Komatsu WA420MC-Series WA420-3MC Wheel Loader Workshop Repair Manual PDF - MKMTSWA420MC.zip
A full workshop service and repair manual featuring Electrical Wiring Diagrams for the Komatsu WA420-MC-Series Wheel Loader, packed with everything technicians need to service, troubleshoot, fix, and overhaul the machine the way professional mechanics do.
The Komatsu Wheel Loader WA420-3MC workshop service repair manual covers the following:
* Numbered table of contents easy to use so that you can find the information you need fast.
* Detailed sub-steps expand on repair procedure information
* Numbered instructions guide you through every repair procedure step by step.
* Troubleshooting and electrical service procedures are combined with detailed wiring diagrams for ease of use.
* Notes, cautions and warnings throughout each chapter pinpoint critical information.
* Bold figure number help you quickly match illustrations with instructions.
* Detailed illustrations, drawings and photos guide you through every procedure.
* Enlarged inset helps you identify and examine parts in detail.
PRODUCT DETAILS:
Total Pages: 780 pages
File Format: PDF (Internal Links, Bookmarked, Table of Contents, Searchable, Printable, high quality)
Language: English
CEBM003502 - Komatsu Wheel Loader WA420-3MC Shop Manual.pdf
MAIN MENU......0
COVER......1
CONTENTS......3
FOREWORD......15
01 GENERAL......29
SPECIFICATION DRAWINGS......30
SPECIFICATIONS......32
WEIGHT TABLE......35
PROPER SELECTION OF FUEL, COOLANT AND LUBRICANTS......36
ENGINE OIL SPECIFICATIONS......37
TRANSMISSION, TORQUE CONVERTER, TRANSFER CASE AND OIL COOLER, SERVICE BRAKES AND HYDRAULIC SYSTEM OIL SPECIFICATIONS......38
FINAL DRIVE OIL SPECIFICATIONS......38
DRIVE AXLE OIL SPECIFICATIONS......38
DIESEL FUEL SPECIFICATIONS......38
COOLANT SPECIFICATIONS......39
10 STRUCTURE AND FUNCTION......45
POWER TRAIN......47
POWER TRAIN SYSTEM......48
TORQUE CONVERTER, TRANSMISSION PIPING......50
TRANSMISSION HYDRAULIC SYSTEM DIAGRAM......52
TRANSMISSION HYDRAULIC CIRCUIT DIAGRAM......53
TORQUE CONVERTER......54
TORQUE CONVERTER OIL FILTER......57
TRANSMISSION......58
FORWARD, REVERSE CLUTCH......60
REVERSE, 2ND CLUTCH......61
3RD, 4TH CLUTCH......61
FORWARD 1ST......63
FORWARD 2ND......64
FORWARD 3RD......65
FORWARD 4TH......66
REVERSE 1ST......67
TRANSMISSION CONTROL VALVE......68
UPPER VALVE......69
LOWER VALVE......70
TRANSMISSION SOLENOID VALVE......71
FLOW VALVE......73
ACCUMULATOR VALVE......74
DIRECTIONAL SELECTOR VALVE......76
EMERGENCY MANUAL SPOOL......77
PRIORITY VALVE......78
TORQUE CONVERTER OUTLET PORT VALVE......79
PILOT REDUCING VALVE......80
PROPORTIONAL SOLENOID VALVE......81
TRANSMISSION SOLENOID VALVE......81
ELECTRONIC CONTROL MODULATION VALVE (ECMV)......82
PILOT OIL FILTER......85
DRIVE SHAFT......86
FRONT AXLE......87
REAR AXLE......88
DIFFERENTIAL......89
FRONT DIFFERENTIAL......89
REAR DIFFERENTIAL......90
TORQUE PROPORTIONING DIFFERENTIAL......92
LIMITED SLIP DIFFERENTIAL (OPTION)......93
FINAL DRIVE......96
AXLE MOUNT, CENTER HINGE PIN......97
STEERING PIPING......98
STEERING COLUMN......99
STEERING VALVE......100
OPERATION OF DEMAND VALVE......101
STEERING SPOOL OPERATED......102
FLOW AMP......104
OPERATION OF STEERING VALVE......107
TURNING RIGHT......108
TURNING LEFT......109
STEERING RELIEF VALVE......110
OPERATION OF RELIEF VALVE......111
SAFETY VALVE (WITH SUCTION)......112
ORBIT-ROLL VALVE......114
CONNECTION BETWEEN HAND PUMP AND SLEEVE......116
STOP VALVE......118
GROUND DRIVEN STEERING PUMP (option)......119
DIVERTER VALVE (option)......120
OPERATION......121
FAILURE IN PUMP OR ENGINE WHEN MACHINE IS TRAVELING......122
BRAKE PIPING......124
BRAKE CIRCUIT DIAGRAM......125
BRAKE VALVE......126
BRAKE VALVE (RIGHT)......126
BRAKE VALVE (LEFT)......127
OPERATION......128
ACCUMULATOR CHARGE VALVE......131
ACCUMULATOR (for brake)......135
SLACK ADJUSTER......136
BRAKE......139
PARKING BRAKE CONTROL......141
PARKING BRAKE......142
PARKING BRAKE SOLENOID VALVE......143
PARKING BRAKE VALVE......144
PARKING BRAKE EMERGENCY RELEASE SOLENOID VALVE......145
WORK EQUIPMENT HYDRAULIC SYSTEM DIAGRAM......146
HYDRAULIC PIPING......148
WORK EQUIPMENT HYDRAULIC CIRCUIT DIAGRAM......151
WORK EQUIPMENT LEVER LINKAGE......152
HYDRAULIC TANK......153
BREATHER......154
PPC VALVE......155
OPERATION OF PPC VALVE......157
FUNCTION OF PPC VALVE......158
PPC RELIEF VALVE......160
ACCUMULATOR (FOR PPC VALVE)......161
MAIN CONTROL VALVE......162
RELIEF VALVE......164
SAFETY VALVE (WITH SUCTION)......165
SUCTION VALVE......166
OPERATION OF CUT-OFF VALVE......167
MAIN CONTROL VALVE OPERATION......169
BOOM AND BUCKET SPOOL HOLD POSITION......169
BOOM SPOOL AT RAISE POSITION......170
BOOM SPOOL AT LOWER POSITION......171
BOOM SPOOL AT FLOAT POSITION......172
BUCKET SPOOL AT DUMP POSITION......173
BUCKET SPOOL AT TILT POSITION......174
WORK EQUIPMENT LINKAGE......175
BUCKET......177
BUCKET POSITIONER AND BOOM KICK-OUT......178
ROPS CAB......184
AIR CONDITIONER......185
AIR CONDITIONER PIPING......185
ELECTRIC CIRCUIT DIAGRAM......186
ELECTRIC CIRCUIT DIAGRAM ECSS......187
MACHINE MONITOR SYSTEM......188
OUTLINE......188
MAIN MONITOR......189
MAIN MONITOR DISPLAY FUNCTION......190
MAIN MONITOR SWITCH FUNCTION......191
TROUBLE DATA DISPLAY MODE......192
MAINTENANCE MONITOR......193
MAINTENANCE MONITOR DISPLAY FUNCTION......194
TRANSMISSION AUTO-SHIFT CONTROL SYSTEM......195
SYSTEM STRUCTURE DIAGRAM......195
SHIFT CONTROL SYSTEM FUNCTION......196
GEAR SHIFT CHARACTERISTICS......198
SAFETY FUNCTION......199
TRANSMISSION CONTROLLER......200
ECSS (ELECTRONICALLY CONTROLLED SUSPENSION SYSTEM)......201
CONNECTOR SIGNALS......204
SENSORS......205
ENGINE OIL LEVEL SENSOR......205
RADIATOR WATER LEVEL SENSORS......206
ENGINE WATER TEMPERATURE SENSOR TORQUE CONVERTER OIL TEMPERATURE SENSOR......206
FUEL LEVEL SENSOR......207
ENGINE SPEED SENSOR......208
ENGINE OIL PRESSURE SENSOR......208
ENGINE STARTING CIRCUIT......209
ENGINE STOP CIRCUIT......210
ETHER START CIRCUIT......211
ELECTRIC TRANSMISSION CONTROL......212
COMBINATION SWITCH......213
KICK-DOWN, HOLD SWITCH......215
KICK-DOWN ELECTRIC CIRCUIT DIAGRAM......216
NORMAL OPERATION......216
KICK-DOWN SWITCH OPERATED......217
CANCELING ACTUATION OF KICK-DOWN SWITCH (CASE I)......218
CANCELING ACTUATION OF KICK-DOWN SWITCH (CASE II)......219
TRANSMISSION CUT-OFF SWITCH......220
TRANSMISSION CUT-OFF FUNCTION......221
ELECTRIC PARKING BRAKE CONTROL......223
PARKING BRAKE EMERGENCY RELEASE SWITCH......225
EMERGENCY BRAKE SWITCH......225
PARKING BRAKE SAFETY RELAY......226
NEUTRALIZER RELAY......226
FUNCTION OF PARKING BRAKE NEUTRALIZER RELAY......234
20 TESTING, ADJUSTING, AND TROUBLESHOOTING......235
STANDARD VALUE TABLE FOR CHASSIS......237
SERVICE TOOLS FOR TESTING, ADJUSTING AND TROUBLESHOOTING......244
MEASURING ENGINE SPEEDS......246
MEASURING INTAKE MANIFOLD PRESSURE......246
MEASURING INTAKE AIR RESTRICTION......246
MEASURING ENGINE LUBRICATING OIL PRESSURE......247
MEASURING FUEL INLET RESTRICTION......247
MEASURING BLOW-BY PRESSURE......247
MEASURING EXHAUST BACK PRESSURE......247
MEASURING COOLANT TEMPERATURE......248
MEASURING AND ADJUSTING VALVE CLEARANCE......248
MEASURING WASTEGATE ACTUATOR CALIBRATION......248
MEASURING EXHAUST COLOR......249
MEASURING ACCELERATOR PEDAL......250
OPERATING ANGLE OF ACCELERATOR PEDAL......251
MEASURING OPERATING FORCE, TRAVEL OF SPEED LEVER......252
MEASURING STALL SPEEDS......253
MEASURING TORQUE CONVERTER, TRANSMISSION, PARKING BRAKE OIL PRESSURE......255
METHOD OF OPERATING EMERGENCY MANUAL SPOOL......256
MEASURING CLEARANCE BETWEEN TIRE AND WHEEL......257
TESTING AND ADJUSTING STEERING WHEEL......258
TESTING AND ADJUSTING STEERING CONTROL......260
MEASURING STEERING OIL PRESSURE......261
METHOD OF MEASURING MAIN RELIEF PRESSURE......261
MEASURING OPERATING FORCE, TRAVEL OF BRAKE PEDAL......262
MEASURING BRAKE PERFORMANCE......263
TESTING BRAKE OIL PRESSURE......264
MEASURING BRAKE DISC WEAR......265
BLEEDING AIR FROM BRAKE SYSTEM......266
MEASURING PARKING BRAKE PERFORMANCE......267
MANUAL RELEASE OF PARKING BRAKE......268
MEASURING PARKING BRAKE DISC WEAR......269
MEASURING WORK EQUIPMENT CONTROL LEVER......270
MEASURING WORK EQUIPMENT HYDRAULIC PRESSURE......272
MEASURING WORK EQUIPMENT......276
MEASURING HYDRAULIC DRIFT WORK EQUIPMENT......277
TESTING AND ADJUSTING BUCKET POSITIONER......278
TESTING AND ADJUSTING BOOM KICKOUT......279
ADJUSTING MAIN MONITOR (SPEEDOMETER MODULE)......281
CHECKING FOR ABNORMALITY IN FUEL LEVEL SENSOR......282
TROUBLESHOOTING......284
POINTS TO REMEMBER WHEN TROUBLESHOOTING......285
SEQUENCE OF EVENTS IN TROUBLESHOOTING......286
PRECAUTIONS WHEN CARRYING OUT MAINTENANCE......287
POINTS TO REMEMBER WHEN HANDLING HYDRAULIC EQUIPMENT......292
HANDLING CONNECTORS......294
CHECKS BEFORE TROUBLESHOOTING......295
METHOD OF USING TROUBLESHOOTING CHARTS......297
CONNECTOR TYPES AND MOUNTING LOCATIONS......305
CONNECTOR AND PIN IDENTIFICATION......311
TROUBLESHOOTING OF ENGINE SYSTEM (S-MODE)......318
S-1 STARTING PERFORMANCE IS POOR......319
S-2 ENGINE DOES NOT START......320
S-3 ENGINE DOES NOT ACCELERATE SMOOTHLY (POOR THROTTLE RESPONSE)......323
S-4 ENGINE STOPS DURING OPERATIONS......324
S-5 ENGINE DOES NOT ROTATE SMOOTHLY (HUNTING)......325
S-6 ENGINE LACKS OUTPUT (NO POWER)......326
S-7 EXHAUST IS BLACK (INCOMPLETE COMBUSTION)......327
S-8 OIL CONSUMPTION IS EXCESSIVE (OR EXHAUST GAS IS BLUE)......328
S-9 OIL BECOMES CONTAMINATED QUICKLY......329
S-10 FUEL CONSUMPTION IS EXCESSIVE......330
S-11 OIL IS IN COOLING WATER, OR WATER SPURTS BACK, OR WATER LEVEL GOES DOWN......331
S-12 OIL PRESSURE LAMP LIGHTS UP (DROP IN OIL PRESSURE)......332
S-13 OIL LEVEL RISES......333
S-14 WATER TEMPERATURE BECOMES TOO HIGH......334
S-15 ABNORMAL NOISE IS MADE......335
S-16 VIBRATION IS EXCESSIVE......336
TROUBLESHOOTING OF MAIN MONITOR SYSTEM (M-MODE)......338
TROUBLE DATA DISPLAY......340
M-1 MAIN MONITOR DOES NOT WORK......342
M-2 WHEN STARTING SWITCH IS TURNED ON AND ENGINE IS STARTED IMMEDIATELY, ALL LAMPS STAY LIT......343
M-3 SPEEDOMETER DISPLAYS DOES NOT WORK PROPERLY......344
M-4 ABNORMALITY IN SHIFT INDICATOR......345
A) STAYS AT N EVEN WHEN DIRECTIONAL LEVER IS AT F......345
B) STAYS AT N EVEN WHEN DIRECTIONAL LEVER IS AT R......345
C) DOES NOT DISPLAY N EVEN WHEN DIRECTIONAL LEVER IS AT N AND DISPLAYS R WHEN DIRECTIONAL LEVER IS AT F......345
D) DOES NOT DISPLAY N EVEN WHEN DIRECTIONAL LEVER IS AT N AND DISPLAYS F WHEN DIRECTIONAL LEVER IS AT R......346
E) DOES NOT DISPLAY 1ST, 4TH......346
F) DOES NOT DISPLAY 3RD, 4TH......347
G) DOES NOT DISPLAY 2ND, 3RD......347
H) DOES NOT DISPLAY 1ST, 2ND......348
M-5 HIGH BEAM DOES NOT LIGHT UP......349
M-6 TURN SIGNAL DISPLAY DOES NOT LIGHT UP......350
A) L. H. TURN SIGNAL DOES NOT LIGHT UP......350
B) R. H. TURN SIGNAL DOES NOT LIGHT UP......350
M-7 ABNORMALITY IN PARKING DISPLAY......351
A) PARKING LAMP DOES NOT LIGHT UP......351
B) PARKING LAMP STAYS LIT......351
M-8 NOT USED......351
M-9 NIGHT LIGHTING DOES NOT LIGHT UP......352
M-10 ABNORMALITY IN FRONT WORKING LAMP......353
A) NEITHER MONITOR DISPLAY NOR FRONT WORKING LAMP LIGHT......353
B) WORKING LAMP LIGHTS UP BUT MONITOR DISPLAY DOES NOT LIGHT UP......353
C) MONITOR LIGHTS UP BUT WORKING LAMP DOES NOT LIGHT UP......353
M-11 ABNORMALITY IN REAR WORKING LAMP......354
A) NEITHER MONITOR DISPLAY NOR FRONT WORKING LAMP LIGHT......354
B) WORKING LAMP LIGHTS UP BUT MONITOR DISPLAY DOES NOT LIGHT UP......354
C) MONITOR LIGHTS UP BUT WORKING LAMP DOES NOT LIGHT UP......354
M-12 ABNORMALITY IN TRANSMISSION CUT-OFF......356
A) WHEN MONITOR SWITCH IS PRESSED, CUT-OFF FUNCTION IS NOT SWITCHED AND DISPLAY IS NOT GIVEN......356
B) MONITOR DISPLAY GOES OUT BUT CUT-OFF FUNCTION STAYS ON......356
C) MONITOR DISPLAY LIGHTS UP BUT CUT-OFF FUNCTION IS NOT ACTUATED......357
M-13 ABNORMALITY IN PARKING BRAKE DRAGGING WARNING......358
A) WHEN PARKING BRAKE IS APPLIED, BUZZER SOUNDS (INTERMITTENTLY) EVEN WHEN DIRECTIONAL LEVER IS AT N, AND CAUTION LAMP FLASHE......358
B) WHEN PARKING BRAKE IS APPLIED, BUZZER DOES NOT SOUND AND CAUTION LAMP DOES NOT LIGHT UP EVEN WHEN DIRECTIONAL LEVER IS AT ......358
M-14 WHEN PARKING BRAKE DRAGGING WARNING IS GIVEN, BUZZER AND CAUTION LAMP ARE ACTUATED CONTINUOUSLY, OR THEY ARE NOT ACTUATE......359
A) ACTUATED CONTINUOUSLY......359
B) NOT ACTUATED......359
M-15 ABNORMALITY IN BUZZER......360
A) BUZZER DOES NOT SOUND WHEN STARTING SWITCH IS TURNED ON (DURING SELF CHECK)......360
B) BUZZER ALWAYS SOUNDS......360
M-16 CONDITION OF MONITOR SWITCHES IS NOT STORED IN MEMORY......361
M-17 ABNORMALITY IN FAILURE DISPLAY MODE......362
A) DOES NOT ENTER FAILURE DISPLAY MODE......362
B) TIME DOES NOT ADVANCE FOR "TIME ELAPSED SINCE FAILURE" ON FAILURE DISPLAY MODE......362
M-18 ABNORMALITY IN EMERGENCY STEERING NORMAL DISPLAY......363
A) EMERGENCY STEERING NORMAL DISPLAY DOES NOT LIGHT UP......363
B) EMERGENCY STEERING NORMAL DISPLAY STAYS LIT......363
M-19 ABNORMALITY IN EMERGENCY STEERING ACTUATION DISPLAY......364
A) EMERGENCY STEERING ACTUATION DISPLAY DOES NOT LIGHT UP......364