost instantly. Because of the great difference in weight between air and fuel, any sudden change in throttle opening results in an immediate increase in air intake but the fuel, having V "...
Page 437: Main Metering System
E N G IN E FUEL 6 M - 1 3 M A IN W ELL A IR BLEED POWER PISTON M E T E R IN G ROD M A IN D ISC HA R G E N O Z Z L E POWER PISTON SPRING BOOST V E N T U R I...
Page 438: Power System
6 M - 1 4 ENGINE FUEL MAIN WE LL AIR BLEED POWER PISTON M A IN D ISC H A R G E D R IV E RO D N O Z Z L E BOOST V E N T U R I M E T E R IN G M A IN V E N T U R I POWER...
Page 439: Pump System
E N G IN E FUEL 6 M - 1 5 " T " D IS C H A R G E SPR IN G R E T A IN E R PUMP L E V E R PUMP P L U N G E R &...
Page 440: Choke System
6 M - 1 6 ENGINE FUEL Fig. 20--Choke System M AINTEN A NC E A N D ADJUSTMENTS some major carburetor repair or replacement which affects NOTE: Also refer to the "Emission Control the idle screw adjustment. Systems" Booklet for required maintenance and warranty information.
Page 441 E N G IN E FUEL 6 M - 1 7 clogged carburetor or fuel pump filter may restrict fuel IDLE STOP SOLENOID-The idle stop solenoid should be checked to assure that it permits the throttle flow or bypass foreign m aterial into carburetor plate to close further when the ignition switch is turned depending upon type used.
Page 442 6 M - 1 8 ENGINE FUEL 2. Rotate choke valve toward direction of closed choke Fig. 2C~Fast Idle Adjustment (Rochester 4MV) by applying force to choke coil lever. 3. Bend choke rod at point shown to give specified opening between the lower edge of choke valve (at center of valve) and inside air horn wall.
Page 443 E N G IN E FUEL 6 M - 1 9 (4MV) (2GV) 3. With the vacuum break diaphragm in the fully seated position, push the choke valve toward the closed position. 4. With the choke valve held in this position, place specified gauge between the lower edge of the choke valve and air horn wall.
Page 444 6 M - 2 0 ENGINE FUEL GAUGE BETWEEN A IR HORN WALL AN D LOWER EDGE OF CHOKE VALVE V A C U U M PLUNGER M U S T BE FULLY SEATED USE OUTSID E V A C U U M SOURCE LIGHTLY ROTATE CHOKE COIL LEVER COUNTERCLOCK W ISE UN TIL END OF ROD IS...
Page 445 E N G IN E FUEL 6 M -2 1 5. Install choke coil spring cover. . Insert coil rod into choke coil lever slot and install retaining clip. 7. Make sure that the choke valve operates freely and coil rod does not bind on choke cover from the full open to full closed position.
Page 446 6 M - 2 2 E N G IN E FUEL A IR V A LV E C O M P L E T E L Y C L O S E D B EN D R O D H E R E TO O B T A IN S P E C IF IE D C L E A R A N C E B ET W E E N R O D A N D EN D O F S L O T...
Page 447 E N G I N E FUEL 6 M - 2 3 SERVICE OPERATIONS (INCLUDING ADDITIONAL EXTERNAL SETTINGS AND ADJUSTMENTS) INDEX Carburetor Removal............6M-23 Fuel Pumps................6M-40 Special Tools..............6M-67 Accelerators and Choke Controls........6M-27 Air Cleaners..............6M-33 2. Disconnect fuel and vacuum lines from carburetor. ALL CARBURETORS 3.
Page 448 6 M - 2 4 E N G IN E FUEL TORQUE BOLTS (4) TO 14 FT. LBS. INSULATOR Fig. K 3 -C h o k e Coil R od, 4 M V R o c h e s te r to be checked.
Page 449 E N G I N E FUEL 6 M - 2 5 Fig. K 4--F uel F ilte r (P a p e r-T y p e ) (T y p ic a l) 3. Install carburetor over manifold studs or holes. Check paper element by blowing on fuel inlet end.
Page 450 6 M - 2 6 E N G IN E FUEL 5. Install bolt and tighten securely. Sticker, sometimes referred to as tuneup sticker, (also see Section , Tuneup) before proceeding: . Adjust and connect choke rod as outlined. 7. Start and warm-up the engine then check operation CAUTION: After following the below proce...
Page 451 E N G I N E FUEL 6 M - 2 7 TWO BARREL AND FOUR BARREL CAR c. Set dwell and timing and recheck low idle speed. BURETORS d. Reconnect electrical connector to the solenoid. a. Disconnect electrical connection at the end of Open the throttle momentarily and adjust the the idle stop solenoid.
Page 452 6 M - 2 8 E N G IN E FUEL SUPPORT STUD—TORQUE^ DETENT CABLE Fig. K 6 --A c c e le ra to r C o n tro ls a n d C ab le , CS a n d KS LIGHT DUTY TRUCK SERVICE MANUAL...
Page 453 E N G I N E FUEL 6 M - 2 9 CARBURETOR LEVER COTTER P IN - LOCK WASHER TORQUE AT PLAIN 120 IN. LBS. LEVER WASHER CABLE ASSEMBLY ASSEMBLY ROD ASSEMBLY CARBURETOR LEVER LEVER ASSEMBLY TORQUE AT 65 IN. LBS. PLAIN WASHER LOCK WASHER...
Page 454 6 M - 3 0 ENGINE FUEL SUPPORT TORQUE AT CARBURETOR CABLE ASSEMBLY 65 IN. LBS. LEVER SPRING LEVER ASSEMBLY X CABLE ASSEMBLY n f l 1 V IE W i n n r * £ l O ^ I^ C A R B U R E T O R BRACKET ASSEMBLY1 ( v i e w...
Page 455 E N G IN E FUEL 6 M -31 Fig. K13— Accelerator Controls, P30 (42) 454 Engine LIGHT DUTY TRUCK SERVICE MANUAL...
Page 456 6 M - 3 2 ENGINE FUEL Fig. K15—Accelerator Controls - G-Van (L-6) LIGHT DUTY TRUCK SERVICE MANUAL...
Page 457 E N G IN E FUEL 6 M - 3 3 CAUTION Care must be taken during installation of Retainer onto Accelerator Cable and the proper attention must be made to press the Retainer into hole on Rod to assure the Cable is not "KINKED"...
Page 458 6 M - 3 4 ENGINE FUEL AIR CLEANER B O TTO M ARRESTOR ASSEMBLY ■ ■ - r f W lE W A Fig. 2A -Engine Ventilation, (L-6) ELEMENT C O VE R Fig. 1A -Paper Element Air Cleaner M AINTENA N CE A N D SERVICE CARBURETOR AIR CLEANER ELEMENT-Under enrichment of carburetor mixture.
Page 459 W IN G NUT T O R Q U E AT 2 0 IN. LBS. AIR C LEA N ER G A S K E T IN O TEI Colored adhesive surface to carburetor STUD TO R Q U E AT 2 0 IN. LBS. TO RQ U E AT 75 IN.
Page 460 6 M - 3 6 ENGINE FUEL 17 IN. LBS. TORQUE a i r u A.W3SjV STUD (17 IN. LBS.) y« CARBURETOR EXTENSION VIEW B SUPPORT STUD 10-15__________> GASKET OIL LEVEL AIR CLEANER GAGE TUBE COIL EXTENSION STUD VIEW A GASKET I NOTE I Position red TUBE...
Page 461 E N G IN E FUEL 6 M - 3 7 AIR CLEANER STUD OIL GAGE TUBE SUPPORT — OIL GAGE PS100-150(35) TUBE ASM PS200-250 NOTE Stud must be installed with EXTENSION chamber end up. UPC 6Y VIEW A NOTE Position red adhesive surface down when installing gaskets.
Page 462 6 M - 3 8 ENGINE FUEL position through snorkel opening. Snorkel passage should be open. Fig. 11 A, View A. If not, check for W IN G J s lU T binds in linkage. T O R Q U E A T 2 0 LBS. IN 3.
Page 463 E N G IN E FUEL 6 M - 3 9 Fig. lOA-Thermostatically Controlled Air Cleaner AIR BLEED VALVE VIEW B -U N D E R H O O D TEMPERATURE CLOSED VIEW A —ENGINE OFF BELOW 85°F DIAPHRAGM SPRING TEMP.
Page 464 6 M - 4 0 ENGINE FUEL 3. Remove clip and sensor from air cleaner. 2. Press retaining clip on sensor. Support the sensor on its side to prevent damage to the control mechanism in the center. Replacement 1. Install sensor and gasket assembly in air cleaner in 3.
Page 465 E N G IN E FUEL 6 M -41 Fig. 2P--Fuel Pump and Pipe, V-8 a. Attach a fuel pump pressure test gauge to disconnect end of pipe. b. Run engine at approximately 450-1,000 rpm .(on gasoline in carburetor bowl) and note reading on pressure gauge.
Page 466 6 M - 4 2 ENGINE FUEL Fig. 4P--lnstalling V-8 Engine Fuel Pump CARBURETOR DIAGNOSIS MODELS M , M V -2 G , 2 G V -4 M , 4M V . INDEX Rochester Monojet (1 bbl.) C arburetor....6M-43 Rochester 4MV (4 bbl.) Carburetor......
Page 467 E N G IN E FUEL 6 M - 4 3 ROCHESTER CARBURETOR DIAGNOSIS MODELS M , M V - 2 G , 2 G V - 4 M , 4 M V . NOTE: These problems can be caused by many things other than carburetor. Check the following engine tune-up items before proceeding w ith carburetor items.
Page 468 6 M - 4 4 ENGINE FUEL ROCHESTER CARBURETOR DIAGNOSIS MODELS M, MV POSSIBLE CAUSE CORRECTIVE ACTION Carburetor flooding (continued) 3. Check float needle and seat for proper seal. If a needle and seat tester is not available, apply mouth suction to the needle seat w ith needle installed.
Page 469 E N G IN E FUEL 6 M - 4 5 ROCHESTER CARBURETOR DIAGNOSIS MODELS M, MV CORRECTIVE ACTION POSSIBLE CAUSE Carburetor flooding (continued) NOTE: A solid float can be checked fo r fuel absorption by lightly squeezing between fingers. If wetness appears on surface or float feels heavy (check w ith known good float, replace the float assembly.
Page 470 6 M - 4 6 ENGINE FUEL MODELS M, MV ROCHESTER CARBURETOR DIAGNOSIS PO SSIBLE CAUSE C O R R E C T IV E ACTION D irt in pump passages or pump jet. Clean and Blow out with compressed air. Fuel level.

Chevrolet Light Duty Truck 1973 Service Manual

Quick Links

Chapters

Related Manuals for Chevrolet Light Duty Truck 1973

Summary of Contents for Chevrolet Light Duty Truck 1973

Table of Contents