Page 2 FOREWORD This manual, which is written for engineers who service the machine, describes procedures for disassembly and assembly, inspection and maintenance, and troubleshooting, as well as maintenance reference values and an outline of the speciﬁca- tions. Refer to this manual during daily work to improve your services. Note that the information is subject to change without notice due to design modiﬁcations made to the machine from time to time by the manufacturer.
Page 3 SAFETY Safety alert symbol ............1-2 Safety precautions ............1-3 Cautions when working ..........1-9...
Page 4: Safety Alert Symbol
SAFETY SAFETY ALERT SYMBOL SAFETY ALERT SYMBOL This symbol represents the safety alert. The message that follows the symbol contains important information regard- ing human safety. Read and understand the message to avoid personal injury or death. Safety label Safety labels are used to alert operators or other people exposed to the risks of injury or damage.
Page 5: Safety Precautions
SAFETY SAFETY PRECAUTIONS Install an extinguisher and a ﬁrst aid kit SAFETY PRECAUTIONS Observe all safety rules • Operation, inspection and maintenance of this machine must be performed only by a trained and qualiﬁed per- son. • All rules, regulations, precautions and safety procedures must be understood and followed when performing op- eration, inspection and maintenance of this machine.
Page 6 SAFETY SAFETY PRECAUTIONS Regularly replace the safety-critical parts When the canopy is tilted up • Regularly replace fuel hoses to prevent a ﬁre hazard. • If the canopy is raised or lowered while the engine is Hoses wear out over time, even if they do not show any moving, the machine may accidentally start moving, re- symptom of wear.
Page 7 SAFETY SAFETY PRECAUTIONS Keep clear of the moving fan and belt When working on the machine 1BAA09Z 1BAA07Z • Any object that can be easily caught in moving parts • To prevent slipping/falling from machine, clear the foot- must be kept away. ing and observe the following: •...
Page 8 SAFETY SAFETY PRECAUTIONS Caution when ﬁlling with fuel or oil Be careful with hot and pressurized components 1BAA12Z 1BAA11Z • Keep away from heat, sparks and ﬂame while ﬁlling with Before performing inspection and maintenance, stop the fuel or oil. engine and allow the machine to cool down.
Page 9 SAFETY SAFETY PRECAUTIONS Be careful with oils under pressure Be careful with grease under pressure 1BAA14Z 1BAA15Z Pressure is maintained in the hydraulic circuit long after the In the track adjuster, the grease has been injected under engine has been shut down. high pressure.
Page 10: Checks After Maintenance
SAFETY SAFETY PRECAUTIONS Use caution when handling batteries Have a service agent repair welding cracks or other damage Ask a service agent to make any repairs that require weld- ing. If the agent is unavailable, make sure the welding is done by a qualiﬁed person in a properly equipped work- place.
Page 11: Cautions When Working
SAFETY CAUTIONS WHEN WORKING When removing/installing the hydraulic unit CAUTIONS WHEN WORKING • Make sure that the temperature of the hydraulic oil has When disassembling or assembling dropped and is cool enough to work with. • Clean the machine before disassembly. •...
Page 12 SAFETY CAUTIONS WHEN WORKING When connecting/disconnecting the hoses or Handling of seals pipes • Clean the grooves for O-rings and remove any burrs. • When hydraulic hoses or pipes are connected, tighten them once to the prescribed torque, then loosen them slightly and retighten them to the prescribed torque.
Page 13: Table Of Contents
SERVICE DATA Dimensional drawing ........... 2-2 Speciﬁcations tables ............ 2-4 Lubricant and Fuel chart ..........2-9 Performance criteria ..........2-11 Tightening torque ............2-21 Hydraulic circuit diagram ........... 2-25 Electric circuit diagram ..........2-33 Wire harness wiring diagram ........2-37...
Page 14: Table Of Contents
SERVICE DATA DIMENSIONAL DRAWING DIMENSIONAL DRAWING Machine dimensions Unit: mm Standard arm Middle arm Long arm Rubber crawlers Steel crawlers Rubber crawlers Rubber crawlers 5470 5470 5510 5550 1690 1690 1690 1690 2515 2520 2515 2515 1435 1435 1435 1435 1985 1920 1985...
Page 15: Table Of Contents
SERVICE DATA DIMENSIONAL DRAWING Operating range Unit: mm Standard arm Middle arm Long arm Rubber crawlers Rubber crawlers Rubber crawlers 5850 5990 6135 5705 5850 5995 3475 3625 3785 2725 2860 2990 3935 3985 4055 5625 5715 5800 3990 4085 4175 1595 1450...
Page 16: Service Data
SERVICE DATA SPECIFICATIONS TABLES SPECIFICATIONS TABLES 4965 Operating mass Canopy 4825 29.5/2400 Net (ISO 14396) kW/min Rated output Net (ISO 9249/SAEJ1349) kW/min 28.4/2400 Heaped capacity 0.141 Bucket capacity Struck capacity 0.102 Performance Standard loading mass Slew speed km/h Travel speed km/h Maximum tractive force 56.1...
Page 17 SERVICE DATA SPECIFICATIONS TABLES Engine Model YANMAR 4TNV88 Type 4-cycle, vertical, water-cooled, in-line, 4-cylinder diesel engine Number of cylinders -bore×stroke 4−88×90 Total displacement 2185 N·m 131.8 to 143.4 Maximum torque min-1 1440 Speciﬁc fuel consumption (at rated output) g/kW·h Fuel/air washer Centrifugal, ﬁlter paper Suction type Cooling system type...
Page 18 SERVICE DATA SPECIFICATIONS TABLES Slew equipment Slew bearing Type Ball bearing Type Variable displacement piston motor Slew motor Qty. Reduction gears Type Epicycle reduction gear Type Brake valve with a shockless relief Slew brake Qty. Slew parking brake parking Type Wet friction plate type ––...
Page 19 SERVICE DATA SPECIFICATIONS TABLES Working dimensions Maximum reach 5850 Maximum reach at ground reference plane 5710 Minimum level ﬂoor radius 1835 Maximum digging depth 3475 Reach at maximum digging depth 2400 Maximum vertical digging depth 2725 Maximum height of cutting edge 5625 Reach at maximum height 3095...
Page 20 SERVICE DATA SPECIFICATIONS TABLES Dozer blade Type Straight type Operation type Hydraulic lifting type Number of cylinders Qty. Dozer blade cylinder Bore Stroke Dimensions Width 1840 Dozer blade dimensions Height Cutting angle degree Distance between the front end of dozer blade and 1720 the axis of rotation Dozer blade maximum lifting...
Page 21 *** The replacement interval for hydraulic oil depends on the oil type being used. New machines are shipped from the fac- tory with the Takeuchi genuine hydraulic oil 46. This manual describes when to replace the hydraulic oil assuming that...
Page 22 SERVICE DATA LUBRICANT FUEL AND CHART Diesel fuel standards Use the diesel fuel that is compliant with any of the stan- dards below. The table below shows the standards from the various countries. Diesel fuel standards Region No. 2-D, No. 1-D, ASTM D975-94 EN590:96 ISO 8217 DMX International standard...
Page 23: Performance Criteria
SERVICE DATA PERFORMANCE CRITERIA PERFORMANCE CRITERIA Standard values table Item Standard values Allowable value Idling 1150 ±100 –– Engine speed Maximum R. P. M 2565 ±80 –– Boom 21.0 –– +1.3 -0.4 21.0 –– +1.3 -0.4 Hydraulic oil pressure Dozer blade 19.6 ––...
Page 24 SERVICE DATA PERFORMANCE CRITERIA Item Standard values Allowable value Boom Arm (With emergency shut-off valve) Natural cylinder drop Bucket Dozer blade Bucket tip -110 Bucket tip (With emergency shut-off valve) Backlash 17 ±10 Right operating lever –– Left operating lever ––...
Page 25 SERVICE DATA PERFORMANCE CRITERIA Hydraulic pump assignment table 2DAA01Z Right travel, Boom, Bucket 58.3 L/min Left travel, Arm, Swing, Auxiliary line 58.3 L/min Slew, Dozer blade, Second auxiliary line 38.9 L/min Pilot pressure 10.8 L/min Pump P1 Right travel Pressure: 21.0 MPa Test port P2 Boom Pressure: 21.0 MPa...
Page 26 SERVICE DATA PERFORMANCE CRITERIA Methods for inspecting performance �� Hydraulic oil pressure (Main relief valve set pres- �� sure) Boom, Arm, Dozer Blade Measuring Method • Engine: Maximum R. P. M. • Hydraulic oil temp.: 50~60°C • Mount the pressure gauge on the pressure detection port, operate the desired hydraulic circuit and measure the relief pressure.
Page 27 SERVICE DATA PERFORMANCE CRITERIA Hydraulic oil pressure (Slewing relief valve set pressure) �� Measuring method �� • Engine: Maximum R. P. M. • Hydraulic oil temp.: 50~60°C • Mount the pressure gauge on the pressure detection port and set a solid obstacle so that the upperstructure cannot slew in the direction to be measured.
Page 28 SERVICE DATA PERFORMANCE CRITERIA Travel speed (5 revolutions) • Engine: Maximum R. P. M. • Hydraulic oil temp.: 50~60°C • Measurement posture: Excavator body raised using both hoe attachment and dozer blade. • Set crawler belts in motion. Starting after one full revo- lution, measure the time required for 5 revolutions.
Page 29 SERVICE DATA PERFORMANCE CRITERIA Natural travel drop • Engine: Stopped • Hydraulic oil temp.: 50~60°C • Gradient: 15° • Measurement posture: Fully extend the boom, arm and bucket cylinders and completely retract the dozer blade cylinder. • With the excavator parked at angle for 5 minutes, mea- sure the extent of natural drop.
Page 30 SERVICE DATA PERFORMANCE CRITERIA Boom cylinder speed • Engine: Maximum R. P. M. • Hydraulic oil temp.: 50~60°C • Measurement posture: Completely retract the arm cyl- inder, fully extend the bucket cylinder and rest the dozer blade on the ground. •...
Page 31 SERVICE DATA PERFORMANCE CRITERIA Swing cylinder speed • Engine: Maximum R. P. M. • Hydraulic oil temp.: 50~60°C • Measurement posture: Same as that for measuring slew time. • While swinging the boom left (right) to right (left), mea- sure the time required for a full stroke each way. (Do not include the cushioning time.) Natural cylinder drop Boom, arm, bucket, dozer blade, bucket tip...
Page 32 SERVICE DATA PERFORMANCE CRITERIA Lever Play • Measure any discernible play at the tip of the lever (ped- al). Backlash • Measurement Posture : Completely retract the arm cyl- inder and fully extend the bucket cylinder. • Move the tips of the bucket teeth from side to side (left and right) and measure the play.
Page 33: Tightening Torque
SERVICE DATA TIGHTENING TORQUE TIGHTENING TORQUE Hydraulic hose Tightening torque �� Hose ﬁtting size Union nut (G) Taper thread (R) �� N·m N·m 11.8 ±1.2 +4.9 �� 24.5 29.4 ±2.9 +4.9 �� 49.0 53.9 ±5.4 +4.9 58.8 88.3 ±8.8 +4.9 117.7 147.1 ±14.7...
Page 34 SERVICE DATA TIGHTENING TORQUE Joint for piping Tightening torque Nominal thread Steel Cast steel diameter N·m N·m 11.8 ±1.2 10.8 ±1.1 29.4 ±2.9 24.5 ±2.5 53.9 ±5.4 49.0 ±4.9 88.3 ±8.8 73.5 ±7.4 147.1 ±14.7 127.5 ±12.7 196.1 ±19.2 171.6 ±17.2 2EAA03Z Joint for piping (O-ring seal type) Tightening torque...
Page 35 SERVICE DATA TIGHTENING TORQUE Bolts and nuts (JIS strength category 10.9) Tightening torque Thread Size × pitch General tightening points Special tightening points N·m N·m M6 × 1.0 9.8 ±0.5 11.8 ±1.1 M8 × 1.25 22.6 ±1.1 26.5 ±2.5 M10 × 1.5 47.1 ±2.4 54.9 ±4.9 Coarse...
Page 36 SERVICE DATA TIGHTENING TORQUE 2-24...
Page 37: Hydraulic Circuit Diagram
SERVICE DATA HYDRAULIC CIRCUIT DIAGRAM HYDRAULIC CIRCUIT DIAGRAM Equipped with options 1/2 2-25...
Page 38 SERVICE DATA HYDRAULIC CIRCUIT DIAGRAM Equipped with options 2/2 2-26...
Page 39 SERVICE DATA HYDRAULIC CIRCUIT DIAGRAM Equipped with angle blade and blade ﬂoat 1/2 2-27...
Page 40 SERVICE DATA HYDRAULIC CIRCUIT DIAGRAM Equipped with angle blade and blade ﬂoat 2/2 2-28...
Page 41 SERVICE DATA HYDRAULIC CIRCUIT DIAGRAM Equipped with high-ﬂow (option) 1/2 2-29...
Page 42 SERVICE DATA HYDRAULIC CIRCUIT DIAGRAM Equipped with high-ﬂow (option) 2/2 2-30...
Page 43 SERVICE DATA HYDRAULIC CIRCUIT DIAGRAM Equipped with high-ﬂow, angle blade, blade ﬂoat (option) 1/2 2-31...
Page 44 SERVICE DATA HYDRAULIC CIRCUIT DIAGRAM Equipped with high-ﬂow, angle blade, blade ﬂoat (option) 2/2 2-32...
Page 45: Electric Circuit Diagram
SERVICE DATA ELECTRIC CIRCUIT DIAGRAM ELECTRIC CIRCUIT DIAGRAM First auxiliary hydraulic piping with on/off switch 2-33...
Page 46 SERVICE DATA ELECTRIC CIRCUIT DIAGRAM First auxiliary hydraulic piping with proportional control 2-34...
Page 47 SERVICE DATA ELECTRIC CIRCUIT DIAGRAM First auxiliary hydraulic piping with on/off switch, second auxiliary hydraulic piping with bucket select switch 2-35...
Page 48 SERVICE DATA ELECTRIC CIRCUIT DIAGRAM First auxiliary hydraulic piping with proportional control, second auxiliary hydraulic piping with bucket select switch 2-36...
Page 50: Wire Harness Wiring Diagram
SERVICE DATA WIRE HARNESS WIRING DIAGRAM WIRE HARNESS WIRING DIAGRAM Upper frame wiring 1/2 Upper frame wiring 2/2 Serial No. 125000001 to 125000849 1. Control unit 1. Plate 2. Wire harness (03942-26630) 2. Flip ﬂop unit 3. Fusible link 3. Relay 4.
Page 51 SERVICE DATA WIRE HARNESS WIRING DIAGRAM Upper frame wiring 2/2 Serial No. 125000850 or later 1. Plate 2. Flip ﬂop unit 3. Relay 4. Relay 5. Resistance 6. Relay 7. Controller 8. Buzzer 9. Timer 10. Safety relay 11. Diode unit 2-38...
Page 52 SERVICE DATA WIRE HARNESS WIRING DIAGRAM Upper frame wiring (ﬁrst auxiliary hydraulic piping with proportional control) Upper frame wiring (ﬁrst auxiliary hydraulic piping with proportional control and foot switch) 1. Wire harness (03942-26910) 1. Wire harness (03742-19410) 2. Wire harness (03742-17510) 2.
Page 53 SERVICE DATA WIRE HARNESS WIRING DIAGRAM Upper frame wiring (ﬁrst auxiliary hydraulic piping with on/off switch and foot switch) Upper frame wiring (equipped with angle blade) 1. Wire harness (03742-19310) 1. Wire harness (03742-23010) 2. Diode 3. Flip ﬂop unit 4.
Page 54 SERVICE DATA WIRE HARNESS WIRING DIAGRAM Control unit (second auxiliary hydraulic piping with bucket select switch) Control unit (ﬁrst auxiliary hydraulic piping with on/off switch) 1. Wire harness (03570-15570) 1. Resistance 2. Diode 2. Relay 3. Relay 3. Wire harness (03942-26810) 4.
Page 55 SERVICE DATA WIRE HARNESS WIRING DIAGRAM Control unit (Air conditioner) Control unit (travel alarm) 1. Relay 2. Wire harness (03942-27110) 3. Diode 4. Buzzer 1. Control ampliﬁer 2. Relay (Air conditioner) 3. Relay (Compressor) 4. Wire harness (03946-21310) (Serial No. 125000001 to 125000939) Wire harness (03946-21320) (Serial No.
Page 56 SERVICE DATA WIRE HARNESS WIRING DIAGRAM Control unit (arm holding limit) Control unit (automatic deceleration) 1. Relay 1. Wire harness (03742-17710) 2. Wire harness (03760-15590) 2. Diode 3. Diode 3. Relay 4. Timer unit 5. Flip ﬂop unit 6. Relay 2-43...
Page 57 SERVICE DATA WIRE HARNESS WIRING DIAGRAM Control unit (heater for cold climate) 1. Control ampliﬁer 2. Relay 3. Wire harness (03745-08250) (Serial No. 125000001 to 125000939) Wire harness (03745-08260) (Serial No. 125000940 or later) 4. Short connector 5. Control unit 6.
Page 58 SERVICE DATA WIRE HARNESS WIRING DIAGRAM Auxiliary piping detent (ﬁrst auxiliary hydraulic piping with on/off switch) Auxiliary piping detent (ﬁrst auxiliary hydraulic piping with proportional control) 1. Wire harness (03742-19450) 1. Wire harness (03742-19440) 2. Relay 2. Relay 3. Flip ﬂop unit 3.
Page 59 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-46...
Page 60 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-47...
Page 61 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-48...
Page 62 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-49...
Page 63 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-50...
Page 64 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-51...
Page 65 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-52...
Page 66 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-53...
Page 67 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-54...
Page 68 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-55...
Page 69 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-56...
Page 70 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-57...
Page 71 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-58...
Page 72 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-59...
Page 73 SERVICE DATA WIRE HARNESS WIRING DIAGRAM STANDARD NAME 2-60...
Page 74 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-61...
Page 75 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-62...
Page 76 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-63...
Page 77 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-64...
Page 78 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-65...
Page 79 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-66...
Page 80 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-67...
Page 81 SERVICE DATA WIRE HARNESS WIRING DIAGRAM 2-68...
Page 82 FUNCTION Piston pump ..............3-2 Gear pump ..............3-5 Control valve ..............3-6 Pilot valve ..............3-12 Proportional control solenoid valve ......3-13 Emergency shut-off valve ........... 3-14 CylinderS ..............3-15 Travel motor .............. 3-16 Slew motor ..............3-20 Swivel joint ..............3-24...
Page 83 FUNCTION PISTON PUMP PISTON PUMP Operation This pump is a variable displacement piston pump with a single cylinder block, which discharges two equal volumes. Ten pistons (2) are installed in the cylinder block (1), and the end surface is in contact with the valve plate (3).
Page 84 FUNCTION PISTON PUMP When the discharge pressure exceeds the set value of the spring (7), the swash plate (4) is pushed by the pistons (9) and (10), the inclination decreases, and the swash plate is kept at an inclination where the discharge pressure and the spring force are bal- anced.
Page 85 FUNCTION PISTON PUMP Relief valve and solenoid valve � � �� If the oil pressure discharged from the pump P4 (2) be- comes higher than the set value, the relief valve (1) releases �� the oil into the tank circuit. In this way, the relief valve (1) keeps the pressure in the pilot circuit constant.This pilot �...
Page 86 FUNCTION GEAR PUMP GEAR PUMP The gear pump is composed of two mutually engaging gears (drive gear (1) and driven gear (2)) contained in a gear case. When the drive shaft (3) is rotated, the space be- tween the case and the gears is ﬁlled with oil that is ﬂowing from the inlet to the outlet.
Page 87 FUNCTION CONTROL VALVE CONTROL VALVE When the spools are in the neutral position: When the control valve spools are not moved, the oil ﬂows through the center bypass passage (1) and the tank pas- sage T to return to the tank, as shown by the arrow. 3JAA01Z When the spool is operated: When the spool is moved to the right:...
Page 88 FUNCTION CONTROL VALVE Main relief valve The main relief valve is mounted between the pump circuit and tank circuit of each inlet housing, and serves to main- tain the circuit pressure at the set value. The relief valve remains turned off: �...
Page 89 FUNCTION CONTROL VALVE If the pressure in the circuit becomes higher than the force of the spring (7), the needle valve (5) is pushed to the right by hydraulic pressure, connecting the high-pressure area with the tank passage T. The oil then ﬂows around the cir- cumference of the needle valve (5) and passes through the slits, ﬂowing into the tank passage T.
Page 90 FUNCTION CONTROL VALVE Anti-cavitation valve This valve is installed between the cylinder port and the tank passage. If the cylinder is operated at a speed too fast for the oil supply to keep up with, and thus the pressure of the cylinder port becomes negative, the oil from the tank is supplied to prevent cavitation.
Page 91 FUNCTION CONTROL VALVE When the Boom Lower operation is performed �� When the Boom Lower operation is performed, the pilot � pressure is led to the port P1 to push down the spool (3). This allows the oil in the spring chamber (5) to ﬂow through �...
Page 92 FUNCTION CONTROL VALVE 3-11...
Page 93 FUNCTION PILOT VALVE PILOT VALVE The pilot valve casing contains the vertical shaft holes that incorporate the reducing valves. When the lever is tilted, the push rod and spring seat are pushed down, changing the spring force of the secondary pressure. The casing contains the oil inlet port P (the primary pres- sure) and the tank port T.
Page 94 FUNCTION PROPORTIONAL CONTROL SOLENOID VALVE PROPORTIONAL CONTROL SOLENOID VALVE This valve controls the secondary pressure by using the built-in proportional pressure reducing valve. The secondary pressure generated corresponds to the S=A1-B1 changes in current, because the force used to generate the secondary pressure is applied to the solenoid according to B1 A1 the current passing through the coil.
Page 95 FUNCTION EMERGENCY SHUT-OFF VALVE EMERGENCY SHUT-OFF VALVE This valve prevents the boom or arm being raised from fall- ing. If the hydraulic hose breaks, the valve shuts off the oil ﬂow pushed back from the cylinder and prevent it from further ﬂowing.
Page 96 FUNCTION CYLINDERS CYLINDERS The pressure oil alternately ﬂowing into the piston through the outlet and inlet on both sides (head and rod sides) causes the piston to perform the reciprocating motion. For those cylinders with a cushion mechanism, the shock resulting from the piston colliding with the cover at the stroke end is dampened by the mechanism.
Page 97 FUNCTION TRAVEL MOTOR TRAVEL MOTOR Hydraulic motor The cylinder block (1) is constructed with the pistons (2), and its end surface comes in contact with the valve plate (3) containing two half-moon-shaped ports (B) and (C). The cylinder block (1) rotates freely and is connected to the shaft (4) via the splines.
Page 98 FUNCTION TRAVEL MOTOR When the high pressure oil directed to the port P1 is shut � � � off, the pressure in the port P1 becomes equal to that of the port P2 and the spool (8) returns to the neutral posi- tion.
Page 99 FUNCTION TRAVEL MOTOR Swash plate � The swash plate (5) has three planes of A, B and C, as � shown in the ﬁgure, and it is mounted to the ﬂange holder � (6) in such a way that its angle of inclination to the ﬂange holder (6) can be changed by means of the two steel balls �...
Page 100 FUNCTION TRAVEL MOTOR Parking brake The friction disc (2) and the disc (1) are connected through the spline. The friction disc (2) and the disc (1) are pressed against the ﬂange holder (6) by the springs (4) via the brake piston (5).
Page 101 FUNCTION SLEW MOTOR SLEW MOTOR Hydraulic motor The cylinder block (1) is constructed with the pistons (2), and its end surface comes in contact with the valve plate (3) containing two half-moon-shaped ports B and C. The cylinder block (1) rotates freely and is connected to the drive shaft (4) via the spline.
Page 102 FUNCTION SLEW MOTOR Make-up valve The makeup valve has two functions: One function is to prevent the slewing structure from run- ning away by preventing the cavitation caused by overrun of the piston motor. The inertia of the slewing mechanism rotates the motor, pumping up the oil.
Page 103 FUNCTION SLEW MOTOR The rebound pressure also pushes the check valve (1) to � � the left, which is the opposite direction when braking. The ﬂow control valve built in the check valve (2) (that is now on the lower pressure side) releases the oil in the damper chamber (4) at a constant ﬂow rate.
Page 104 FUNCTION SLEW MOTOR Timer valve � � This valve is used to prevent sudden operation of the park- �� ing brake when the motor is stopped. �� When the parking brake is activated, the pressure oil from the port P4 is supplied at all times to the port PG, the spool (1) is pushed to the right by the spring (2) force, and the port PG is closed When the slew pilot pressure or arm pilot pressure is di-...
Page 105 FUNCTION SWIVEL JOINT SWIVEL JOINT � � The swivel joint is mounted in the center of the machine’s � slew axis. It serves the role of maintaining continuous con- nections in the hydraulic circuit, regardless of the upper � frame slew angle. The ports (3) are ﬁtted on the hub (1) and the shaft (2).
Page 106 DISASSEMBLY AND ASSEMBLY Service standards ............4-2 Drive system ..............4-5 Travel system ............. 4-14 Slew system .............. 4-19 Upper frame .............. 4-22 Control system ............4-28 Attachments .............. 4-39 Hydraulic tank ............4-45 Hydraulic pump ............4-50 Control valve .............. 4-74 Pilot valve ..............
Page 107 DISASSEMBLY AND ASSEMBLY SERVICE STANDARDS SERVICE STANDARDS Carrier roller Criteria (mm) Code Standard dimension Allowable value � � –– �� Track roller Criteria (mm) Code Standard dimension Allowable value –– � � �� Drive sproket � Criteria (mm) Code Standard dimension Allowable value 380.4 �...
Page 108 DISASSEMBLY AND ASSEMBLY SERVICE STANDARDS Clearance for pin and bushing...
Page 109 DISASSEMBLY AND ASSEMBLY SERVICE STANDARDS Unit: mm Code Item Criteria Action Tolerance Standard Standard Allowable dimension clearance clearance Axis Hole Bucket and arm -0.02 +0.025 0.045 to 0.170 -0.05 +0.120 -0.02 +0.025 Bucket and link 0.045 to 0.170 -0.05 +0.120 -0.02 +0.025 Arm and link...
Page 110 DISASSEMBLY AND ASSEMBLY DRIVE SYSTEM DRIVE SYSTEM Removing the engine � � �� B: With the marker “B” C: With the marker “C”...
Page 111 DISASSEMBLY AND ASSEMBLY DRIVE SYSTEM 1. Disconnect the battery ground cable from the battery terminal. 2. Remove the canopy. “Removing the canopy” 3. Remove the ﬂoor frame. “Removing the ﬂoor frame” 4. Disconnect the electrical wiring to the air cleaner (14). 5.
Page 112 DISASSEMBLY AND ASSEMBLY DRIVE SYSTEM Removing the radiator and oil cooler � �� 1.
Page 113 DISASSEMBLY AND ASSEMBLY DRIVE SYSTEM 1. Loosen the radiator cap to let engine coolant drain from the drain valve (11). • Engine coolant volume: 12.4 L 2. Disconnect the drain hoses (12) and (13). 3. Disconnect the radiator hoses (8) and (9) and the hose.
Page 114 DISASSEMBLY AND ASSEMBLY DRIVE SYSTEM Removing the hydraulic pump � � � � � �� Apply molybdenum disulﬁde grease to the spline 1. Engine housing 2. Hydraulic pump 3. Coupling 4. Air-bleeding plug 5. Solenoid valve...
Page 115 DISASSEMBLY AND ASSEMBLY DRIVE SYSTEM 1. Remove the canopy or the cab. “Removing the cab” 2. Remove the engine hood and the engine cover. “Removing the covers” 3. Drain the oil from the hydraulic oil tank. “Removing the hydraulic tank” 4.
Page 116 DISASSEMBLY AND ASSEMBLY DRIVE SYSTEM Removing the fuel tank � �� 1. Fuel tank 8. Fuel hose 2. Flange 9. Fuel hose 3. Fuel sender 10.
Page 117 DISASSEMBLY AND ASSEMBLY DRIVE SYSTEM 1. Remove the canopy or the cab. “Removing the cab” 2. Remove the covers around the tank. “Removing the covers” 3. Loosen the drain valve (5) to drain the fuel. • Fuel tank capacity: 73 L 4.
Page 118 DISASSEMBLY AND ASSEMBLY DRIVE SYSTEM Adjusting the throttle lever Engine revolution � 1. Fasten the wire (2) to the throttle lever (1) with the wire � lock pin (3). 2. Move the throttle lever (1) to the “A” (low idle) position and the governor (4) to the “C”...
Page 119 DISASSEMBLY AND ASSEMBLY TRAVEL SYSTEM TRAVEL SYSTEM � Removing the crawler belt � 1. Loosen the tension of the crawler (1). • When loosening the check valve (2), do it slowly. When grease comes out, stop loosening it. If no grease comes out, slightly move the machine for- �...
Page 120 DISASSEMBLY AND ASSEMBLY TRAVEL SYSTEM Removing the steel crawler 1. Stop the machine so that the master pin comes to the front of the idler. 2. Relax the tension of the crawler (1). When loosening the check valve (2), do it slowly and stop as soon as grease start coming out.
Page 121 DISASSEMBLY AND ASSEMBLY TRAVEL SYSTEM Removing the Carrier Roller 1. Relax the crawler belt tension. 2. Using a hydraulic jack, push up the crawler belt. 3. Loosen the ﬁxing nut (3) to remove the bolt, and then remove the roller (4). �...
Page 122 DISASSEMBLY AND ASSEMBLY TRAVEL SYSTEM Exchanging between rubber crawlers and steel crawlers Required parts Item Part No. Name Quantity 03913-00400 Spacer 11010-51255 Bolt 04610-00700 Guide 11010-41230 Bolt 11400-20012 Washer WARNING If you must work beneath the raised machine or equip- ment, always use wood blocks, jack stands or other rigid and stable supports.
Page 123 DISASSEMBLY AND ASSEMBLY TRAVEL SYSTEM Removing the idler and the track adjuster 1. Remove the crawler. “Removing the crawler belt” 2. Pull out the idler and the track adjuster. Idler + track adjuster: 67 kg �� Installing the idler and the track adjuster For installation of the idler and the track adjuster, follow the same procedure as for removal in the reverse order.
Page 124 DISASSEMBLY AND ASSEMBLY SLEW SYSTEM SLEW SYSTEM Removing the slew motor � 1. Slew motor �� 1. Tilt up the ﬂoor frame. 2. Disconnect the hydraulic hoses from the slew motor (1). 3. Remove the bolts ﬁxing the slew motor. Bolt: ThreeBond #1324 Bolt: 256 N·m 4.
Page 125 DISASSEMBLY AND ASSEMBLY SLEW SYSTEM Removing the slew bearing � 1. Slew bearing �� 1. Remove the hoe attachment. “Removing the hoe attachment” 2. Remove the upper frame. 3. Remove the inner race ﬁxing bolts. Bolt: ThreeBond #1324 Bolt: 256 N·m 4.
Page 126 DISASSEMBLY AND ASSEMBLY SLEW SYSTEM Removing the swivel joint � � 1. Swivel joint 2. Stopper �� 1. Remove the upper frame. “Removing the upper frame” 2. Disconnect the hydraulic hoses from the hub side of the swivel joint (1). 3.
Page 127 DISASSEMBLY AND ASSEMBLY UPPER FRAME UPPER FRAME Removing the upper frame � 1. Upper frame � 2. Counterweight �� 3. Grease pipe �� 4-22...
Page 128 DISASSEMBLY AND ASSEMBLY UPPER FRAME 1. Remove the hoe attachment. “Removing the hoe attachment” 2. Remove the canopy or the cab. 3. Remove the covers. “Removing the covers” 4. Disconnect the hydraulic hoses from the swivel joint. 5. Remove the ﬁxing bolts and then the stopper. “Removing the swivel joint”...
Page 129 DISASSEMBLY AND ASSEMBLY UPPER FRAME Removing the covers � � � �� 1. Engine hood 8. Hinge 2. Front cover 9. Plate 3. Side cover R 10. Cover 4.
Page 130 DISASSEMBLY AND ASSEMBLY UPPER FRAME �� 15. Side frame R 16. Side frame L 17. Tool box 18. Cover 19. Bracket 20. Cover 4-25...
Page 131 DISASSEMBLY AND ASSEMBLY UPPER FRAME 1. Disconnect the battery ground cable from the battery terminal. 2. Remove the engine hood (1). a. Open the engine hood and suspend it temporarily. b. Disconnect the electric wiring of the taillight. c. Remove the stay damper (13). 3.
Page 132 DISASSEMBLY AND ASSEMBLY UPPER FRAME Removing the cab � 1. Cab assembly �� 1. Disconnect the battery ground cable from the battery terminal. 2. Disconnect the electric wiring from the cab. 3. Remove the ﬁxing bolts. 4. Suspend the cab and remove it. Cab: 240 kg Installing the cab For installation of the cab, follow the same procedure as for...
Page 133 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM CONTROL SYSTEM Removing the lever stand Control lever � � � � � � � � � � � � �� 1. Pedal assembly L 2. Pedal assembly R 3. Lever L 4. Lever R 5.
Page 134 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM Control lever pedal (Aux. 1 proportional control) � � � � � � � � � � � � �� 1. Pedal assembly L 2. Pedal assembly R 3. Lever L 4. Lever R 5. Proportional control valve 6.
Page 135 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM Control lever pedal (1st auxiliary ON/OFF) � � � � � � � � � � � � � �� 1. Pedal assembly L 2.
Page 136 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM Hydraulic pilot unit A type (ISO) �� ...
Page 137 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM A type(ISO) ↔G type(JCB) �� ...
Page 138 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM Blade lever � � � � � �� When assembling, be sure to apply NEVER SEEZ (anti-seize and lubricating agent) to the inner surfaces of the DU bush. 1. Base plate 2. Lever 3. Control cable 4.
Page 139 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM Lever stand � � � � � � �� 1. Bracket 2. Lever 3. Lever 4. Bracket 5. Control box 6. Plate 7. Pilot valve 8. Limit switch 9. Stay damper 10.
Page 140 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM Control box R (Cab) � � � �� 1. Cover R 2. Plate 3. Cover � 4. Starter switch � 5. Light switch 6. Cluster gauge �� 7. Valve � � 8.
Page 141 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM Control box L � � � � � � � � � � � 1. Cover L � 2. Cover L 3. Ornament 4. Ornament �� 5. Cover L A: Emergency shut-off valve B: Emergency shut-off valve, arm holding limit Control box L (with air conditioner and heater for cold climates) �...
Page 142 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM 1. Disconnect the battery ground cable from the battery terminal. 2. Remove the cab. “Removing the cab” 3. Remove the lever stand L. a. Remove the cover (upper) of control box L. b. Pull up the lock lever and lift up the lever stand. Then, pull out the pin and remove the lock lever.
Page 143 DISASSEMBLY AND ASSEMBLY CONTROL SYSTEM Adjusting the control cable Adjust the lever stroke length by using the setscrew so that it is long enough for the spool stroke on the control valve. 1. The control valve (1) spool should be in the neutral po- sition.
Page 144 DISASSEMBLY AND ASSEMBLY ATTACHMENTS ATTACHMENTS Removing the attachments �� 1. Bucket 8. Boom 2. Bucket link 9. Boom cylinder 3. Guide link R 10. Swing bracket 4. Guide link L 11.
Page 145 DISASSEMBLY AND ASSEMBLY ATTACHMENTS WARNING • Be sure to release the residual pressure from the hy- draulic hose before disconnecting it. • When adjusting the pin hole position, never put your ﬁnger into the hole. Important: • When tightening the lock bolt with a double nut, al- low a clearance of 0.5 to 1.0 mm between the nut and the lock collar.
Page 146 DISASSEMBLY AND ASSEMBLY ATTACHMENTS Removing the link � Fully retract the bucket cylinder and lower the front end of the arm to the ground. � 1. Pull out the cotter pin and remove the castle nut (1). 2. Suspend the bucket link (2) temporarily and remove the pin (3).
Page 147 DISASSEMBLY AND ASSEMBLY ATTACHMENTS Removing the boom � Lower the front end of the boom fully to the ground. 1. Disconnect the hydraulic hoses (1) from the arm cylin- der (2). 2. Suspend the arm cylinder (2) temporarily, pull out the pin (3) and then remove the arm cylinder.
Page 148 DISASSEMBLY AND ASSEMBLY ATTACHMENTS Removing the swing bracket 1. Suspend the boom cylinder (1) temporarily, pull out the � � � pin (2) and then remove the boom cylinder. Boom cylinder: 58 kg � � 2. Remove the blade (3) from the swing bracket (4). 3.
Page 149 DISASSEMBLY AND ASSEMBLY ATTACHMENTS Removing the dozer blade � Lower the dozer blade fully to the ground. � 1. Disconnect the hydraulic hoses (1) from the blade cyl- inder (2). 2. Suspend the blade cylinder (2) temporarily, pull out the �...
Page 150 DISASSEMBLY AND ASSEMBLY HYDRAULIC TANK HYDRAULIC TANK Removing the hydraulic tank �� ...
Page 151 DISASSEMBLY AND ASSEMBLY HYDRAULIC TANK 1. Remove the cab or the canopy. “Removing the cab” 2. Remove the covers around the tank. “Removing the covers” 3. Drain the hydraulic oil from the tank (1). a. Gradually loosen the ﬁller plug to release all internal pressure beforehand.
Page 152 DISASSEMBLY AND ASSEMBLY HYDRAULIC TANK Inspecting the hydraulic oil tank level and reﬁlling WARNING Oil may spurt out if caps or ﬁlters are removed or pipes are disconnected before releasing the pressure in the hydraulic system. • Slowly loosen the air-bleeding plug to relieve the in- ternal pressure of the hydraulic oil tank.
Page 153 DISASSEMBLY AND ASSEMBLY HYDRAULIC TANK Reﬁlling Important: Do not reﬁll to above the (H) mark. This can result in damage to the hydraulic circuit or cause oil to spurt out. If accidentally ﬁlled to above the (H) mark, stop the engine, and after allowing the hydraulic oil to cool off, drain the excess oil from the drain plug.
Page 154 DISASSEMBLY AND ASSEMBLY HYDRAULIC TANK Bleeding the air After replacing the hydraulic oil, bleed the air from the hy- � draulic circuit and the hydraulic units. Failure to do so may damage the hydraulic devices. Hydraulic pump 1. Loosen the air-bleeding plug (1) of the hydraulic pump.
Page 155 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP HYDRAULIC PUMP Construction � � � �� 1. Shaft 7. Gear pump 2. Swash plate 8. Housing 3. Cylinder block 9. Solenoid valve 4. Cover 10.
Page 156 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP Special tools Jig A �� Jig B �� Disassembly 1. Take out the cap screws and remove the solenoid valve from the pump. • Hold the pump upright with the shaft side on the bottom and place the pump onto the jig A so that the shaft end does not come in contact with the working table surface.
Page 157 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP 3. Remove the coupling and the bushing. �� 4. Take out the cap screw and remove the cover. • When removing, keep the cover in a level position. • Do not damage the valve plate ﬁtted on the back. •...
Page 158 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP b. Remove the plate from the shaft. �� c. Remove the guide (3), pins (5), retainer (5) and pis- � � � tons (6) from the cylinder block (7). • Do not disassemble the cylinder block (7) unless necessary.
Page 159 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP 10. Disassemble the swash plate section. �� a. Take out the cap screw and remove the plate (9). b. Remove the distance piece (10). �� c. Remove the bearing (11). � �� d. Remove the swash plate. ��...
Page 160 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP c. Remove the pin (12) and the piston (13) from the �� cylinder (14). d. For the machine with an air conditioner, remove the �� piston (15). (Only the machine with an air condition- �� ...
Page 161 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP h. Take out the spring seat and remove the O-ring from the spring seat. �� 12. Disassemble the shaft section. a. Remove the snap ring. b. Tap the shaft with a plastic hammer and remove the shaft.
Page 162 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP 14. Take out the cap screws and separate the assembly into the hydraulic pump and the pumps P3 and P4. �� 15. Disassemble the pump P4. a. Pull up the drive gear and remove the seal ring, the backup ring and the plate.
Page 163 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP c. Remove the frame. �� d. Remove the seal ring. �� e. Remove the plate, the guide and the O-rings. �� f. Remove the drive gear, the driven gear and the bushing. �� 4-58...
Page 164 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP 17. Disassemble the solenoid valve. a. Remove the ﬁlter and the O-rings. �� b. Remove the nut. c. Remove the solenoid. �� d. Remove the base. • Be careful not to drop the push rod. ��...
Page 165 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP f. Remove the plug. �� g. Remove the spring and the ball. �� 4-60...
Page 166 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP Assembly 1. Assemble the swash plate section. a. Install the swash plate on the housing. �� b. Install the bearing (11). �� c. Install the distance piece (10). d. Install the O-ring on the plate (9). ��...
Page 167 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP 5. Install the oil seal case with the oil seal. • When installing, keep the oil seal case straight. • Apply grease on the oil seal lip. 6. Install the snap ring. �� 7. Assemble the cylinder block. �...
Page 168 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP 9. Install the cylinder block by aligning it with the shaft spline. • Apply grease on the sliding surface of the piston shoe and the sliding surface against the control plate on the cylinder block. ��...
Page 169 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP f. Place the cylinder (14) in the speciﬁed position and secure it using the cap screws. Cap screw: 28 to 35 N·m �� Apply Loctite #270. �� g. Fit the O-ring to the spring seat and install the spring seat.
Page 170 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP 13. Install the relief valve. a. Install the spool (19). b. Install the spring (18). c. Fit the shim to the setscrew (17) and install it on the cover. �� d. Install the nut. •...
Page 171 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP 16. Install the coupling on the shat end of the main pump. �� 17. Assemble the pump P3. a. Engage the bushing and install the square ring (20). • Be sure to install it in the correct direction. ��...
Page 172 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP d. Install the plate that was set as above on the hous- ing. • Be sure to install the plate in the correct direc- tion. � � �� A: Discharge side B: Suction side �� e.
Page 173 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP c. Install the seal ring (21) and the backup ring (22) on the plate (23). • Apply grease on the rings to prevent them from dropping out. �� d. Install the plate on the housing. ��...
Page 174 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP g. Secure the frame and housing using the cap screws. Cap screw: 28 to 35 N·m �� h. Fit the two pins to the frame and install the coupling on the shaft end of the pump P3 side. ��...
Page 175 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP 21. Assemble the solenoid valve. a. Install the ball and the spring on the body. �� b. Install the plug. Plug: 13.2 to 17.6 N·m �� c. Install the springs and the spools on the body. ��...
Page 176 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP e. Secure the solenoids using the nuts. Nut: 4.9 N·m �� f. Install the O-rings and the ﬁlter on the body. �� 22. Connect the main pump and the gear pump and se- cure them using the cap screws. •...
Page 177 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP Inspection and adjustment Checking the parts Part Criteria Action Piston and cylinder A clearance (S) of 0.05 mm or more be- Replace block assembly tween the piston and the cylinder block assebly Replace Occurrence of scratches, scoring, ab- normal wear, etc.
Page 178 DISASSEMBLY AND ASSEMBLY HYDRAULIC PUMP Part Criteria Action Guide (1) and retainer • Check for any scorning or stepwise • Replace the guide � wear and retainer as a set, if repair is im- possible. • Repair small � scoring or scratch by lapping.
Page 179 DISASSEMBLY AND ASSEMBLY CONTROL VALVE CONTROL VALVE Construction �� 1. Tie rod 10. Arm section 2.
Page 180 DISASSEMBLY AND ASSEMBLY CONTROL VALVE Left travel section � � 1. Spring holder 2. Spring �� 3. Spring holder � 4. Cover 5. O-ring � � � � � 6. Cover 7. Poppet 8. Spring 9. O-ring 10. Plug 11.
Page 181 DISASSEMBLY AND ASSEMBLY CONTROL VALVE Boom section � � � � �� ...
Page 182 DISASSEMBLY AND ASSEMBLY CONTROL VALVE Arm section � � � � � � � � � � � 1. Spring holder 2. Spring 3. Spring holder 4. Cover 5. O-ring 6. Poppet � � � � 7. Spring � 8. O-ring ��...
Page 183 DISASSEMBLY AND ASSEMBLY CONTROL VALVE Switch valve 1. Cover 2. Spring holder �� 3. Spring holder �� 4. Spring 5. O-ring �� 6. Cover � 7. Filter 8. Poppet 9. Spring 10. O-ring 11. O-ring 12.
Page 184 DISASSEMBLY AND ASSEMBLY CONTROL VALVE 2nd auxiliary section �� 1. Cover 2. Spring holder 3. Spring holder � 4. Spring � � � � 5. Poppet 6. Spring 7. O-ring 8. O-ring 9. O-ring 10. Housing �...
Page 185 DISASSEMBLY AND ASSEMBLY CONTROL VALVE Port relief valve � � �� 1. Housing 11. Lock nut 2. Plug 12. O-ring 3. Sleeve 13. Backup ring 4. Main poppet 14, O-ring 5. Piston 15, Backup ring 6.
Page 186 DISASSEMBLY AND ASSEMBLY CONTROL VALVE Disassembly and assembly For disassembly of the control valve, follow the procedure below. For assembly of the control valve, follow the same procedure as for disassembly in the reverse order. Disassembly Valve assembly 1. Loosen the nuts (1) and remove the tie rods (2), then remove the sections.
Page 187 DISASSEMBLY AND ASSEMBLY CONTROL VALVE 5. Remove the load check valve. a. Remove the spring (3) and then the poppet (4). � � �� 6. Remove the load check valve. � a. Take out the plug (3) and spring (4) and remove the poppet (5).
Page 188 DISASSEMBLY AND ASSEMBLY CONTROL VALVE Pilot operated section � 1. Remove the cap screws and cover (1), and then re- � move the O-ring from the cover (1). Cap screw: 8.8 to 10.8 N·m � � 2. Remove the spring holder (2), spring (3) and spring holder (4).
Page 189 DISASSEMBLY AND ASSEMBLY CONTROL VALVE Main relief valve � 1. Remove the plug (1) from the housing (2). Plug: 49 to 54 N·m 2. Remove the O-ring (3) from the plug (1). � � �� 3. Remove the sleeve (4) from the plug (1), and then re- �...
Page 190 DISASSEMBLY AND ASSEMBLY CONTROL VALVE Inspection and adjustment Checking the parts Parts Criteria Action Housing, valve body • Scratches, rust or corrosion on the parts sliding against the • Replace spool • Scratches, rust or corrosion on the seal pocket part that •...
Page 191 DISASSEMBLY AND ASSEMBLY PILOT VALVE PILOT VALVE Construction �� 4KAC01Z 1. Casing 10. Spring seat 2. Plate 11. Washer 2 3. Spool 12. Spring 4. Plug 13. Spring 5. Push rod 14.
Page 192 DISASSEMBLY AND ASSEMBLY PILOT VALVE Special tools Unit: mm Installation jig A Quantity: 1 Material A: S45C Material B: SCM415N (carburizing hardening) 4KAC02Z Installation jig B Quantity: 2 Material B: SCM415N (carburizing hardening) 15.5 ±0.1 ±0.1 C0.5 C0.5 11.6 ±0.1 4KAC03Z Disassembly 1.
Page 193 DISASSEMBLY AND ASSEMBLY PILOT VALVE 3. Take out the plug (5) and remove the push rod (6) from the plug (5). • If it is hard to remove, use a ﬂat-bladed screw- driver. • Watch out for the plug popping out due to spring pressure.
Page 194 DISASSEMBLY AND ASSEMBLY PILOT VALVE 7. Remove the spring seat (14), the spring (15) and the washer 2 (16) from the spool (17). 4KAC11Z Assembly 1. Assemble the reducing valve (12). a. Install the washer 2 (16), the spring (15) and the spring seat (14) on the spool (17).
Page 195 DISASSEMBLY AND ASSEMBLY PILOT VALVE 3. Fit the O-ring (7) and the seal (8) to the plug (5). 4KAC12Z 4. Install the push rod (9) on the plug (5). • Apply hydraulic oil to the push rod 4KAC14Z 4KAC13Z 5. Install the plug (5), the plate (4) and the joint. •...
Page 196 DISASSEMBLY AND ASSEMBLY PILOT VALVE Grease the rotating part of the joint and its contact surfaces with the disc and the push rod. 4KAC15Z 4-91...
Page 197 DISASSEMBLY AND ASSEMBLY PILOT VALVE Inspection and adjustment Checking the parts Part Criteria Action O-ring — • Replace Seal — • Replace Spool • Wear on the sliding portions is 10 μm or greater com- • Replace pared to the non-sliding portions. •...
Page 198 DISASSEMBLY AND ASSEMBLY PROPORTIONAL CONTROL SOLENOID VALVE PROPORTIONAL CONTROL SOLENOID VALVE Construction � � �� 1. Proportional control solenoid 2. Spool 4-93...
Page 199 DISASSEMBLY AND ASSEMBLY PROPORTIONAL CONTROL SOLENOID VALVE Disassembly For disassembly of the proportional control solenoid valve, follow the procedure below. For assembly of the propor- tional control solenoid valve, follow the same procedure as for disassembly in the reverse order. 1.
Page 200 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) PILOT VALVE (AUXILIARY) Construction �� 1. Case 9. Spring seat 2. Cover 10. Washer 3. Plug 11. Spring 4.
Page 201 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) Special tool (for removal of bush) �� Disassembly 1. Wash the pilot valve with detergent. • Cover each port with a blank plug. 2. Insert a cushion plate between the pilot valve and the vise, and secure the pilot valve.
Page 202 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) 5. Remove the cam. • Treat the cam and ball bearing as an integral assem- bly (cannot be taken apart). • Note down the position of the cam relative to the cover. �� 6. Loosen the cap screws with a hexagon spanner and remove them.
Page 203 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) 9. Remove the pressure reducing valve assemblies and the return springs from the casing. • Note down the positions relative to the casing hole. �� 10. Place the cover sideways on a ﬂat surface, and remove the bush by applying the special jig and tapping it light- ly with a hammer.
Page 204 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) 12. Separate the spool, secondary pressure spring, shim and washer. • When assembling, use the same set of parts as above. • The washer is for adjusting the preset value of the secondary pressure spring, and its thickness differs for each spool assembly.
Page 205 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) Assembly 1. Install the wire, shim, secondary pressure spring and spring seat on the spool, in that order. • The washer is for adjusting the preset value of the secondary pressure spring, and its thickness differs for each spool assembly.
Page 206 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) 5. Install the O-ring on the plug. �� 6. Install the packing on the plug. • Make sure that the packing is not installed in the wrong way around. • Apply a thin layer of grease to the packing before installation.
Page 207 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) 9. Place the cover sideways on a ﬂat surface, and press ﬁt the bushing by using the special jig and tapping it lightly with a hammer. • Take care that the end of the bush does not pop out of the cover.
Page 208 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) 13. Insert the cam shaft while holding down the cam. Apply grease to the sliding parts of the cam shaft bearing. �� 14. Apply Loctite to the hexagon setscrew. Hexagon setscrew: Loctite #241 or equivalent ��...
Page 209 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) 17. After attaching the upper end of the bellows to the cam, insert the lower end into the groove of the cover. • Before inserting the lower end of the bellows into the groove of the cover, spray the inside of the bellows with rust-inhibiting oil.
Page 210 DISASSEMBLY AND ASSEMBLY PILOT VALVE (AUXILIARY) Inspection and adjustment Checking the parts Part Criteria Action O-ring — • Replace Seal — • Replace Spool • Wear on the sliding portions is 10 μm or greater com- • Replace pared to the non-sliding portions. •...
Page 211 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) PILOT VALVE (TRAVEL) Construction �� 1. Case 9. Spring seat 17. O-ring 2.
Page 212 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) Special tools (for bush removal) Disassembly 1. Wash the pilot valve with detergent. • Cover each port with a blank plug. �� 2. Insert a cushion plate between the pilot valve and the vise, and then secure the pilot valve.
Page 213 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 5. Remove the cam. • Handle the cam and ball bearing as an integral as- sembly (cannot be taken apart). • Note down the position of the cam relative to the cover. WARNING When removing the cam, there is a risk that the push rod (214) may pop out.
Page 214 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 8. Remove the upper casing assembly and ﬁx it in a vise. • Note down the relative position of the upper casing assembly so that it can be installed in the position it was in before disassembly. 9.
Page 215 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 12. Remove the damping spring from the casing • Note down the position of the damping spring rela- tive to the casing hole. �� 13. Pull out the spring seats from the casing by using twee- zers or the like.
Page 216 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 16. Remove the pressure reducing valve assemblies and the return springs from the casing. • Note down the positions relative to the casing hole. �� 17. Place the cover sideways on a ﬂat surface, and remove the bushing by applying the special jig and tapping it lightly with a hammer.
Page 217 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 19. Separate the spool, secondary pressure spring, shim and washer. • When assembling, use the same set of parts as above. • The washer is for adjusting the preset value of the secondary pressure spring, and its thickness differs for each spool assembly.
Page 218 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) Assembly 1. Install the wire, shim, secondary pressure spring and spring seat on the spool, in this order. • The washer is for adjusting the preset value of the secondary pressure spring and for adjusting the spool assembly;...
Page 219 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 5. Install the O-rings in the casing. �� 6. Secure the upper casing in a vise and install the balls. �� 7. Install the spring seats with tweezers or the like in the casing. •...
Page 220 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 9. Install the pistons. • Install the pistons in the positions they were in be- fore disassembly. �� 10. Install the O-ring on the plug. �� 11. Install the packing on the plug. • Be sure to install the packing in the correct direc- tion.
Page 221 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 13. Install the push rod on the plug. • Apply hydraulic oil to the push rod before installing • Do not use excessive force to insert he push rod to prevent the packing lip from damage. ��...
Page 222 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 17. Install the cover in the casing. • Install the cover in the position it was in before dis- assembly. • Take care that the cover is not lifted by the damping spring. �� 18.
Page 223 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 21. Apply Loctite to the surface of the hexagon setscrew. Hexagon setscrew: Loctite #241 �� 22. Tighten the hexagon setscrew with the speciﬁed torque. Hexagon setscrew 6.9 ±1 N∙m �� 23. Tilt the cam and apply grease to the head of the push road, and ﬁll grease into the grease cup of the plug.
Page 224 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) 24. After attaching the upper end of the bellows to the cam, insert the lower end into the groove of the cover. • Before inserting the lower end of the bellows into the groove of the cover, spray the inside of the bellows with rust-inhibiting oil.
Page 225 DISASSEMBLY AND ASSEMBLY PILOT VALVE (TRAVEL) Inspection and adjustment Checking the parts Part Criteria Action O-ring — • Replace Seal — • Replace Spool • Wear on the sliding portions is 10 μm or greater com- • Replace pared to the non-sliding portions. •...
Page 226 DISASSEMBLY AND ASSEMBLY SOLENOID VALVE (1-SECTION) SOLENOID VALVE (1-SECTION) Construction � � � � � � � � � � �� 1. Plug 2. Solenoid valve 3. O-ring 4. O-ring 5. Spring 6. Spool 7. Body 4-121...
Page 227 DISASSEMBLY AND ASSEMBLY SOLENOID VALVE (1-SECTION) Disassembly 1. Take out the cap screws and remove the solenoid coil (1). � • Place alignment marks on the solenoid and the body for easy reassembly. • Take care not to let the push rod drop out. Cap screw: 4.9 N·m 2.
Page 228 DISASSEMBLY AND ASSEMBLY SOLENOID VALVE (1-SECTION) Inspection and adjustment Checking the parts Part Criteria Action Coil • When the solenoid is burned or short-circuited, or has a wire break • Replace • Wiring short-circuit or wire break • Replace Body •...
Page 229 DISASSEMBLY AND ASSEMBLY SOLENOID VALVE (2-SECTION) SOLENOID VALVE (2-SECTION) Construction � � � � � � � � � � �� 1. Plug 2. Solenoid valve 3. O-ring 4. O-ring 5.
Page 230 DISASSEMBLY AND ASSEMBLY SOLENOID VALVE (2-SECTION) Disassembly 1. Take out the cap screws and remove the solenoid coil (1). � • Place alignment marks on the solenoid and the body for easy reassembly. • Take care not to let the push rod drop out. Cap screw: 3.92 N·m 2.
Page 231 DISASSEMBLY AND ASSEMBLY SOLENOID VALVE (2-SECTION) Inspection and adjustment Checking the parts Part Criteria Action Coil • When the solenoid is burned, short-circuited, or has a wire break • Replace • Wiring short-circuit or wire break • Replace Body • Scratches, rust, or corrosion at the sliding parts and the spool •...
Page 232 DISASSEMBLY AND ASSEMBLY CYLINDERS CYLINDERS Construction Boom cylinder � �� 1.
Page 233 DISASSEMBLY AND ASSEMBLY CYLINDERS Bucket cylinder �� 1. Piston packing 9. Tube 17. Bushing 2. Rod packing 10.
Page 234 DISASSEMBLY AND ASSEMBLY CYLINDERS Swing cylinder �� 1. Rod Packing 11.
Page 235 DISASSEMBLY AND ASSEMBLY CYLINDERS Special tools Unit: mm Installation jig B Quantity: 1 Material: SS41 Boom 64 (74) 49.8 (59.8) 70 (80) 49.8 Bucket 44.8 Blade 54.8 Swing 44.8 4LAA03Z Figures in ( ) refer to the head side. Sliding jig C +0.5 Quantity: 1 Material: STKM13C...
Page 236 DISASSEMBLY AND ASSEMBLY CYLINDERS This chapter describes mainly the procedure for the swing cylinder. When disassembling/assembling a cylinder, check its construction against the construction diagram on the preceding page. Disassembly Cylinder assembly 1. Keep the cylinder in a level position by securing the clevis of the tube in a vise and placing a wooden sup- port under the other end.
Page 237 DISASSEMBLY AND ASSEMBLY CYLINDERS 2. Remove the piston. � � <Boom cylinder arm cylinder swing cylinder> a. Take out the setscrew (1) and remove the ball (2). � • The setscrew (1) is caulked in two places with a punch. Grind off the caulked portions with a hand drill.
Page 238 DISASSEMBLY AND ASSEMBLY CYLINDERS <Boom cylinder, arm cylinder> 3. Remove the holder assembly. �� 4. Remove the rod cover assembly. 4LAA13Z <Swing cylinder> 5. Separate the retainer (9) from the rod cover. �� a. Remove the stopper (10). b. Remove the connector (11), and then disconnect the retainer (8) from the rod cover.
Page 239 DISASSEMBLY AND ASSEMBLY CYLINDERS Holder <Boom cylinder, arm cylinder> 1. Remove the O-ring (1) and the backup ring (2). � 2. Remove the collar (3), cushion seal (4) and spacer (5). � � � � �� Retainer � <Swing cylinder> �...
Page 240 DISASSEMBLY AND ASSEMBLY CYLINDERS <Bucket cylinder, blade cylinder> �� a. Remove the snap ring (24). b. Remove the rod packing holder (25), the rod pack- �� ing (22) and the backup ring (23). �� 3. Remove the dust seal (26). •...
Page 241 DISASSEMBLY AND ASSEMBLY CYLINDERS Assembly Clevis 1. Using the installation jig B, press ﬁt the bushings (28) into the piston rod and tube. 4LAA24Z 2. Install the dust seal by using the supporting metal (29). 4LAA25Z Rod cover 1. Install the rod packing. <Boom cylinder, arm cylinder, swing cylinder>...
Page 242 DISASSEMBLY AND ASSEMBLY CYLINDERS 2. Install the dust seal (26). • For a dust seal with a metal ring around its perim- eter, use a supporting metal (30) for installation. 4LAA26Z 3. Install the backup ring (22) and the O-rings (20) and (21).
Page 243 DISASSEMBLY AND ASSEMBLY CYLINDERS Piston, piston packing holder 1. Install the piston packing on the piston. <Boom cylinder, arm cylinder, swing cylinder> a. Install the O-ring (34). • If the O-ring is twisted after ﬁtted, correct it. 4LAA29Z b. Cover the piston with the sliding jig C, and then, using the ﬁtting jig D, quickly insert the slipper ring (35).
Page 244 DISASSEMBLY AND ASSEMBLY CYLINDERS 2. Install the wear ring (10). • Spread the wear ring (10) just enough so that it can be installed on the piston in axial direction. 4LAA16Z Piston rod assembly <Swing cylinder> �� 1. Install the retainer (9) on the rod cover. a.
Page 245 DISASSEMBLY AND ASSEMBLY CYLINDERS 4. Install the piston on the piston rod. <Arm cylinder> a. Install the cushion seal (8). b. First, push the cushion bearing (6) in all the way. � Then, install the stopper (7) and pull the cushion bearing back again.
Page 246 DISASSEMBLY AND ASSEMBLY CYLINDERS Cylinder assembly 1. Secure the tube in a level position, and insert the piston rod assembly into the tube. • When inserting, align the center of the piston rod with the center of the tube. Insert the assembly straight so as not to damage the seal.
Page 247 DISASSEMBLY AND ASSEMBLY CYLINDERS Inspection and adjustment Inspection after disassembly Clean each part thoroughly with cleaning oil, then carry out the following checks. When a cylinder has been disassem- bled, replace all the seals with new ones. 1. Piston rod •...
Page 248 DISASSEMBLY AND ASSEMBLY CYLINDERS Inspection after assembly No load operation test 1. Place the cylinder in a horizontal position with no load. 2. Apply gentle pressure alternately to the ports at both ends, operating the piston rod 5 or 6 times. 3.
Page 249 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR TRAVEL MOTOR Construction Hydraulic motor � � �� ...
Page 250 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR Reduction gears � �� 1.
Page 251 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR Counterbalance valve, 2nd-speed control valve, relief block assembly � � � �� ...
Page 252 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR For assembly of the counter balance valve and the hydrau- lic motor, follow the procedure below. For disassembly, follow the same procedure as for assembly in the reverse order by referring to the construction diagram. Assembly Counter balance valve and hydraulic motor 1.
Page 253 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR 4. Install the spool (19), spring (5) and spool (20) on the spool (4). 5. Install the 2nd speed spool (4) on the body. �� 6. Install the O-ring on the plug, and then attach the plug to the valve body by tightening it.
Page 254 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR 9. Install the O-rings (large and small) on the valve body. �� 10. Press ﬁt the oil seal in the ﬂange holder. • Do not disassemble the oil seal unless necessary. Add grease between the lips of the oil seal. ��...
Page 255 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR 13. Install the shaft on the ﬂange holder. • The bearing is press-ﬁtted and thus it cannot be dis- assembled. • Be careful not to damage the oil seal with the shaft. �� 14. Install the balls and the swash plate on the ﬂange hold- •...
Page 256 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR 17. Install the piston (12) and guide (13) on the shoe holder �� (11) to make the shoe holder assembly. �� 18. Install the shoe holder assembly on the cylinder block to make the cylinder block assembly. ��...
Page 257 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR 21. Install the two O-rings and two backup rings on the brake piston. • Install the O-rings inside and the backup rings out- side. �� 22. Install the brake piston assembly on the ﬂange holder. Apply grease to the O-rings, and make sure that the seal material is not caught.
Page 258 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR 25. Secure the hydraulic motor in a vise and tighten the screws. Screw: 51 to 64.7 N·m • Insert an aluminum plate or the like between the ﬂange holder and the vise to prevent the outer sur- face of the valve body from being damaged.
Page 259 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR 4. Assemble the housing and the hydraulic motor and se- cure them with a snap ring. • Fix the reduction gear and the ﬂange holder with a C clamp or a hydraulic press, and secure them with a snap ring.
Page 260 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR 9. Install the carrier 2 assembly on the housing. �� 10. Install the O-ring on the housing. 11. Add 1.0 L lubricant. �� 12. Mount the ring on the cover. Apply grease. �� 13. Install the cover on the housing. •...
Page 261 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR 14. Mount the snap ring and secure the cover. • Set a ﬂat head screwdriver to the edge of the snap ring and hammer it in around its circumference. �� 15. Mount an O-ring on the plug (G3/8) and install it on the cover.
Page 262 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR Inspection and adjustment Use limit for parts Part Area checked Judgment criteria Treatment Floating seal Sliding surface Abnormal scratches, wear or scorch- Replace ing on the surface Angular bearing Rolling surface Abnormal scratches, wear or ﬂaking Replace on the ball or race.
Page 263 DISASSEMBLY AND ASSEMBLY TRAVEL MOTOR Part Area checked Judgment criteria Treatment Valve body Sliding surface with the spool Abnormal scratches, wear or scorch- Replace both valve ing on the surface body and spool. Spool Sliding surface with the valve body Abnormal scratches, wear or scorch- ing on the surfaces Sliding surface with the check valve...
Page 264 DISASSEMBLY AND ASSEMBLY SLEW MOTOR SLEW MOTOR Construction Hydraulic motor � �� 1. O-ring 10.
Page 265 DISASSEMBLY AND ASSEMBLY SLEW MOTOR Reduction gears �� 1. Plate 11. Thrust wire 21.
Page 266 DISASSEMBLY AND ASSEMBLY SLEW MOTOR Brake valve �� ...
Page 267 DISASSEMBLY AND ASSEMBLY SLEW MOTOR Special tools Oil seal press ﬁtting jig A �� Collar installation jig B �� 4-162...
Page 268 DISASSEMBLY AND ASSEMBLY SLEW MOTOR Disassembly Slew motor 1. Take out the cap screws and remove the anti-rebound valve. �� 2. Remove the cap screws to disassemble the motor into the hydraulic motor (1) and the reduction gears (2). • Place alignment marks on the hydraulic motor and the reduction gears for easy reassembly.
Page 269 DISASSEMBLY AND ASSEMBLY SLEW MOTOR 4. Disassemble the check valve. � �� a. Remove the plug (9). �� b. Remove the spring (10) and the check valve (11). �� 5. Loosen the plug (12) and remove the relief valve. •...
Page 270 DISASSEMBLY AND ASSEMBLY SLEW MOTOR 8. Remove the cylinder block (18) and the disc (19). �� 9. Remove the shoe holder (20) and the piston assembly �� (21) from the cylinder block. 10. Remove the guide (22) and pin (23) from the cylinder block.
Page 271 DISASSEMBLY AND ASSEMBLY SLEW MOTOR 14 Disassemble the timing valve. �� a. Remove the plug (30). �� b. Remove the spring (31), washer (32) and the spool �� (33). �� c. Remove the sleeve (34). �� Reduction gears � �...
Page 272 DISASSEMBLY AND ASSEMBLY SLEW MOTOR 7. Take out the cap screws, and then remove the thrust �� place (14) from the carrier 2 (13). • Secure the carrier 2 in a vise. • The cap screws are locked with Loctite. Warm up the screws for easy removal (using a portable dryer, for example).
Page 273 DISASSEMBLY AND ASSEMBLY SLEW MOTOR 11. Remove the inner race of the bearing (20). �� • A removed oil seal cannot be reused. • Be careful not to damage the outer race of the bear- ing. 12. Remove the oil seal (21). •...
Page 274 DISASSEMBLY AND ASSEMBLY SLEW MOTOR Assembly � Anti-rebound valve � 1. Install the oriﬁce (7), washer (8) and ﬁlter (9) on the valve � body. • Use a new ﬁlter. Oriﬁce: 4.9 N·m �� 2. Install the oriﬁce (6) on the body. �...
Page 275 DISASSEMBLY AND ASSEMBLY SLEW MOTOR Brake valve and hydraulic motor 1. Install the relief valve assembly. • Tighten the plug (12). Plug: 157±10 N·m �� 2. Install the check valve assembly (11) and spring (10) on � �� the housing.
Page 276 DISASSEMBLY AND ASSEMBLY SLEW MOTOR 6. Install the pin (23) on the cylinder block. �� Apply grease to the pin beforehand. 7. Install the guide (22). 8. Attach the piston assembly (21) on the shoe holder (2) and install them on the cylinder block.
Page 277 DISASSEMBLY AND ASSEMBLY SLEW MOTOR 13. Install the spring seats (16) and the disc spring (15) on �� the housing. �� 14. Install the O-ring (14) on the housing. �� 15. Install the pin (8), bearing (6) and O-ring (7) on the cov- �...
Page 278 DISASSEMBLY AND ASSEMBLY SLEW MOTOR Reduction gears 1. Press ﬁt the oil seal (13). Apply grease on the perimeter and the mount of the oil seal beforehand. • Use press ﬁtting jig A. • Dimension of the oil seal press-ﬁtted: 4.25 mm ��...
Page 279 DISASSEMBLY AND ASSEMBLY SLEW MOTOR 6. Install the inner race (17), needle (16) and planetary gear B (15) on the carrier 2 (13). �� 7. Install the thrust plate (14) on the carrier 2 (13) and ��...
Page 280 DISASSEMBLY AND ASSEMBLY SLEW MOTOR 10. Install the carrier 1 (8). 11. Install the thrust washer (7), inner race (6), needle (5), planetary gear A (4), drive gear (4) and thrust plate (2) on the carrier 1 (8). 12. Install the O-ring (1) on the housing. Slew motor 1.
Page 281 DISASSEMBLY AND ASSEMBLY SLEW MOTOR Inspection and adjustment Use limit for parts Brake valve Part Judgment criteria Treatment Check valve, piston • Deep scratches on sliding surfaces or severe roughness • Replace • Clearance with the body is too large •...
Page 282 DISASSEMBLY AND ASSEMBLY SLEW MOTOR Reduction gears Part Judgment criteria Treatment Drive gear • Gear teeth surfaces show pitting, peeling, etc. • Replace • Excessive clearance with the motor joint due to wear of the • Replace Housing, internal gear spline Planetary gear •...
Page 283 DISASSEMBLY AND ASSEMBLY SWIVEL JOINT SWIVEL JOINT Construction �� 1. Shaft 8. O-ring 2. Hub 9. Backup ring 3. Flange 10. Dust seal 4. Thrust ring 11. Snap ring 5.
Page 284 DISASSEMBLY AND ASSEMBLY SWIVEL JOINT For disassembly of the swivel joint, follow the procedure below. For assembly of the swivel joint, follow the same procedure as for disassembly in the reverse order. Disassembly � 1. Take out the bolts and remove the hub from the ﬂange (1).
Page 285 DISASSEMBLY AND ASSEMBLY SWIVEL JOINT 5. Remove the seals from the inside diameter of the hub. • Check the positions of the seals in the construction diagram. • Remove the O-rings with an eyeleteer or similar tool with a sharp point on the end. •...
Page 286 DISASSEMBLY AND ASSEMBLY SWIVEL JOINT Inspection and adjustment Inspection procedure and treatment Inspection interval Inspection point Inspection procedure Treatment 2000 hours Seals preventing leakage Check if oil is leaking out If there is a leak, replace the O- of oil to the outside rings 4000 hours All seals...
Page 287 DISASSEMBLY AND ASSEMBLY SWIVEL JOINT Inspection after assembly After assembly, perform a leak test using the apparatus shown in the ﬁgure on each circuit. � � � � � � �� 1. Connect the pipe (3) coming from the hydraulic pump (2) to the shaft (1) side port.
Page 288 DISASSEMBLY AND ASSEMBLY AIR CONDITIONER AIR CONDITIONER Construction �� 1. Upper case 8. Unit case 2. Heater core 9. Sensor holder 3. Retainer 10.
Page 289 DISASSEMBLY AND ASSEMBLY AIR CONDITIONER 1. Removing the upper case a. Remove the three screws (5 x 12). b. Remove the 11 clamps (4) with a ﬂat head screw- driver. � �� c. Remove the upper case by pulling it upward. 2.
Page 290 DISASSEMBLY AND ASSEMBLY AIR CONDITIONER d. Install the evaporator (7) in the unit case (8), aligning � the thermistor code with the position of (C). � � �� 4. Replacing the expansion valve a. Remove the nuts from the expansion valve (11) inlet ��...
Page 291 For cases that require a special tools or instru- ments, such as for adding refrigerant gas, consult Takeuchi or your service or sales dealer for assistance. Run the air conditioner 2 to 3 times a month during the season when it is not in use to prevent the oil from drying up in the compressor.
Page 292 TROUBLESHOOTING Overall machine ................................5-3 No operation is possible............................5-3 All systems working, but insufﬁcient power....................... 5-4 Boom, bucket, slew and arm fail to move or are too slow..................5-6 Traveling ..................................5-8 Right or left travel is impossible ..........................5-8 Right or left travel speed drops causing the machine to veer to one side ..............
Page 293 TROUBLESHOOTING This “Troubleshooting” section describes the fault diagnosis and corrective actions mainly for hydraulic systems. The cause of the problem can be investigated by following the arrows in the chart shown at the beginning of each item. Notes on troubleshooting and servicing 1.
Page 294 TROUBLESHOOTING OVERALL MACHINE OVERALL MACHINE No operation is possible. Insufﬁcient Check the hydraulic oil Add hydraulic oil. level Sufﬁcient • Repair or replace the hy- Faulty Check hydraulic draulic pump. pump • Replace the coupling. 1. Check the hydraulic oil level. Check the hydraulic oil tank level.
Page 295 TROUBLESHOOTING OVERALL MACHINE All systems working, but insufﬁcient force. Insufﬁcient Check the hydraulic oil Add hydraulic oil. level Sufﬁcient Abnormal noise from the Replace the seal tape, O-ring Suction line faulty piston pump and hose. Action appropriate to the Frothing in the tank cause of the frothing.
Page 296 TROUBLESHOOTING OVERALL MACHINE 4. Check the main relief valve. Measure the relief pressure of the main relief valve. • If the measured value is within speciﬁcations, the valve is normal. “2. Service data, Performance criteria” If the pressure of the main relief valve is low, adjust it to the set pressure by gradually tightening the set- screw.
Page 297 TROUBLESHOOTING OVERALL MACHINE Boom, bucket, slew and arm fail to move or are too slow. • Repair or replace the gear Faulty Check the gear pump pump • Replace the coupling Normal Faulty Check the fuse Replace the fuse Normal Faulty Adjust or replace the limit Check the limit switch...
Page 298 TROUBLESHOOTING OVERALL MACHINE 2. Check the fuse Check the fuse in the power supply circuit that oper- ates the pilot solenoid valve. �� 3. Check the limit switch �� Turn the limit switch on, by moving the lever stand to the driving position.
Page 299 TROUBLESHOOTING TRAVELING TRAVELING Right or left travel is impossible Check the operation of actuators other than of the travel motor Normal Faulty Check the pilot valve Repair or replace the pilot (Travel) valve (travel) Normal Faulty Check the spool opera- Repair or replace the housing tion block...
Page 300 TROUBLESHOOTING TRAVELING 3. Check the spool operation Disconnect the hose connecting the control valve (trav- �� el block) and the swivel joint from the control valve. Fit the pressure gauge to the discharge port on the con- �� trol valve. •...
Page 301 TROUBLESHOOTING TRAVELING Right or left travel speed decelerates, causing the machine to veer to one side Within specs veering within Problem is caused by the Normal specs? combination of devices Out-of-specs Check the crawler belt Adjust to the speciﬁed crawler Faulty tension.
Page 302 TROUBLESHOOTING TRAVELING 1. Is the veering within specs? If the veering is within speciﬁcations, the machine is normal. Problem is caused by the combination of de- vices. “2. Service data, Performance criteria” 2. Check the crawler tension “2. Service data, Performance criteria” 3.
Page 303 TROUBLESHOOTING TRAVELING 2nd speed travel is not possible Faulty Repair or replace the gear Check the gear pump pump Normal Faulty Check the pilot relief Adjust, repair or replace the valve pilot relief valve Normal Faulty Check the fuse Replace the fuse Normal Faulty Check the 2nd speed...
Page 304 TROUBLESHOOTING TRAVELING 2. Check the pilot relief valve Measure the relief pressure of the pilot relief valve. • If the measured value is within speciﬁcations, the pi- lot relief valve is normal. “2. Service data, Performance criteria” 3. Check the fuse Check the fuse in the power supply circuit that acti- vates the 2nd speed solenoid valve.
Page 305 TROUBLESHOOTING TRAVELING 6. Check the 2nd speed solenoid valve a. Turn the starter switch to the ON position. b. Lightly press down the protruding part on the sole- noid end. c. Move the lever stand to turn on the limit switch. d.
Page 306 TROUBLESHOOTING SLEWING SLEWING No slewing is possible Check the operation of actuators other than of the slew motor Normal Faulty Repair or replace the pilot Check the pilot valve valve Normal Faulty Check the spool opera- Repair or replace the housing tion block Normal...
Page 307 TROUBLESHOOTING SLEWING 2. Check the pilot valve Disconnect the hose connecting the pilot valve and the control valve (slew block) from the control valve. Fit the pressure gauge to the hose just disconnected. • Insert a plug into the control valve port. •...
Page 308 TROUBLESHOOTING SLEWING Slew right or left is not possible Faulty Repair or replace the pilot Check the pilot valve valve Normal Faulty Check the spool opera- Repair or replace the housing tion block Normal Faulty Check the slew relief Repair or replace the slew re- valve lief valve Normal...
Page 309 TROUBLESHOOTING SLEWING 4. Check the check valve of the slew brake valve If foreign matter is caught in one of the check valves (1), or if the valve is sticking, right or left slewing does not work. • If foreign matter is caught in one of the check valves, �...
Page 310 TROUBLESHOOTING SLEWING Slewing is slow or lacks force Within specs Is the time needed for Normal slewing within specs? Slow Faulty Repair or replace the pilot Check the pilot valve valve Normal Faulty Check the spool opera- Repair or replace the housing tion block Normal...
Page 311 TROUBLESHOOTING SLEWING 1. Is the time needed for slewing within speciﬁca- tions? “2. Service data, Performance criteria” 2. Check the pilot valve “5-16” 3. Check the spool operation “5-16” 4. Check the slew pressure “5-16” 5. Check the check valve of the slew brake valve “5-18”...
Page 312 TROUBLESHOOTING SLEWING The machine slews, but overruns a lot when slewing stops, or slewing cannot be stopped Is the amount of overrun Within specs when slewing stops with- Normal in specs? Out-of-specs Faulty Repair or replace the pilot Check the pilot valve valve Normal Faulty...
Page 313 TROUBLESHOOTING SLEWING 3. Check the spool operation Check if the spool of the control valve (slew block) re- turns to the neutral position when the operation lever � (slew) is released after operation. Disconnect the hose connecting the control valve (slew block) and the slew �...
Page 314 TROUBLESHOOTING SLEWING When stopped on a slope, the upperstructure cannot maintain its posture Within specs Is the slew spontaneous Normal drop within specs? Out-of-specs Adjust the relief valve Pressure too low Check the slew pressure pressure of the slew brake Adjust to set pressure valve Normal...
Page 315 TROUBLESHOOTING BOOM BOOM The boom cylinder does not move Check the operation of actuators other than of the boom cylinder Normal Faulty Repair or replace the pilot Check the pilot valve valve Normal Faulty Check the spool opera- Repair or replace the housing tion block Normal...
Page 316 TROUBLESHOOTING BOOM 2. Check the pilot valve Disconnect the hose connecting the pilot valve and the control valve (boom block) from the control valve. Fit the pressure gauge to the hose just disconnected. �� • Operate the lever (boom) and measure the pres- ��...
Page 317 TROUBLESHOOTING BOOM Boom cylinder operation is slow or lacks force Within specs Is the speed of the boom Normal cylinder within specs? Out-of-specs Faulty Repair or replace the pilot Check the pilot valve valve Normal Faulty Check the spool opera- Repair or replace the housing tion block...
Page 318 TROUBLESHOOTING BOOM 5. Check the boom cylinder Check the boom cylinder for internal leak (1) a. Completely retract the bucket cylinder and the arm cylinder. Extend the arm cylinder rod a little, and then lower the bucket end to the ground. ��...
Page 319 TROUBLESHOOTING BOOM b. Disconnect the head side hose (A) and drain oil from � � the piping. Insert a plug (2) into the hose just discon- nected. �� c. Operate the bucket to raise the machine body. If oil leaks from the cylinder piping the hose was dis- connected from while the boom cylinder rod is ex- tended, the cylinder is leaking internally.
Page 320 TROUBLESHOOTING BOOM When the boom control lever is pulled slowly, the boom drops at ﬁrst Faulty Check the load check Repair or replace the housing valve of the control valve block Normal Faulty Check for leakage inside Repair or replace the boom the boom cylinder cylinder 1.
Page 321 TROUBLESHOOTING BOOM Spontaneous drop of the boom cylinder is too large Is the spontaneous drop Within specs of the boom cylinder with- Normal in specs? Out-of-specs Faulty Check for leak inside the Repair or replace the boom boom cylinder cylinder Normal Problem solved Test by replacing the port...
Page 322 TROUBLESHOOTING Arm cylinder does not move Check the operation of actuators other than of the arm cylinder Normal Faulty Repair or replace the pilot Check the pilot valve valve Normal Faulty Check the spool opera- Repair or replace the housing tion block Normal...
Page 323 TROUBLESHOOTING 3. Check the spool operation Disconnect the arm hose connected to the pipe at the boom foot, then install a pressure gauge in the discon- nected hose. • Operate the lever (arm) and measure the pressure. • If the measured value is within the speciﬁcations, the spool is normal.
Page 324 TROUBLESHOOTING Arm cylinder operation is slow or lacks force Within spec Is the speed of the arm Normal cylinder within spec? Out-of-spec Faulty Repair or replace the pilot Check the pilot valve valve. Normal Faulty Check the spool opera- Repair or replace the housing tion block.
Page 325 TROUBLESHOOTING 5. Check for leak inside the arm cylinder a. Fully retract the bucket cylinder and the arm cylin- der, and then lower the bucket to the ground. �� b. Disconnect the two hoses connected to the cylin- � der. Insert plugs (1) into the disconnected hoses and the cylinder piping.
Page 326 TROUBLESHOOTING Spontaneous drop of the arm is too large Is the spontaneous drop Within specs of the arm cylinder within Normal specs? Out-of-specs Faulty Repair or replace the arm cyl- Check the arm cylinder inder 1. Is the spontaneous drop of the arm cylinder within specs? “2.
Page 327 TROUBLESHOOTING BUCKET BUCKET Bucket cylinder does not move or lacks force Check the operation of actuators other than of the bucket cylinder Normal Faulty Repair or replace the pilot Check the pilot valve valve Normal Faulty Check the spool opera- Repair or replace the housing tion block...
Page 328 TROUBLESHOOTING BUCKET 4. Test by replacing the port relief valve Replace the port relief valve in question with a port re- lief valve used for a normal boom. If the bucket cylinder operates normally with the replacement valve, the port relief valve used on the bucket side is faulty.
Page 329 TROUBLESHOOTING BUCKET Spontaneous drop of the bucket is too large Is the spontaneous drop Within specs of the bucket cylinder Normal within specs? Out-of-specs Faulty Check the bucket cylin- Repair or replace the bucket cylinder Normal Oil is leaking inside the control Replace the housing block valve 1.
Page 330 TROUBLESHOOTING BOOM SWING BOOM SWING Swing cylinder does not move Check the operation of actuators other than of the swing cylinder Normal Faulty Check the spool opera- Repair or replace the housing tion block Normal Faulty Check the linkage Adjust, repair or replace Normal Faulty Check the anti-cavitation...
Page 331 TROUBLESHOOTING BOOM SWING 3. Check the linkage To check the linkage, remove the R pin (2) and pin (3) used to connect the spool and the yoke (1) , and then inspect the yoke (1) movement. � � � �� 4.
Page 332: Dozer Blade
TROUBLESHOOTING DOZER BLADE DOZER BLADE Dozer blade cylinder does not move or lacks force. Check the operation of actuators other than of the dozer blade cylinder Normal Faulty Check the spool opera- Repair or replace the housing tion block Normal Faulty Check the linkage Adjust, repair or replace...
Page 333 TROUBLESHOOTING DOZER BLADE 4. Check the supply pressure of the control valve Disconnect one of the hoses connected to the control valve housing block (blade). Fit the pressure gauge to � the hose just disconnected. Operate the lever (blade) �� ...
Page 334 TROUBLESHOOTING DOZER BLADE The spontaneous drop of the dozer blade is too large, or the dozer blade cannot support the machine Is the spontaneous drop Within specs of the dozer blade within Normal specs? Out-of-specs Faulty Check for leakage inside Repair or replace the housing the dozer blade cylinder block...
Page 335 TROUBLESHOOTING DOZER BLADE c. Raise the dozer boom and apply a load on the blade. • If the machine drops while oil drains from the cylinder’s piping, the cylinder is faulty. If the machine drops even though no oil drains out, the control valve or the swivel joint is faulty.
Page 336 TROUBLESHOOTING AUXILIARY HYDRAULICS AUXILIARY HYDRAULICS Proportional control is not possible Check the operation of actuators other than of the auxiliary piping Normal Faulty Check the proportional Repair or replace the propor- controller tional controller Normal Faulty Check the proportional Repair or replace the propor- control solenoid valve tional control solenoid valve 1.
Page 337 TROUBLESHOOTING PISTON PUMP PISTON PUMP Symptoms Major causes Remedies Noise is too loud, unusual • Suction hose is crushed or suction ﬁlter • Remove the dirt and correct the crushing. sound is heard is clogged • Joint in the suction side is loose and •...
Page 338 TROUBLESHOOTING GEAR PUMP GEAR PUMP “4. Disassembly and assembly, Gear pump” Symptoms Major causes Remedies No discharging operation • Direction of rotation is incorrect • Rotate in the rated direction. • Hydraulic oil tank level is too low • Add oil to the speciﬁed level. •...
Page 339 TROUBLESHOOTING CONTROL VALVE CONTROL VALVE “4. Disassembly and assembly, Control valve” The problems are listed individually in the table below, but in reality, many problems have multiple causes. Therefore, try to check and eliminate each possible cause one at a time. Symptoms Major causes Remedies...
Page 340 TROUBLESHOOTING CONTROL VALVE Symptoms Major causes Remedies Spool’s neutral posi- • There are cases of a large oil leak inside the • Check if the cylinder drops spontaneously tion cannot be main- cylinder when it is held. If the cylinder is faulty, disas- tained (cylinder drops) semble and repair it.
Page 341 TROUBLESHOOTING PILOT VALVE PILOT VALVE “4. Disassembly and assembly, Pilot valve” Symptoms Major causes Remedies The secondary pressure • The primary pressure is insufﬁcient • Keep the sufﬁcient primary pressure. is too low • The spring is broken or worn out •...
Page 342 TROUBLESHOOTING PROPORTIONAL CONTROL SOLENOID VALVE PROPORTIONAL CONTROL SOLENOID VALVE “4. Disassembly and assembly, Proportional control solenoid valve” Symptoms Major causes Remedies Solenoid valve does not operate • Wiring short-circuit or wire break • Replace. • Coil assembly short-circuit or wire break •...
Page 343 TROUBLESHOOTING CYLINDERS CYLINDERS “4. Disassembly and assembly, Cylinder” Symptoms Major causes Remedies Oil leak from the piston rod sliding part • Foreign matter is caught in the inter- • Remove the foreign matter. (oil stays on the surface in a ring shape; nal part of the rod packing or dust this “oil ring”...
Page 344 TROUBLESHOOTING TRAVEL MOTOR TRAVEL MOTOR “4. Disassembly and assembly, Travel motor” Hydraulic motor Symptoms Major causes Remedies Motor fails to start • All the devices other than the motor and the • Check whether the speciﬁed pressure reduction gears are not working correctly is generated in the inlet port, and then check and repair each device.
Page 345 TROUBLESHOOTING TRAVEL MOTOR Parking brake Symptoms Major causes Remedies Braking force is insufﬁcient • The total thickness of three friction discs • Replace the discs. or not evenly applied and four center discs is 13.5 mm or less • Disc surface is faulty •...
Page 346 TROUBLESHOOTING SLEW MOTOR SLEW MOTOR If you notice that the noise or heat becomes unusually high, it is likely that there is a fault in the machine. If it occurs, stop the machine immediately and try to locate the faulty section. The table below shows the cause of the general problem and action to be taken when such problem occurs in the hydraulic circuits.
Page 347 TROUBLESHOOTING SLEW MOTOR Parking brake Symptoms Major causes Remedies Cannot release the • Release pressure PB and valve • Set the release pressure PB and valve switching signal brake. Brake force is switching signal pressure SH are pressure SH as speciﬁed. weak.
Page 348 TROUBLESHOOTING AIR CONDITIONER AIR CONDITIONER “4. Disassembly and assembly, Air conditioner” A The outlets temperature cannot be changed Note: 1. After completion of repair work, make sure to reinstall the connectors removed for inspection. 2. Check if there is warm water at the IN side of the water valve. 3.
Page 349 TROUBLESHOOTING AIR CONDITIONER B. Compressor clutch does not engage Note: 1. After completion of repair work, make sure to reinstall the connectors removed for inspection. 2. Checking the items marked with * is not possible unless you have added refrigerant to the system and the ambient temperature is at least 2°C.
Page 350 TROUBLESHOOTING AIR CONDITIONER C. Blower motor does not rotate Notes: 1. If the blower motor is apparently out of order, check the blower motor before checking other items listed below. 2. After completion of repair work, make sure to reinstall the connectors removed for inspection. Is the fan switch normal? The fan switch is faulty Replace the fan switch...
Page 351 TROUBLESHOOTING AIR CONDITIONER D. The air ﬂow cannot be changed Notes: 1. Before inspection, turn off the starter switch and remove the fan switch connector. 2. After completion of repair work, make sure to reinstall the connectors removed for inspection. Cannot be changed be- Cannot be changed be- Cannot be changed be-...
Page 352 ENGINE Machine model Mounted engine TB250 4TNV88...

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