Komatsu WD420-3 Wheel Dozer Bulldozer Repair Shop Manual SEBMA00500 PDF
$32.95
Komatsu WD420-3 Wheel Dozer Bulldozer Repair Shop Manual SEBMA00500 – PDF DOWNLOAD
- MACHINE MODEL SERIAL No.
WD420-3 53101 and up
Description
Komatsu WD420-3 Wheel Dozer Bulldozer Repair Shop Manual SEBMA00500 – PDF DOWNLOAD
FILE DETAILS:
Komatsu WD420-3 Wheel Dozer Bulldozer Repair Shop Manual SEBMA00500 – PDF DOWNLOAD
Language : English
Pages : 744
Downloadable : Yes
File Type : PDF
IMAGES PREVIEW OF THE MANUAL:
TABLE OF CONTENTS:
Komatsu WD420-3 Wheel Dozer Bulldozer Repair Shop Manual SEBMA00500 – PDF DOWNLOAD
- MACHINE MODEL SERIAL No.
WD420-3 53101 and up
COVER 1
CONTENTS . 2
01 GENERAL . 20
GENERAL ASSEMBLY DRAWING . 21
SPECIFICATIONS . 22
WEIGHT TABLE . 25
LIST OF LUBRICANT AND WATER 27
10 STRUCTURE AND FUNCTION 29
POWER TRAIN . 30
POWER TRAIN SYSTEM . 31
TORPUE CONVERTER,TRANSMISSION PIPING 33
TRANSMISSION HYDRAULIC SYSTEM DIAGRAM 34
TRANSMISSION HYDRAULIC CIRCUIT DIAGRAM . 35
TORQUE CONVERTER . 36
TORQUE CONVERTER OIL FILTER . 39
TRANSMISSION . 40
TRANSMISSION CONTROL VALVE . 50
TRANSMISSION SOLENOID VALVE 71
PILOT OIL FILTER . 72
DRIVE SHAFT 73
AXLE . 74
DIFFERENTIAL . 76
FINAL DRIVE 90
AXLE MOUNT,CENTER HINGE PIN 91
STEERING PIPING 92
STEERING COLUMN 93
STEERING VALVE . 94
ORBIT-ROLL VALVE .108
STOP VALVE .112
EMERGENCY STEERING PUMP 113
DIVERTER VALVE .114
BRAKE PIPING .117
BRAKE CIRCUIT DIAGRAM 118
BRAKE VALVE 119
CHARGE VALVE .124
ACCUMULATOR (FOR BRAKE) 128
SLACK ADJUSTER .129
BRAKE 132
PARKING BRAKE CONTROL 134
PARKING BRAKE 135
PARKING BRAKE SOLENOID VALVE .136
PARKING BRAKE VALVE 137
PARKING BRAKE EMERGENCY RELEASE SOLENOID VALVE .138
HYDRAULIC PIPING .139
WORK EQUIPMENT HYDRAULIC CIRCUIT DIAGRAM .140
WORK EQUIPMENT LEVER LINKAGE .141
HYDRAULIC TANK .142
HYDRAULIC PUMP .144
MAIN CONTROL VALVE .146
BLADE CONTROL VALVE 150
HYDRAULIC CYLINDER .161
BLADE LINKAGE 163
CAB 165
ROPS CAB .166
AIR CONDITIONER 167
ELECTRICAL CIRCUIT DIAGRAM .168
MACHINE MONITOR SYSTEM .172
MAIN MONITOR .173
MAINTENANCE MONITOR 177
SENSORS 179
ENGINE STARTING CIRCUIT 184
ENGINE STOP CIRCUIT 185
PREHEATING CIRCUIT 186
ELECTRIC TRANSMISSION CONTROL 187
WORK EQUIPMENT CONTROL LEVER SWITCH 190
TRANSMISSION CUT-OFF SWITCH 191
TRANSMISSION CUT-OFF FUNCTION 192
ELECTRIC PAERING BRAKY CONTROL .194
20 TESTING AND ADJUSTING .206
STANDARD VALUE TABLE FOR ENGINE 207
STANDARD VALUE TABLE FOR CHASSIS .208
STANDARD VALUE TABLE FOR ELECTRICAL PARTS 211
TOOLS FOR TESTING,ADJUSTING,AND TROUBLESHOOTING 214
ADJUSTING VALVE CLEARANCE 215
MEASURING COMPRESSION PRESSURE .216
TESTING AND ADJUSTING FUEL INJECTION TIMING 217
MEASURING EXHAUST COLOR 219
MEASURING INTAKE AIR PRESSURE (BOOST PRESSURE) .220
MEASURING BLOW-BY PRESSURE .221
TESTING AND ADJUSTING FAN BELT TENSION .222
MEASURING ENGINE SPEED .223
METHOD FOR ADJUSTING ENGINE STOP MOTOR CABLE .224
MEASURING ENGIEN OIL PRESSURE .226
MEASURING EXHAUST GAS TEMPERATURE 227
MEASURING ACCELERATOR PEDAL 228
MEASURING OPERATING FORCE,TRAVEL OF SPEED LEVER 230
MEASURING STALL SPEED 231
MEASURING TORQUE CONVERTER,TRANSMISSION,PARKING BRAKE OIL PRESSURE .233
METHOD OF OPERATING EMERGENCY MANUAL SPOOL .235
MEASURING CLEARANCE BETWEEN TIRE AND WHEEL .237
TESTING AND ADJUSTING STEERING WHEEL .238
TESTING AND ADJUSTING STEERING CONTROL .241
MEASURING STEERING OIL PRESSURE 242
MEASURING OPERATING FORCE,TRAVEL OF BRAKE PEDAL 244
MEASURING BRAKE PERFORMANCE 245
TESTING BRAKE OIL PRESSURE .246
MEASURING BRAKE DISC WEAR 247
BLEEDING AIR FROM BRAKE SYSTEM .248
MEASURING PARKING BRAKE PERFORMANCE 249
METHOD FOR MANUAL RELEASE OF PARKING BRAKE .250
TESTING WEAR OF PARKING BRAKE DISC .251
MEASURING WORK EQUIPMENT CONTROL LEVER .252
MEASURING WORK EPUIPMENT HYDRAULIC PRESSURE 254
MEASURING WORK EQUIPMENT SPEED .256
MEASURING HYDRAULIC DRIFT OF WORK EQUIPMENT CYLINDER .257
ADJUSTING MAIN MONITOR(SPEEDOMETER MODULE) .258
CHECKING FOR ABNORMALITY IN FUEL LEVEL SENSOR 259
TROUBLESHOOTING 260
POINTS TO REMEMBER WHEN RTOUBLESHOOTING 261
SEQUENCE OF EVENTS IN TROUBLESHOOTING 262
PRECAUTIONS WHEN CARRYING OUT MAINTENANCE 263
HANDLING CONNECTORS 270
CHECKS BEFORE TROUBLESHOOTING 271
METHOD OF USING TROUBLESHOOTING CHARTS .272
CONNECTOR TYPES AND MOUNTING LOCATIONS, CONNECTOR PIN ARRANGEMENT DIAGRAM 280
CONNECTOR TYPES FOR CONNECTOR PIN NUMBERS 284
TROUBLESHOOTING OF ENGINE SYSTEM (S MODE) 291
S-1 STARTING PERFORMANCE IS POOR (STATRING ALWAYS TAKES TIME) 292
S-2 ENGINE DOES NOT START 293
(1)ENGINE DOES NOT TURN 293
(2)ENGINE TURNS BUT NO EXHAUST GAS COMES OUT (FUEL IS NOT BEING INJECTED) 294
(3)EXHAUST GAS GOMES OUT BUT ENGINE DOES NOT START (FUEL IS BEING INJECTED) 295
S-3 ENGINE DOES NOT PICK UP SMOOTHLY (FOLLOW-UP IS POOR) .296
S-4 ENGINE STOPS DURING OPERATIONS .297
S-5 ENGINE DOES NOT ROTATE SMOOTHLY (HUNTING) 298
S-6 ENGINE LACKS OUTPUT (NO POWER) .299
S-7 EXHAUST GAS IS BLACK (INCOMPLETE COMBUSTION) .300
S-8 OIL CONSUMPTION IS EXCESSIVE (OR EXHAUST GAS IS BLUE) 301
S-9 OIL BECOMES CONTAMINATED QUICKLY .302
S-10 FUEL CONSUMPTION IS ESCESSIVE .303
S-11 OIL IS IN COOLING WATER,OR WATER SPURTS BACK,OR WATER LEVEL GOES DOWN .304
S-12 OIL PRESSURE LAMP LIGHTS UP (DROP IN OIL PRESSURE) 305
S-13 OIL LEVEL RISES .306
S-14 WATER TEMPRAUTRE BECOMES TOO HIGH (OVERHEATING) .307
S-15 ABNORMAL NOISE IS MADE 308
S-16 VIBRATION IS EXCESSIVE 309
TROUBLESHOOTING OF MAIN MONITOR (M MODE) .310
M-1 MAIN MONITOR DOES NOT WORK .312
M-2 WHEN STARTING SWITCH IS TURNED ON AND ENGINE IS STARTED IMMEDIATELY,ALL LAMPS STAY LIGHTED UP 313
M-3 SPEEDOMETER DISPLAY DOES NOT WORK PROPERLY .314
M-4 ABNORMALITY IN SHIFT INDICATOR .315
(a)STAYS AT N EVEN WHEN DIRECTIONAL LEVER IS AT F 315
(b)STAYS AT N EVEN WHEN DIRECTIONAL LEVER IS AT R 315
(c)DOES NOT DISPLAY N EVEN WHEN DIRECTIONAL LEVER IS AT N AND DISPLAYS R WHEN DIRECITONAL LEVER IS AT F 315
(d)DOES NOT DISPLAY N EVEN WHEN DIRECTIONAL LEVER IS AT N AND DISPLAYS F WHEN DIRECITONAL LEVER IS AT R 316
(e)DOES NOT DISPLAY 1ST,4TH 316
(f)DOES NOT DISPLAY 3RD,4TH 317
(g)DOES NOT DISPLAY 2ND,3RD 317
(h)DOES NOT DISPLAY 1ST,2ND 318
M-5 HIGH BEAM DOES NOT LIGHT UP .319
M-6 TURN SIGNAL DISPLAY DOES NOT LIGHT UP 320
(a)L.H.TURN SIGNAL DOES NOT LIGHT UP .320
(b)R.H.TRRN SIGNAL DOES NOT LIGHT UP .320
M-7 ABNORALITY IN PARKING DISPLAY 321
(a)PARKING LAMP DOES NOT LIGHT UP 321
(b)PARKING LAMP STAYS LIGHTED UP .321
M-8 ABNORMALITY IN PREHEATING SYSTEM (QGS) .322
(a)DOES NOT CARRY OUT PREHERTING 322
(b)ALWAYS CARRIES OUT PREHEATING FOR 1 MINUTE 323
(c)PREHEATING STAYS ON .323
(d)PREHEATING TIME BECOMES SHORTER,OR THERE IS VARIATION .324
M-9 NIGHT LIGHTING DOES NOT LIGHT UP .325
M-10 ABBORMALITY IN FRONT WORKING LAMP .326
(a)NEITHER MONITOR DISPLAY NOR FRONT WORKING LAMP LIGHT UP .326
(b)WORKING LAMP LIGHTSUP BUT MONITOR DISPLAY DOES NOT LIGHT UP .326
(c)MONITOR LIGHTS UP BUT WORKING LAMP DOES NOT LIGHT UP 326
M-11 ABNORMALITY IN REAR WORKING LAMP 327
(a)NEITHER MONITOR DISPLAY NOR FRONT WORKING LAMP LIGHT UP .327
(b)WORKING LAMP LIGHTSUP BUT MONITOR DISPLAY DOES NOT LIGHT UP .327
(c)MONITOR LIGHTS UP BUT WORKING LAMP DOES NOT LIGHT UP 327
M-12 ABNORMALITY IN TRANSMISSION CUT-OFF .329
(a)WHEN MONITOR SWITCH IS PRESSED,CUT-OFF FUNCTION IS NOT SWITCHED AND DISPLAY IS NOT GIVEN 329
(b)MONITOR DISPLAY GOES OUT CUT-OFF FUNCTION STAYS ON 329
(c)MONITOR DISPLAY LIGHTS UP BUT CUT-OFF FUNCTION IS NOT ACTUATEL 330
M-13 ABNORMALITY IN PARKING BRAKE DRAGGING WARNING .331
(a)WHEN PARKING BRAKE IS APPLIED,BUZZER SOUNDS(INTERMITTENTLY) EVEN WHEN DIRECITONAL LEVER IS AT N,AND CAUTION LAMP FLASHES 331
(b)WHEN PARKING BRAKE IS APPLIED,BUZZER DOES NOT SOUND AND CAUTION LAMP DOES NOT LIGHT UP EVEN WHEN DIRECTIONAL LEVER IS AT POSITION OTHER THAN N 331
M-14 WHEN PARKING BRAKE DRAGGING WARNING IS GIVEN,BUZZER AND CAUTION LAMP ARE ACTUATED CONTINUOUSLY,OR THEY ARE NOT ACTUATED .332
(a)ACTUATED CONTINUOUSLY .332
(b)NOT ACTUATED 332
M-15 ABNORMALITY IN BUZZER .333
(a)BUZZER DOES NOT SOUND WHEN STARTING SWITCH IS TURNED ON (DURING SELF-CHECK) .333
(b)BUZZER ALWAYS SOUNDS 333
M-16 CONDITION OF MONITOR SWITCHES IS NOT STORED IN MEMORY .334
M-17 ABNORMALITY IN FAILURE DISPLAY MODE .335
(a)DOES NOT ENTER FAILURE DISPLAY MODE .335
(b)TIME FOR TIME ELAPSED SINCE FAILURE ON FAILURE DISPLAY MODE DOES NOT ADVANCE 335
M-18 ABNORMALITY IN EMERGENCY STEERING MORMAL DISPLAY 336
(a)EMERGENCY STEERING NORMAL DISPLAY DOES NOT LIGHT UP .336
(b)EMERGENCY STEERING NORMAL DISPLAY STAYS LIGHTED UP 336
M-19 ABNORMALIYT IN EMERGENCY STEERING ACTUATION DISPLAY .337
(a)EMERGENCY STEERING NORMAL DISPLAY DOES NOT LIGHT UP .337
(b)EMERGENCY STEERING NORMAL DISPLAY STAYS LIGHTED UP 337
TROUBLESHOOTING OF MAINTENANCE MONITOR SYSTEM (K MODE) .338
K-1 WHEN STARTING SWITCH IS TURNED ON,ALL LAMPS ON MAINTENANCE MONITOR DO NOT LIGHT UP FOR 3 SECONDS,MAINTENANCE MONITOR DOES NOT WORK .339
(a)ALL LAMPS ON MAINTENANCE MONITOR DO NOT LIGHT UP FOR 3 SECONDS 339
(b)SOME LAMPS DO NOT LIGHT UP 340
K-2 WHEN STARTING SWITCH IS TURNED ON,ALL LAMPS ON MAINTENANCE MONITOR LIGHT UP BUT DO NOT GO OUT 340
K-3 WHEN ENGINE IS STARTED IMMEDIATELY ARTER STARTING SWITCH IS TURNED ON (WITHIN 3 SECONDS),ALL LAMPS ON MAINTENANCE MONITOR DO NOT GO DOUT .341
K-4 WHEN STARTING SWITCH IS TURNED ON (ENGINE STOPPED),CHECK ITEMS FLASH .342
(a)ENGINE OIL LEVEL DISPLAY FLASHES 342
(b)ENGINE WATER LEVEL DISPLAY FLASHES 343
K-5 WHEN STARTING SWITCH IS TURNED ON (ENGINE STARTED),CAUTION ITEMS FLASH .344
(a)ENGINE OIL LEVEL DISPLAY FLASHES 344
(b)BATTERY CHARGE LEVEL DISPLAY FLASHES 345
(c)BRAKE OIL PRESSURE DISPLAY FLASHES 346
(d)AIR CLEANER DISPLAY FLASHES .347
K-6 CAUTION ITEMS ARE FLASHING BUT ALARM BUZZER DOES NOT SOUND .348
K-7 THERE IS NO ABORMALITY IN MONITOR DISPLAY BUT ALARM BUZZER SOUNDS 349
K-8 CAUTION ITEMS ARE FLASHING BUT WARNING LAMP (CHECK LAMP,CAUTION LAMP) DOES NOT LIGHT UP 350
(a)CHECK LAMP 350
(b)CAUTION LAMP 350
K-9 THERE IS NO ABORMALITY IN MAINTENANCE MONITOR DISPLAY BUT WARNING LAMP (CHECK LAMP,CAUTION LAMP) LIGHTS UP .351
(a)CHECK LAMP 351
(b)CAUTION LAMP 351
K-10 NIGHT LIGHTING DOES NOT LIGHT UP WHEN LAMP SWITCH IS TURNED ON (ONLY LIGHTING OF MAINTENANCE MONITOR DOES NOT LIGHT UP) .352
K-11 NIGHT LIGHTING LIGHTS UP EVEN WHEN LAMP SWITCH IS OFF,NIGHT LIGHTING STAYS LIGHTED UP .353
K-12 SERVICE METER DOES NOT WORK .354
K-13 SERVICE METER IS RUNNING EVEN WHEN ENGINE IS STOPPED 354
K-14 ABNORMALITY IN GAUGE ITEMS 355
(a)ABNORMALITY IN FUEL GAUGE .355
(b)ABNORMALITY IN ENGINE WATER TEMPERATURE GAUGE .356
(c)ABNORMALITY IN TORQUE CONVERTER OIL TEMPERATURE GAUGE .357
TROUBLESHOOTING OF EVECTRICAL SYSTEM (E MODE) 358
E-1 ENGINE DOES NOT START 359
(a)STARTING MOTOR DOES NOT TURN 359
(b)STARTING MOTOR TURNS 363
E-2 ENGINE DOES NOT STOP .365
E-3 ENGINE STOPS WHEN MACHINE IS TRAVELING .365
E-4 PARKING BRAKE DOES NOT WORK 366
(a)PARKING BRAKE HAS NO EFFECT WHEN PARKING BRAKE SWITCH IS TURNED ON 366
(b)PARKING BRAKE HAS NO EFFECT WHEN BRAKE PRESSURE DROPS .366
E-5 PARKING BRAKE IS APPLIED WHEN MACHINE IS TRAVELING .367
E-6 PARKING BRAKE IS RELEASED WHEN STARTING SWITCH IS TURNED ON 369
E-7 TRANSMISSION DOES NOT CHANGE TO NEUTRAL WHEN PARKING BRAKE IS APPLIED 369
E-8 TRANSMISSION DOES NOT WORK NORMALLY 370
(a)PROBLEM IN COMMON CIRCUIT FOR TRANSMISSION (ALWAYS STAYS IN 2ND) 372
(b)PROBLEN IN H-L CIRCUIT 372
(c)PROBLEM IN SPEED CIRCUIT .373
(d)PROBLEM IN 4TH CIRCUIT (DOES NOT ENTER 4TH) .373
(e)CONTACT IN H-L CIRCUIT 374
(f)CONTACT IN SPEED CIRCUIT .376
(g)CONTACT IN 4TH CIRCUIT (ALWAYS STAYS IN 4TH) 378
(h)PROBLEM IN FORWARD CIRCUIT (REVERSE IS NORMAL) 379
(i)PROBLEM IN REVERSE CIRCUIT (FORWARD IS NORMAL) 381
(j)PROBLEM IN COMMON CIRCUIT FOR FORWARD AND REVERSE (DOES NOT TRAVEL FORWARD,PARKING BRAKE IS NORMAL) .383
(k)CONTACT IN FORWARD CIRCUIT 385
(l)CONTACT IN REVERSE CIRCUIT 387
(m)PROBLEM IN COMMON CIRCUIT FOR FORWARD AND REVERSE .389
TROUBLESHOOTING OF HYDRAULIC AND MECHANICAL SYSTEM (CHASSIS RELATED) (T MODE) 390
POWER TRAIN 391
T-1 MACHINE DOES NOT START .391
T-2 TRAVEL SPEED IS SLOW,THRUSTING POWER IS WEEK,LACKS POWER ON SLOPES .393
T-3 EXCESSIVE SHOCK WHEN STARTING MACHINE OR SHIFTING GEAR .395
T-4 EXCESSIVE TIME LAG WHEN STARTING MACHINE OR SHIFTING GEAR 396
T-5 TORQUE CONVERTER OIL TEMPERATURE IS HIGH .397
STEERING SYSTEM 398
T-6 STEERING WHEEL DOES NOT TURN .398
T-7 STEERING WHEEL IS HEAVY 399
T-8 STEERING WHEEL WOBBLES OR THERE IS EXCESSIVE SHOCK .400
T-9 MACHINE STEERS TO ONE SIDE WHEN TRAVELING 400
T-10 TURNING RADIUS TO LEFT AND RIGHT IS DIFFERENT .400
BRAKE SYSTEM .401
T-11 BRAKES DO NOT WORK OR BRAKING EFFECT IS POOR 401
T-12 BRAKES ARE NOT RELEASED OR BRAKES DRAG 402
T-13 PARKING BRAKE IS NOT RELEASED OR BRAKE DRAGS 403
WORK EQUIPMENT .404
T-14 BLADE DOES NOT RISE .404
T-15 BLADE MOVES SLOWLY OR DOES NOT HAVE SUFFICIENT LIFTING POWER 405
T-16 BLADE MOVEMENT BECOMES SLOW AFTER IT REACHES A CERTAIN HEIGHT .406
T-17 BLADE CANNOT BE HELD DOWN WITH LIFT CYLINDER 406
T-18 BLADE HAS LARGE HYDRAULIC DRIFT .406
T-19 BLADE MOVEMENT IS UNSTEADY DURING WORK 407
T-20 BLADE LOWERS MOMENTARILY WHEN CONTROL LEVER IS SHIFTED FORM “HOLD” TO “RAISE” .407
T-21 BLADE DOSE NOT PITCH 408
T-22 BLADE MOVES SLOWLY OR HAS INSUFFICIENT TILT POWER .409
T-23 EXCESSIVE HYDRAULIC DRIFT OF BLADE WHEN TILTED 410
T-24 BLADE DOES NOT PITCH 410
T-25 BLADE PITCH MOVEMENT IS SLOW OR LACKS POWER .410
30 DISASSEMBLY AND ASSEMBLY 411
METHOD OF USING MANUAL .413
PRECAUTIONS WHEN CARRYING OUT OPERATION 415
SPECISL TOOL LIST 417
STARTING MOTOR .419
REMOVAL 419
INSTALLATION .419
ALTERNATOR .420
REMOVAL 420
INSTALLATION .420
ENGINE OIL COOLER 421
REMOVAL 421
INSTALLATION .421
AFTERCOOLER CORE .422
REMOVAL 422
INSTALLATION .422
FUEL INJECTION PUMP 423
REMOVAL 423
INSTALLATION .424
WATER PUMP .425
REMOVAL 425
INSTALLATION .425
TURBOCHARGER .426
REMOVAL 426
INSTALLATION .426
NOZZLE HOLDER 427
REMOVAL 427
INSTALLATION .427
THERMOSTAT .428
REMOVAL 428
INSTALLATION .428
CYLINDER HOLDER 429
REMOVAL 429
INSTALLATION .435
RADIATOR .437
REMOVAL 437
INSTALLATION .439
ENGINE .440
REMOVAL 440
INSTALLATION .445
TORQUE CONVERTER CHARGING PUMP .446
REMOVAL 446
INSTALLATION .446
TORQUE CONVERTER,TRANSMISSION 447
REMOVAL 447
INSTALLATION .454
TORQUE CONVERTER .456
DISASSEMBLY 456
ASSEMBLY .458
TRANSMISSION .461
DISASSEMBLY 461
ASSEMBLY .466
TRANSMISSION CLUTCH PACK .472
DISASSEMBLY 472
ASSEMBLY .481
PARKING BRAKE 493
DISASSEMBLY 493
ASSEMBLY .495
TRANSMISSION CONTROL VALVE .498
REMOVAL 498
INSTALLATION .500
DISASSEMBLY .501
ASSEMBLY .506
TRANSMISSION ACCUMULATOR VALVE .512
DISASSEMBLY 512
ASSEMBLY .513
DRIVE SHAFT 514
DISASSEMBLY 514
ASSEMBLY .516
FRONT AXLE .518
REMOVAL 518
INSTALLATION .520
REAR AXLE 521
REMOVAL 521
INSTALLATION .524
FRONT DIFFERENTIAL .526
REMOVAL 526
INSTALLATION .529
REAR DIFFERENTIAL 531
REMOVAL 531
INSTALLATION .534
DIFFERENTIAL .536
DISASSEMBLY 536
ASSEMBLY .539
DIFFERENTIAL (LIMITED SLIP DIFFERENTIAL) .547
DISASSEMBLY 547
ASSEMBLY .551
DIFFERENTIAL (NOSPIN DIFFERENTIAL) .561
DISASSEMBLY 561
ASSEMBLY .565
FINAL DRIVE .573
DISASSEMBLY 573
ASSEMBLY .576
CENTER HINGE PIN .580
REMOVAL 580
INSTALLATION .588
STEERING VALVE (ORBIT-ROLL) 594
REMOVAL 594
INSTALLATION .595
STEERING VALVE .596
DISASSEMBLY 596
ASSEMBLY .599
REMOVAL 604
INSTALLATION .605
STEERING DEMAND VALVE 606
DISASSEMBLY 606
ASSEMBLY .610
STRREING,SWITCH PUMP .614
REMOVAL 614
INSTALLATION .617
STEERING CYLINDER 618
REMOVAL 618
INSTALLATION .619
BRAKE VALVE 620
REMOVAL 620
INSTALLATION .621
RIGHT BRAKE VALVE (TANDEM) .622
DISASSEMBLY 622
ASSEMBLY .623
LEFT BRAKE VALVE (SINGLE) 624
DISASSEMBLY 624
ASSEMBLY .625
SLACK ADJUSTER 626
REMOVAL 626
INSTALLATION .627
DISASSEMBLY 628
ASSEMBLY .629
BRAKE 630
DISASSEMBLY 630
ASSEMBLY .636
PARKING BRAKE DISC .644
REMOVAL 644
INSTALLATION .646
HYDRAULIC TANK .647
REMOVAL 647
INSTALLATION .649
WORK EQUIPMENT,ACCUMULATOR CHARGING PUMP .650
REMOVAL 650
INSTALLATION .653
BLADE CONTROL VALVE 654
REMOVAL 654
INSTALLATION .655
MAIN CONTROL VALVE .656
REMOVAL 656
INSTALLATION .657
DISASSEMBLY 658
ASSEMBLY .660
LIFT CYLINDER 662
REMOVAL 662
INSTALLATION .662
PITCH AND TILT CYLINDER 663
REMOVAL 663
INSTALLATION .663
LIFT,TILT,STEERING CYLINDER 664
DISASSEMBLY 664
ASSEMBLY .667
WORK EQUIPMENT .671
REMOVAL 671
INSTALLATION .674
WORK EQUIPMENT ASSEMBLY 678
DISASSEMBLY 678
ASSEMBLY .680
COUNTERWEIGHT 682
REMOVAL .682
INSTALLATION .682
FUEL TANK 683
REMOVAL 683
INSTALLATION .684
CAB 685
REMOVAL 685
INSTALLATION .686
MAIN MONITOR .687
REMOVAL 687
INSTALLATION .688
MAINTERANCE MONITOR 689
REMOVAL 689
INSTALLATION .689
AIR CONDITIONER UNIT .690
REMOVAL 690
INSTALLATION .695
AIR CONDITIONER CONDENSER 696
REMOVAL 696
INSTALLATION .697
DRY RECEIVER .698
REMOVAL 698
INSTALLATION .698
AIR CONDITIONER COMPRESSOR .699
REMOVAL 699
INSTALLATION .700
40 MAINTENANCE STANDARD 701
ENGINE MOUNT,TRANSMISSION MOUNT 702
TORQUE CONVERTER .703
TRANSMISSION .704
TRANSMISSION CONTROL VALVE .711
DRIVE SHAFT 715
DIFFERENTIAL .716
FINAL DRIVE 720
AXLE MOUNT .721
STEERING COLUMN 722
STEERING VALVE .723
STEERING CYLINDER MOUNT 724
SLACK ADJUSTER .725
BRAKE VALVE 726
BRAKE 729
PARKING BRAKE 731
TORQUE CONVERTER,TRANSMISSION PUMP .732
STRRING,SWITCH PUMP 733
HYDRAULIC,ACCUMULATOR CHARGE PUMP 734
MAIN CONTROL VALVE .735
HYDRAULIC CYLINDER 737
CENTER HINGE PIN .739
BLADE LINKAGE 741
DESCRIPTION:
Komatsu WD420-3 Wheel Dozer Bulldozer Repair Shop Manual SEBMA00500 – PDF DOWNLOAD
- MACHINE MODEL SERIAL No.
WD420-3 53101 and up
Mistakes in operation are extremely dangerous. Read the Operation and Maintenance Manual care- fully BEFORE operating the machine.
1. Before carrying out any greasing or repairs, read all the precautions given on the decals which are fixed to the machine.
2. When carrying out any operation, always wear safety shoes and helmet. Do not wear loose work clothes, or clothes with buttons missing.
• Always wear safety glasses when hitting parts with a hammer.
• Always wear safety glasses when grinding parts with a grinder, etc.
3. If welding repairs are needed, always have a trained, experienced welder carry out the work. When carrying out welding work, always wear welding gloves, apron, hand shield, cap and other clothes suited for welding work.
4. When carrying out any operation with two or more workers, always agree on the operating procedure before starting. Always inform your fellow workers before starting any step of the operation. Before starting work, hang UNDER REPAIR signs on the controls in the operator’s compartment.
5. Keep all tools in good condition and learn the correct way to use them.
machine on hard, level ground, and block the wheels or tracks to prevent the machine from moving.
8. Before starting work, lower blade, ripper, bucket
or any other work equipment to the ground. If this is not possible, insert the safety pin or use blocks to prevent the work equipment from fall- ing. In addition, be sure to lock all the control levers and hang warning signs on them. 9. When disassembling or assembling, support the machine with blocks, jacks or stands before starting work.
10. Remove all mud and oil from the steps or other places used to get on and off the machine. Always use the handrails, ladders or steps when getting on or off the machine. Never jump on or off the machine. If it is impossible to use the handrails, ladders or steps, use a stand to pro- vide safe footing.
11. When removing the oil filler cap, drain plug or hydraulic pressure measuring plugs, loosen them slowly to prevent the oil from spurting out. Before disconnecting or removing components of the oil, water or air circuits, first remove the pressure completely from the circuit.
12.The water and oil in the circuits are hot when the engine is stopped, so be careful not to get burned.
Wait for the oil and water to cool before carry- ing out any work on the oil or water circuits.
13. Before starting work, remove the leads from the battery. Always remove the lead from the nega- tive (-) terminal first.
14. When raising heavy components, use a hoist or crane.
Check that the wire rope, chains and hooks are free from damage.
Always use lifting equipment which has ample capacity.
Install the lifting equipment at the correct places. Use a hoist or crane and operate slowly to pre- vent the component from hitting any other part. Do not work with any part still raised by the hoist or crane.
15. When removing covers which are under internal
pressure or under pressure from a spring, always leave two bolts in position on opposite sides. Slowly release the pressure, then slowly loosen the bolts to remove.
16. When removing components, be careful not to break or damage the wiring. Damaged wiring may cause electrical fires.
17. When removing piping, stop the fuel or oil from spilling out. If any fuel or oil drips onto the floor, wipe it up immediately. Fuel or oil on the floor can cause you to slip, or can even start fires.
18.As a general rule, do not use gasoline to wash parts. In particular, use only the minimum of gasoline when washing electrical parts.
G.B 25/12/24
