Komatsu WA420-3 Manual

CEAM003701
Operation&Maintenance
Manual
-3
WHEEL LOADER
SERIAL NUMBERS WA420-3MC A31001 and up
ENGINE 6D114E-1
This material is proprietary to Komatsu America International Company and is not to be reproduced, used, or
disclosed except in accordance with written authorization from Komatsu America International Company.
It is our policy to improve our products whenever it is possible and practical to do so. We reserve the right to make
changes or improvements at any time without incurring any obligation to install such changes on products sold
previously.
Due to this continuous program of research and development, revisions may be made to this publication. It is
recommended that customers contact their distributor for information on the latest revision.
Copyright 2016 Komatsu
Printed in U.S.A
April 2016 Komatsu America Corp.

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WA420-3MC0-0
INTRODUCTION
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TABLE OF CONTENTS
WA420-3MC 0-1
1. FOREWORD
This manual describes procedures for operation, handling, lubrication, maintenance, checking, and adjustment. It will
help the operator and maintenance personnel realize peak performance through effective, economical and safe
machine operation and maintenance.
Keep this manual handy andhave all personnel read it periodically. If this manual is lost or becomes dirty and can not
be read, request a replacement manual from your local distributor.
If you sell the machine, be sure to give this manual to the new owner.
Continuing improvements in the design of this machine can lead to changes in detail, which may not be reflected in this
manual. Consult your local distributor or Komatsu America International Company for the latest available information
on your machine or for questions regarding information in this manual.
WARNING
Improper operation and maintenance of this machine can be hazardous and could result in serious
injury or death.
Operators and maintenance personnel must read this manual thoroughly before operating or
maintaining this machine.
This manual should be kept near the machine for reference and periodically reviewed by all personnel
who come across it.
Some actions involved in operation and maintenance can cause a serious accident, if they are not
performed in the manner described in this manual.
The procedures and precautions given in this manual apply only to intended uses of the machine. If
you use your machine for any unintended uses that are not specifically prohibited, you must be sure
that it is safe for you and others. In no event should you or others engage in prohibited uses or actions
as described in this manual.
Komatsu America International Company delivers machines that comply with all applicable regulations
and standards of the country to which it has been shipped. If this machine has been purchased in
another country or purchased from someone in another country, it may lack certain safety features and
specifications that are necessary for use in your country. If there is any question about whether your
product complies with the applicable standards and regulations of your country, consult your local
distributor or Komatsu America International Company before operating the machine.
See safety rules in SAFETY INFORMATION on page 0-2 and in SAFETY starting page 1-1.
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TABLE OF CONTENTS
WA420-3MC0-2
2. SAFETY INFORMATION
Most accidents are caused by the failure to follow fundamental safety rules for the operation and maintenance of
machines. To avoid accidents, read, understand and follow all precautions and warnings in this manual and on the
machine before performing maintenance and machine operations.
To identify safety messages in thismanual and on machine product graphics, the following signal words are used.
DANGER! - This word is used on safety messages and product graphics where there is a high
probability of serious injury or death if the hazard is not avoided. These safety
messages and product graphics usually describe precautions that must be taken
to avoid the hazard. Failure to avoid this hazard may also result in serious damage
to the machine.
WARNING! - This word is used on safety messages and product graphics where there is a
potentially dangerous situation, which could result in serious injury or death if the
hazard is not avoided. These safety messages and product graphics usually
describe precautions that must be taken to avoid the hazard. Failure to avoid this
hazard may also result in serious damage to the machine.
CAUTION! - This word is used on safety messages and product graphics for hazards, which
could result in minor or moderate injury if the hazard is not avoided. These safety
messages and product graphics might also use this word for hazards where the
only result could be damage to the machine.
NOTE - This word is used for precautions that must be taken to avoid actions, which could
shorten the life of the machine.
Safety precautions are described in SAFETY beginning on page 1-1.
Komatsu America International Company cannot predict every circumstance that mightinvolve a potential hazard in
operationand maintenance. Therefore the safety message in this manual and on the machine may not include all
possiblesafety precautions. If any procedures or actions not specifically recommended or allowed in this manual are
used, you must be sure that you and others can do such procedures and actions safely and without damaging the
machine. If you are unsure about the safety of some procedures, contact your local distributor or Komatsu America
International Company.
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TABLE OF CONTENTS
WA420-3MC 0-3
3. INTRODUCTION
3.1 INTENDED USE
This WHEEL LOADER is designed to be used mainly for the following work:
Digging
Leveling
Pushing
Loading
For details of the operating procedures, SEE "12.10 WORK POSSIBLE USING WHEEL LOADER" on page 2-58
3.2 FEATURES
Curved glass and improved sealing for reduced noise, low vibration cab, viscous mount.
Console and steering post with unencumbered foot area providing the same comfort level as an automobile.
Fully hydraulic brake system, which does not require draining water or concerns of rust and freezing.
Maintenance-free, wet-type disc parking brake (acts also as emergency brake).
Large capacity pump and 2-stage hydraulic system for reduced cycle time and increased productivity.
One-touch panel control and optional air conditioner with new refrigerant.
Full fender system available to help prevent mud or water from splashing on or around the machine.
3.3 BREAKING IN A NEW MACHINE
Your machine has been thoroughly adjusted and tested before shipment. However, operating the machine under
severe conditions at the beginning can adversely affect the performance and shorten the machine life.
Be sure to break in the machine for the initial 100 hours (as indicated by the service meter).
During break in:
After starting, let the engine idle for five minutes to allow proper engine warm-up prior to actual operation.
Avoid operation with heavy loads or at high speeds.
Avoid sudden starts or acceleration, unnecessarily abrupt stops and sharp steering except in cases of
emergency.
The precautions given in this manual for operating, maintenance, and safety procedures are only those that apply
when this product is used for the specified purpose. If the machine is used for a purpose that is not listed in this
manual, Komatsu America International Company cannot bear any responsibility for safety. All consideration of
safety in such operations is the responsibility of the user.
Operations that are prohibited in this manual must never be carried out under any circumstance.
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TABLE OF CONTENTS
WA420-3MC0-4
4. LOCATION OF PLATES, TABLE FOR SERIAL NUMBER AND
DISTRIBUTOR
4.1 MACHINE SERIAL NO. PLATE POSITION
(A) Position of plate
On the center right of the front frame.
(B) Position of stamp
This is stamped on the centerof the front frame on the right
hand side of the machine.
4.2 ENGINE SERIAL NO. PLATE POSITION
Position of plate
On the upper right of the cylinder block, when seen from the
fan side.
4.3 TABLE TO ENTER SERIAL NO. AND DISTRIBUTOR
Machine serial No.:
Engine serial No.:
Distributor name:
Address: Phone:
Service personnel for your machine:
REMARKS
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TABLE OF CONTENTS
WA420-3MC 0-5
5. TABLE OF CONTENTS
1. FOREWORD ............................................................................0-2
2. SAFETY INFORMATION ...................................................................0-3
3. INTRODUCTION .........................................................................0-4
3.1 INTENDED USE ...................................................................0-4
3.2 FEATURES .......................................................................0-4
3.3 BREAKING IN A NEW MACHINE .....................................................0-4
4. LOCATION OF PLATES, TABLE FOR SERIAL NUMBER AND DISTRIBUTOR .......................0-5
4.1 MACHINE SERIAL NO. PLATE POSITION ..............................................0-5
4.2 ENGINE SERIAL NO. PLATE POSITION ...............................................0-5
4.3 TABLE TO ENTER SERIAL NO. AND DISTRIBUTOR ....................................0-5
6. GENERAL PRECAUTIONS .................................................................1-2
7. PRECAUTIONS DURING OPERATION .......................................................1-8
7.1 BEFORE STARTING ENGINE ........................................................1-8
7.2 OPERATING MACHINE .............................................................1-9
7.3 TRANSPORTATION ...............................................................1-18
7.4 BATTERY .......................................................................1-19
7.5 TOWING ........................................................................1-21
8. PRECAUTIONS FOR MAINTENANCE .......................................................1-22
8.1 BEFORE CARRYING OUT MAINTENANCE ...........................................1-22
8.2 DURING MAINTENANCE ..........................................................1-27
8.3 TIRES ..........................................................................1-31
9. SAFETY LABELS ........................................................................1-33
10. GENERAL VIEW .........................................................................2-2
10.1 GENERAL VIEW OF MACHINE.......................................................2-2
10.2 GENERAL VIEW OF CONTROLS AND GAUGES ........................................2-3
11. EXPLANATION OF COMPONENTS ..........................................................2-4
11.1 MACHINE MONITORS ..............................................................2-4
11.1.1 WARNING DISPLAYS ...........................................................2-6
11.1.2 METER DISPLAY PORTION .....................................................2-10
11.2 SWITCHES ......................................................................2-14
11.3 CONTROL LEVERS, PEDALS ......................................................2-21
11.4 STEERING COLUMN TILT LEVER ...................................................2-26
11.5 CAP WITH LOCK .................................................................2-27
11.5.1 METHOD OF OPENING AND CLOSING CAP WITH LOCK............................2-27
11.6 SAFETY BAR ....................................................................2-29
11.7 TOWING PIN.....................................................................2-29
11.8 GREASE PUMP ..................................................................2-30
11.9 BACK UP ALARM .................................................................2-30
11.10 FUSE ...........................................................................2-31
11.10.1 FUSE CAPACITY AND NAME OF CIRCUIT ........................................2-31
11.11 SLOW-BLOW FUSE ...............................................................2-32
11.12 STORAGE FOR THIS MANUAL .....................................................2-33
11.13 ELECTRIC POWER (with ROPS CAB.................................................2-33
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TABLE OF CONTENTS
WA420-3MC0-6
12. OPERATION ............................................................................2-34
12.1 CHECKS BEFORE STARTING ......................................................2-34
12.1.1 WALK AROUND CHECK .......................................................2-34
12.1.2 CHECK BEFORE STARTING ....................................................2-37
12.1.3 ADJUSTMENT BEFORE OPERATION ............................................2-42
12.1.4 OPERATIONS AND CHECKS BEFORE STARTING ENGINE ..........................2-45
12.2 STARTING ENGINE ...............................................................2-47
12.2.1 COLD WEATHER STARTING ...................................................2-48
12.3 OPERATIONS AND CHECKS AFTER STARTING ENGINE ...............................2-49
12.4 MOVING MACHINE ...............................................................2-50
12.5 CHANGING GEARS ..............................................................2-52
12.6 CHANGING DIRECTION ...........................................................2-52
12.7 TURNING .......................................................................2-53
12.8 STOPPING MACHINE .............................................................2-54
12.9 OPERATION OF WORK EQUIPMENT ................................................2-55
12.9.1 STANDARD WORK EQUIPMENT CONTROLS .....................................2-55
12.9.2 MONO-LEVER WORK EQUIPMENT CONTROLS ...................................2-57
12.10 WORK POSSIBLE USING WHEEL LOADER...........................................2-58
12.10.1 DIGGING OPERATIONS ........................................................2-58
12.10.2 LEVELING OPERATIONS .......................................................2-61
12.10.3 PUSHING OPERATION ........................................................2-61
12.10.4 LOAD AND CARRY OPERATIONS ...............................................2-61
12.10.5 LOADING OPERATIONS .......................................................2-62
12.11 PRECAUTIONS FOR OPERATION ..................................................2-63
12.11.1 PERMISSIBLE WATER DEPTH ..................................................2-63
12.11.2 IF WHEEL BRAKE DOES NOT WORK ............................................2-63
12.11.3 PRECAUTIONS WHEN DRIVING UP OR DOWN SLOPES ............................2-63
12.11.4 PRECAUTIONS WHEN DRIVING MACHINE .......................................2-64
12.12 ADJUSTING WORK EQUIPMENT POSTURE ..........................................2-65
12.12.1 ADJUSTING BOOM KICKOUT ...................................................2-65
12.12.2 ADJUSTING BUCKET POSITIONER ..............................................2-66
12.12.3 BUCKET LEVEL INDICATOR ....................................................2-66
12.13 PARKING MACHINE ..............................................................2-67
12.14 CHECKS AFTER COMPLETION OF OPERATION ......................................2-68
12.15 STOPPING ENGINE ...............................................................2-68
12.16 CHECK AFTER STOPPING ENGINE .................................................2-69
12.17 LOCKING .......................................................................2-69
12.18 HANDLING THE TIRES ............................................................2-70
12.18.1 PRECAUTIONS WHEN HANDLING TIRES .........................................2-70
12.18.2 TIRE PRESSURE .............................................................2-70
13. TRANSPORTATION .....................................................................2-72
13.1 LOADING AND UNLOADING .......................................................2-72
13.2 PRECAUTIONS FOR LOADING .....................................................2-73
13.3 PRECAUTIONS FOR TRANSPORTATION ............................................2-73
13.4 LIFTING MACHINE ................................................................2-73
13.4.1 LOCATION FOR LIFTING POSITION DECALS......................................2-74
13.4.2 WEIGHT TABLE ..............................................................2-74
13.4.3 LIFTING PROCEDURE .........................................................2-75
14. COLD WEATHER OPERATION ............................................................2-76
14.1 PRECAUTIONS FOR LOW TEMPERATURE ..........................................2-76
14.1.1 FUEL AND LUBRICANTS .......................................................2-76
14.1.2 COOLANT ...................................................................2-76
14.1.3 BATTERY ....................................................................2-76
14.2 PRECAUTIONS AFTER COMPLETION OF WORK ..................................2-77
14.3 AFTER COLD WEATHER .......................................................2-77
15. LONG TERM STORAGE ..................................................................2-78
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TABLE OF CONTENTS
WA420-3MC 0-7
15.1 BEFORE STORAGE ...............................................................2-78
15.2 DURING STORAGE ...............................................................2-78
15.3 AFTER STORAGE ................................................................2-78
16. TROUBLESHOOTING ....................................................................2-79
16.1 WHEN MACHINE RUNS OUT OF FUEL ..............................................2-79
16.2 TOWING THE MACHINE ...........................................................2-80
16.2.1 WITH THE ENGINE RUNNING ..................................................2-81
16.2.2 WITH THE ENGINE STOPPED ..................................................2-81
16.2.3 RELEASING PARKING BRAKE ..................................................2-82
16.2.4 EMERGENCY TRAVEL OPERATION .............................................2-83
16.3 IF BATTERY IS DISCHARGED ......................................................2-84
16.3.1 REMOVAL AND INSTALLATION OF BATTERY .....................................2-84
16.3.2 PRECAUTION FOR CHARGING BATTERY ........................................2-85
16.3.3 STARTING ENGINE WITH BOOSTER CABLE ......................................2-86
16.4 OTHER TROUBLE ................................................................2-88
16.4.1 ELECTRICAL SYSTEM .........................................................2-88
16.4.2 CHASSIS ....................................................................2-89
16.4.3 ENGINE .....................................................................2-92
17. GUIDES TO MAINTENANCE ...............................................................3-2
18. OUTLINES OF SERVICE ...................................................................3-5
18.1 OUTLINE OF OIL, FUEL, COOLANTS .................................................3-5
18.1.1 OIL ..........................................................................3-5
18.1.2 FUEL .........................................................................3-6
18.1.3 COOLANT ....................................................................3-6
18.1.4 GREASE ......................................................................3-6
18.1.5 STORING OIL AND FUEL ........................................................3-7
18.1.6 FILTERS ......................................................................3-7
18.1.7 FUEL INJECTION PUMP ........................................................3-7
18.2 OUTLINE OF ELECTRIC SYSTEM ....................................................3-8
19. WEAR PARTS LIST .......................................................................3-9
20. FUEL, COOLANT AND LUBRICANTS ACCORDING TO AMBIENT TEMPERATURE .................3-10
20.1 PROPER SELECTION OF FUEL, COOLANT AND LUBRICANTS ..........................3-10
20.2 ENGINE OIL SPECIFICATIONS .....................................................3-11
20.2.1 NORMAL OPERATION .........................................................3-11
20.2.2 ARCTIC OPERATION ..........................................................3-11
20.3 TRANSMISSION, TORQUE CONVERTER, TRANSFER CASE AND OIL COOLER,
SERVICE BRAKES AND HYDRAULIC SYSTEM OIL SPECIFICATIONS .................3-12
20.4 FINAL DRIVE OIL SPECIFICATIONS .................................................3-12
20.5 DRIVE AXLE OIL SPECIFICATIONS..................................................3-12
20.6 DIESEL FUEL SPECIFICATIONS ....................................................3-12
20.7 COOLANT SPECIFICATIONS .......................................................3-13
20.7.1 GENERAL ...................................................................3-13
20.7.2 WATER ......................................................................3-13
20.7.3 ANTIFREEZE .................................................................3-13
20.7.4 SUPPLEMENTAL COOLANT ADDITIVES ..........................................3-14
21. STANDARD TIGHTENING TORQUE FOR NUTS AND BOLTS ...................................3-19
21.1 INTRODUCTION OF NECESSARY TOOLS ............................................3-19
21.2 TORQUE LIST ...................................................................3-20
22. PERIODIC REPLACEMENT OF SAFETY CRITICAL PARTS .....................................3-21
23. MAINTENANCE SCHEDULE ..............................................................3-25
23.1 SCHEDULED MAINTENANCE CHART ...............................................3-25

TABLE OF CONTENTS
WA420-3MC0-8
24. SERVICE PROCEDURE ..................................................................3-29
24.1 INITIAL 250 HOURS SERVICE ......................................................3-29
24.2 WHEN REQUIRED ................................................................3-30
24.2.1 CLEAN OR REPLACE AIR CLEANER ELEMENT ....................................3-30
24.2.2 CHECK TRANSMISSION OIL LEVEL, ADD OIL .....................................3-32
24.2.3 CHECK AXLE OIL LEVEL, ADD OIL ..............................................3-33
24.2.4 CLEAN THE AXLE CASE BREATHER ............................................3-34
24.2.5 CLEAN THE RADIATOR FINS ...................................................3-34
24.2.6 REPLACE THE BOLT-ON CUTTING EDGES .......................................3-35
24.2.7 REPLACE BUCKET TEETH .....................................................3-35
24.2.8 CHECK AIR CONDITIONER .....................................................3-37
24.2.9 CLEAN THE AIR CONDITIONER CONDENSER ....................................3-38
24.2.10 OPERATE THE AIR CONDITIONER OFF SEASON ..................................3-38
24.2.11 CHECK WINDOW WASHING FLUID, ADD FLUID ...................................3-38
24.2.12 LUBRICATE WORK EQUIPMENT CONTROL VALVE LINKAGE (2 PLACES) .............3-38
24.2.13 REPLACE SLOW BLOW FUSE ..................................................3-39
24.3 SELECTION AND INSPECTION OF TIRES ............................................3-40
24.4 CHECKS BEFORE STARTING ......................................................3-41
24.4.1 CHECK MONITOR PANEL ......................................................3-41
24.4.2 CHECK COOLANT LEVEL, ADD WATER ..........................................3-41
24.4.3 CHECK FUEL LEVEL, ADD FUEL ................................................3-41
24.4.4 CHECK OIL LEVEL IN ENGINE OIL PAN, ADD OIL ..................................3-42
24.4.5 CHECK ELECTRIC WIRING .....................................................3-43
24.4.6 DRAIN WATER FROM FUEL WATER SEPARATOR .................................3-43
24.4.7 CHECK EFFECT OF PARKING BRAKE ...........................................3-44
24.4.8 CHECK EFFECT OF BRAKE ....................................................3-44
24.4.9 CHECK SOUND OF HORN AND BACKUP ALARM ..................................3-44
24.4.10 CHECK FLASHING OF LAMPS, CHECK FOR DIRT OR DAMAGE......................3-44
24.4.11 CHECK ENGINE EXHAUST COLOR AND SOUND ..................................3-44
24.4.12 CHECK OPERATION OF GAUGES ...............................................3-44
24.4.13 CHECK PLAY OF STEERING WHEEL, CHECK OPERATION OF STEERING ............3-44
24.4.14 CHECK DIRECTION OF REAR VIEW MIRROR, CHECK FOR DIRT OR DAMAGE ........3-44
24.5 EVERY 50 HOURS SERVICE .......................................................3-45
24.5.1 DRAIN WATER, SEDIMENT FROM FUEL TANK ....................................3-45
24.6 EVERY 100 HOURS SERVICE ......................................................3-45
24.6.1 CHECK OIL LEVEL IN HYDRAULIC TANK, ADD OIL.................................3-45
24.6.2 CLEAN ELEMENT IN AIR CONDITIONER FRESH AIR FILTER ........................3-46
24.6.3 LUBRICATE REAR AXLE PIVOT PIN (3 PLACES) ...................................3-46
24.7 EVERY 250 HOURS SERVICE ......................................................3-47
24.7.1 CHANGE OIL IN ENGINE OIL PAN, REPLACE ENGINE OIL FILTER CARTRIDGE ........3-47
24.7.2 CHECK FOR LOOSE WHEEL HUB BOLTS, TIGHTEN ...............................3-48
24.7.3 CLEAN ELEMENT IN AIR CONDITIONER RECIRCULATION FILTER ...................3-48
24.7.4 CHECK AIR CONDITIONER COMPRESSOR BELT TENSION, ADJUST .................3-49
24.7.5 CHECK BATTERY ELECTROLYTE LEVEL ........................................3-50
24.7.6 LUBRICATING ................................................................3-51
24.8 EVERY 500 HOURS SERVICE ......................................................3-52
24.8.1 REPLACE FUEL FILTER CARTRIDGE ............................................3-52
24.8.2 REPLACE TRANSMISSION OIL FILTER ELEMENT..................................3-54
24.8.3 CORROSION RESISTOR .......................................................3-55
24.9 EVERY 1000 HOURS SERVICE .....................................................3-56
24.9.1 CHANGE OIL IN TRANSMISSION, CLEAN STRAINER ...............................3-56
24.9.2 CLEAN TRANSMISSION CASE BREATHER .......................................3-57
24.9.3 LUBRICATE ..................................................................3-57
24.9.4 CHECK ENGINE VALVE CLEARANCE, ADJUST ....................................3-59
24.9.5 CHECK TENSION OF DRIVE BELT ...............................................3-62
24.9.6 CHECK DRIVE BELT TENSIONER BEARING AND FAN HUB BEARING ................3-62
24.10 EVERY 2000 HOURS SERVICE .....................................................3-64
24.10.1 COOLING SYSTEM, REPLACE COOLANT AND FLUSH THE SYSTEM .................3-64
24.10.2 CHANGE OIL IN HYDRAULIC TANK, REPLACE HYDRAULIC FILTER ELEMENT .........3-68

TABLE OF CONTENTS
WA420-3MC 0-9
24.10.3 REPLACE HYDRAULIC TANK BREATHER ELEMENT ...............................3-71
24.10.4 CHANGE AXLE OIL ............................................................3-71
24.10.5 CHECK BRAKE DISC WEAR ....................................................3-71
24.10.6 CHECK VIBRATION DAMPER ...................................................3-71
24.10.7 REPLACE ELEMENT IN AIR CONDITIONER RECIRCULATION FILTER
AND FRESH FILTER ...........................................................3-72
24.10.8 CLEAN PPC CIRCUIT STRAINER ................................................3-72
24.10.9 CHECK ACCUMULATOR GAS PRESSURE ........................................3-72
25. DIMENSIONS ............................................................................4-2
25.1 WITH SMALL TIRES ...............................................................4-2
25.2 WITH LARGE TIRES ...............................................................4-3
25.3 SPECIFICATIONS .................................................................4-4
26. OPTIONAL PARTS AND ATTACHMENTS ....................................................5-2
27. SELECTING BUCKETS AND TIRES .........................................................5-3
28. AIR CONDITIONING ......................................................................5-4
28.1 GENERAL LOCATIONS AND FUNCTION OF CONTROL PANEL ...........................5-4
28.1.1 FAN SWITCH ..................................................................5-4
28.1.2 AIR CONDITIONER SWITCH .....................................................5-4
28.1.3 MODE SELECTOR SWITCH .....................................................5-5
28.1.4 FRESH/RECIRC SELECTOR SWITCH .............................................5-5
28.1.5 TEMPERATURE CONTROL SWITCH ..............................................5-5
28.2 METHOD OF OPERATION ..........................................................5-6
28.2.1 WHEN NOT USING THE AIR CONDITIONER REGULARLY ............................5-6
28.3 COOL BOX .......................................................................5-6
29. HANDLING ECSS ........................................................................5-7
29.1 STRUCTURE AND FUNCTION OF ECSS ..............................................5-7
29.2 METHOD OF OPERATING ECSS .....................................................5-8
29.3 PRECAUTIONS WHEN OPERATING ECSS SWITCH ....................................5-8
29.4 ACCUMULATOR PRECAUTIONS ....................................................5-9
29.5 DISCONNECTING THE ECSS PIPING ................................................5-10
30. OPTION DISPLAY .......................................................................5-11
30.1 EMERGENCY STEERING PILOT LAMP...............................................5-11
30.2 RADIO ..........................................................................5-12
30.2.1 OPERATING CONTROLS ......................................................5-12
30.2.2 OPERATION .................................................................5-13
30.2.3 SETTING THE CLOCK .........................................................5-15
30.2.4 REMOTE CONTROL UNIT ......................................................5-15
30.2.5 BATTERY REPLACEMENT .....................................................5-16
30.2.6 PRECAUTIONS WHEN USING ..................................................5-16

WA420-3MC0-10
MEMORANDA

WA420-3MC 1-1
SAFETY
WARNING
Read and follow all safety precautions. Failure to do so may
result in serious injury or death.
This safety section also contains precautions for optional
equipment and attachments.

SAFETY WARNING: Forreasons of safety, always follow
these safety precautions.
1-2 WA420-3MC
6. GENERAL PRECAUTIONS
SAFETY RULES
ONLY trained and authorized personnel should be allowed to operate and service this machine.
Follow all safety rules, precautions and instructions when operating or performing maintenance on the machine.
The owner and/or operator must replace any and all safety and warning product graphics if they are defaced or
removed from the machine.
Think before you act. Careful operators and service personnel are the best insurance against accidents.
Do not rush. Hurrying can lead to accidents. Haste, carelessness and lack of training are the primary causes of
equipment-related injuries.
The operator must be alert, physically fit and free from the influences of alcohol, drugs and medications that
might affect his eyesight, hearing or reactions.
Safety must always be the operator's most important concern. He must refuse to operate when he knows it is
unsafe and consult his supervisor when safety is in doubt.
When working with another operator or a person on work site traffic duty, be sure all personnel understand all
hand signals that are to be used.
SAFETY FEATURES
Be sure all guards and covers are in their proper position. Be sure to replace them after servicing the machine.
Have guards and covers repaired immediately if damaged.
Proper position
Use safety features such as safety lock lever and seat belt properly.
A seat belt is required by OSHA in almost all applications. DO NOT operate this machine without a seat belt.
NEVER remove any safety features. ALWAYS keep them in good operating condition.
Safety lock lever
Seat belts
Improper use of safety features could result in serious bodily injury or death.
Be sure the machine has the correct equipment required by local rules and regulations.
UNAUTHORIZED MODIFICATION
Any modification made without authorization from Komatsu America International Company can create
hazards.
Before making a modification, consult your local distributor. Komatsu America International Company will not
be responsible for any injury or damage caused by any unauthorized modification.

WARNING: Failure to follow these safety
precautions may lead to a serious accident. SAFETY
WA420-3MC 1-3
CLOTHING AND PERSONAL PROTECTIVE ITEMS
Avoid loose clothing, jewelry, and loose long hair. They can catch on controls or in moving parts and cause
serious injury or death. Also, do not wear oily clothes because they are flammable.
Wear a hard hat, safety glasses, safety shoes, mask or gloves when operating or maintaining the machine.
Always wear safety goggles, hard hat and heavy gloves if your job involves scattering metal chips or minute
materials - this is particularly important when driving pins with a hammer and when cleaning the air filter
element with compressed air.
Also check that there are no other personnel near the machine.
Cleaning of air cleaner element
Check that all protective equipment functions properly before using the machine.
ALWAYS APPLY LOCK WHEN LEAVING OPERATOR'S SEAT
When standing up from the operator's seat, always place the safety lock lever securely in the LOCK position. If
you accidentally touch the equipment levers when they are not locked, the machine or work equipment may
move and cause serious injury or damage.
When leaving the machine, lower the work equipment completely to the ground, set the safety lock lever to the
LOCK position, then stop the engine and use the key to lock all the equipment locks. Always take the key with
you.
Work equipment posture
Locks

SAFETY WARNING: Forreasons of safety, always follow
these safety precautions.
1-4 WA420-3MC
MOUNTING AND DISMOUNTING
Climbing on the machine improperly can cause injury. NEVER jump on or off the machine. NEVER get on or off
a moving machine.
When mounting or dismounting, always face the machine and use the handrails and steps.
Do not use the machine's controls or hoses as supports when climbing on or off the machine. Controls and
hoses can move and do not provide solid support. Movement of the controls may cause unexpected machine
movement and injury.
Ensure safety by always maintaining at least three-point contact of hands and feet with the handrails and steps.
Always remove any oil or mud from the handrails and steps. If they are damaged, repair them and tighten any
loose hardware.
FIRE PREVENTION FOR FUEL AND OIL
Fuel, oil, and antifreeze can be ignited by a flame. Fuel is particularly FLAMMABLE and can be HAZARDOUS.
Keep any flame away from flammable fluids.
Stop the engine and do not smoke when refueling.
Tighten all fuel and oil caps securely.
Refueling and lubricating should be done in well ventilated areas.
Keep oil and fuel in the determined place and do not allow unauthorized persons to enter.

WARNING: Failure to follow these safety
precautions may lead to a serious accident. SAFETY
WA420-3MC 1-5
PRECAUTIONS WHEN HANDLING AT HIGH TEMPERATURES
Engine coolant, engine oil, and hydraulic oil can reach high temperatures, and are under pressure during
operation. Attempting to remove the cap, drain the oil or water, or replace the filters may lead to serious burns.
Stop the engine and wait for the temperature and pressure to subside, and follow the specified procedures
when carrying out these operations.
To prevent hot water from spurting out:
1) Turn engine off.
2) Allow water to cool.
3) Slowly loosen cap to relieve pressure before removing.
To prevent hot oil from spurting out:
1) Turn engine off.
2) Allow oil to cool.
3) Slowly loosen cap to relieve pressure before removing.
ASBESTOS DUST HAZARD PREVENTION
Asbestos dust is HAZARDOUS to your health if inhaled.
If you handle materials containing asbestos fibers, follow these guidelines as given below:
NEVER use compressed air for cleaning.
Use water for cleaning to keep down the dust.
Operate the machine with the wind to your back, whenever possible.
Use an approved respirator.
CRUSHING OR CUTTING PREVENTION
Keep hands, arm and all other parts of the body away from movable parts such as between the work
equipment and cylinders, or between the machine and work equipment. If the work equipment is operated, the
clearance will change and this may lead to serious damage or personal injury.

SAFETY WARNING: Forreasons of safety, always follow
these safety precautions.
1-6 WA420-3MC
FIRE EXTINGUISHER AND FIRST AID KIT
Make sure fire extinguishers of the correct type are kept in good condition and convenient to the operators and
other personnel. Make sure the appropriate personnel have been trained in their use.
Provide a first aid kit at the storage point.
Know what to do in the event of a fire.
Be sure you know the phone numbers of persons you should contact in case of an emergency.
PRECAUTIONS WHEN USING ROPS
Never operate the machine without a ROPS (ROLL OVER PROTECTIVE STRUCTURE) properly installed and
in good condition.
The ROPS is installed to protect the operator if the machine should roll over. It is designed not only to support
the load if the machine should roll over, but also to absorb the impact energy.
The ROPS fulfills all the regulations and standards for all countries, but if it is rebuilt without authorization or is
damaged when the machine rolls over, its strength may suffer and it may be unable be able to fulfill its function
properly. It can perform if it is repaired or modified in the specified way.
When modifying or repairing the ROPS, always contact your Komatsu America International Company
distributor.
Even if the ROPS is installed, it cannot show its full effect if the operator does not fasten the seat belt properly.
Always fasten the seat belt when operating.
PRECAUTIONS FOR ATTACHMENTS
When installing and using an optional attachment, read the instruction manual for the attachment and the
information related to attachments in this manual.
Do not use attachments that are not authorized by your distributor or Komatsu America International Company.
Use of unauthorized attachments could create a safety problem and adversely affect the proper operation and
useful life of the machine.
Any injuries, accidents, product failures resulting from the use of unauthorized attachments will not be the
responsibility of Komatsu America International Company.