GMC 1982 Light Duty Truck Service Manual page 19

OB-10 MAINTENANCE AND LUBRICATION
abnormal tire wear, adverse vehicle handling, and reduced
fuel mileage. Too high an air pressure can result in
abnormal wear, harsh ride, and also increase the chance of
damage from road hazards. See Fig. OB-10.
See your O w n er's M a n u a l for additional detailed
information on proper tire care.
A -8 Brakes
Disc Brakes - Inspect disc brake pads for wear, and
rotors for surface condition when wheels are removed for
rotation.
Brake Lines - Inspect brake lines and hoses for proper
hook-up, binding, leaks, cracks, chafing, etc. When rubbing
or wear is noted on lines or hoses, the cause must be
corrected at once.
D rum and Parking Brakes — Inspect dru m brake
linings for wear and cracks. Inspect other brake parts
including drums, wheel cylinders, etc., at the same time.
Check parking brake adjustment.
I N S P E C T B R A K E S M O R E O F T E N IF H A BITS
O R C O N D I T I O N S R E S U L T
B R A K IN G .
A -9 Engine Drive Belts
Inspect belts driving the fan. A IR pump, generator,
power steering pump, and the air conditioning compressor.
Look for cracks, fraying, wear, and proper tension. Adjust
or replace as needed.
A -1 0 Fuel, Tank, C ap and Lines
Inspect the fuel tank, cap and lines for damage or leaks.
Remove fuel cap, inspect gasket for an even filler neck
imprint, and any damage. Replace parts as needed.
A - l 1 Throttle Linkage
Inspect for damaged or missing parts, interference or
binding. Fix any problems at once.
A - l 2 Cooling System
The coolant recovery system is standard. The coolant in
the radiator expands with heat, and the overflow is collected
in the recovery tank. W hen the system cools down, the
coolant is drawn back into the radiator.
The cooling system has been filled at the factory with a
quality coolant. The coolant is a 50/50 mixture of water and
ethylene glycol antifreeze.
Service
• Maintain cooling system freeze protection at -34°F
(-37°C) to ensure protection against corrosion and loss
of coolant from boiling. This should be done even if
freezing temperatures are not expected.
• Add ethylene glycol base coolant when coolant has to
be added because of coolant loss or to provide added
protection against freezing at temperatures lower than
-34°F(-37°C).
• Alcohol or methanol base coolants or plain water alone
follows:
1. Wash radiator cap and filler neck with clean water.
2. Check coolant level and test for freeze protection.
3. Test system and ra d ia to r cap for proper pressure
4. Tighten hose clamps and inspect all hoses. Replace
5. Clean frontal area of radiator core and air conditioning
R adiator Pressure C ap
must be installed tightly, otherwise coolant may be lost and
dam age to engine may result from overheating. Radiator
pressure cap should be checked periodically for proper
operation.
IN F R E Q U E N T
Therm ostat
thermostat. It stops coolant flow through the radiator until a
pre-set temperature is reached. This thermostat is installed
on the engine block. The same thermostat is used in both
winter and summer. Refer to Section 6B-Engine Cooling for
additional information.
A - 13 M a n u a l Steering G e a r
lubricant. Seasonal change of this lubricant should not be
performed and the housing should not be drained-no
lubrication is required for the life of the steering gear.
oily film). If a seal is replaced or the gear is overhauled, the
gear housing should be refilled only with the proper Steering
Gear Lubricant as noted in Fig. 0 B - 12.
A - 14 Final Drive
Trucks W ith Four W heel Drive
four wheel drive-equipped vehicles are the same for
corresponding components of conventional drive vehicles.
each 4 months or 6,000 miles (9 600 km).
Transfer Case
necessary, add Dexron ® 11.
Front Axle
refilled with S A E 80W -90 GL-5 gear lubricant when
necessary. With the differential at operating temperature
fill to the level of filler plug hole. If differential is cold, fill to
level of 1/2 inch below the filler plug hole.
should not be used in a vehicle at any time.
The cooling system should be serviced each year as
holding capacity, 15 psi (105 kPa). If replacement cap
is needed, use a cap designed for coolant recovery
systems and specified model.
hoses if swollen, "checked", or otherwise deteriorated.
condenser.
The radiator cap, a 15 psi (105 kPa) pressure type,
The engine coolant te m p e ra tu re is controlled by a
The steering gear is factory-filled with steering gear
Inspect for seal leakage (actual solid grease-not just
NOTICE: Do not use EP chassis lube, meeting GM
Specification 6 0 3 1M, to lubricate the gear. DO N O T
O V E R -F IL L the gear housing.
Most lubrication recommendations and procedures for
In addition, the following items require lubrication
Check the transfer case level at the interval and if
The front axle should be checked at the interval and