PDF Shop Manual Komatsu WA70M-8E0 Wheel Loader - 7 MB
This complete shop manual is the definitive guide for servicing and repairing the Komatsu WA70M-8E0 wheel loader.
It contains detailed procedures for testing, adjusting, disassembling, and assembling every component of the machine.
Professional technicians will find the specifications, diagrams, and troubleshooting charts invaluable for any repair.
This is the essential resource for keeping your wheel loader in peak operating condition.
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--- Page 1 ---
Shop Manual VENBM09000
WHEEL LOADER
-8E0
Model: Serial number:
WA70M-8E0 H71051 and up
• This shop manual may contain attachments and optional equipment that are not available in your area.
Please consult your local KOMATSU distributor for those items you may require.
• Materials and specifications are subject to change without notice.
• The Wheel Loader WA70M-8E0 is equipped with the engine 4D98E-6SHA.
• For details of this engine see Engine Manual: WA100M-8 in attachment.
© 2020
All Rights Reserved
Printed in Europe 2020-04
--- Page 3 ---
INDEX AND FOREWORD FOREWORD, SAFETY, BASIC INFORMATION
50 DISASSEMBLY AND ASSEMBLY
This section describes the special tools, work procedures, and
safety precautions necessary for removal, installation, disas-
sembly, and assembly of the components and parts. In addition,
tightening torques, quantity, and weight of the coating materials,
lubricants, and coolant necessary to these works are shown.
60 MAINTENANCE STANDARDS
This section describes the maintenance standard value of each
component. The maintenance standard shows the criteria and
remedies for disassembly and assembly.
80 THE OTHER INFORMATION
This section describes the structure and function, testing and
adjusting, and troubleshooting for all of the other components or
equipment which cannot be separately classified in the appen-
dix.
90 Circuit diagrams
This section describes hydraulic circuit diagrams and electrical
circuit diagrams.
KOMATSU 00-9
--- Page 4 ---
INDEX AND FOREWORD FOREWORD, SAFETY, BASIC INFORMATION
Selecting wire ropes
Select adequate ropes depending on the weight of the parts to
be hoisted referring to the table below.
REMARK
The allowable load is calculated with one sixth (safety factor 6)
of the breaking load of the rope.
Wire rope (JIS G3525 6x37-A type) (Standard Z twist wire
ropes without galvanizing)
Nominal diameter of rope (mm) Allowable load (kN {t})
10 8.8 {0.9}
12 12.7 {1.3}
14 17.3 {1.7}
16 22.6 {2.3}
18 28.6 {2.9}
20 35.3 {3.6}
25 55.3 {5.6}
30 79.6 {8.1}
40 141.6 {14.4}
50 221.6 {22.6}
60 318.3 {32.4}
Precautions for disconnecting air conditioner piping
NOTICE
When replacing the air conditioner unit, air conditioner compres-
sor, condenser or receiver drier, etc., collect the refrigerant (air
conditioner gas: R134a) from the air conditioner circuit before
disconnecting the air conditioner hoses.
REMARK
• Ask a qualified person for collecting, adding and filling oper-
ations of the refrigerant (air conditioner gas: R134a).
• Never release the refrigerant (air conditioner gas: R134a) to
the atmosphere.
k Put on the protective eyeglasses, gloves and working
clothes with long sleeves while you are collecting or
filling the refrigerant. Otherwise, when refrigerant gas
(R134a) gets in your eyes, you may lose your sight, and
when it touches your skin, you may suffer from frost-
bite.
• When loosening the nuts fixing air conditioner hoses and
tubes, be sure to use 2 wrenches; use one wrench to fix and
use the other one to loosen the nut.
Precautions for air conditioner piping
• When installing the air conditioner piping, be careful so that
dirt, dusts and water do not enter the hose.
Check that the O-rings are fitted to the joints when connecting
the air conditioner piping.
KOMATSU 00-19
--- Page 5 ---
INDEX AND FOREWORD PRECAUTIONS FOR DISCONNECTION AND CONNECTION OF PIPINGS
PRECAUTIONS FOR DISCONNECTION AND CONNEC-
TION OF PIPINGS
When performing "testing and adjusting" of the machine, "re-
moval and installation" and "disassembly and assembly" of the
components, observe the following precautions.
PRECAUTIONS FOR REMOVAL AND DISASSEMBLING WORK
• If the cooling water contains coolant, dispose of it correctly
as chemicals. Do not drain it to the sewage rashly.
• After disconnecting the hoses or tubes, plug them to prevent
dust from entering.
• When draining oil, prepare a container with sufficient capac-
ity.
• Check the matchmarks which indicate the installing position
and put matchmarks on the places where they seem neces-
sary before removal of the components to prevent any mis-
take when assembling.
• To prevent any excessive force from being applied to the
wiring, always hold the connectors when disconnecting the
connectors. Do not pull the wires.
• Attach the tags to wires and hoses so that installation is do-
ne to the correct installing positions.
• Check the thickness and number of shims when storing
shims.
• When hoisting the components, prepare the slings with suffi-
cient strength.
• When using forcing screws to remove any component, tight-
en the forcing screws uniformly and alternately.
• Before removing any component, clean the surrounding ar-
ea and cover the component to prevent any foreign material
from entering after removal.
• To disconnect the face seal type hose from the cylinder
tube, loosen the joint by gripping the two wrenches together,
one is the wrench (1) on the hose side, and another is the
wrench (2) on the cylinder tube reaction force point as
shown in the following figure. Use the grip strength only.
Check after disconnecting the hose that the joint portion of
the cylinder and the cylinder tube is tightened to the speci-
fied torque. Re-tighten it if the tightening torque is insuffi-
cient.
NOTICE
Cylinder tube is rotated due to the load applied to the re-
action force point of the cylinder tube, and it is a cause
of weakening of the tightening torque. It may lead to oil
leakage.
KOMATSU 00-29
--- Page 6 ---
INDEX AND FOREWORD PRECAUTIONS FOR DISCONNECTION AND CONNECTION OF PIPINGS
Check of function of muffler in exhaust system
REMARK
When an equipment is described as a muffler in exhaust system,
it is one of the followings. (The applications or components of
equipment are different depending on its models or specifica-
tions.)
• DPF
• DOC muffler
• Muffler
• Exhaust pipe
• Parts which connects the above, or etc.
Check that there is no unusual noise by comparing to it of the
time when the machine was new.
If there is any unusual noise, repair DPF or muffler, referring to
"TROUBLESHOOTING" and "DISASSEMBLY AND ASSEM-
BLY".
KOMATSU 00-39
--- Page 7 ---
INDEX AND FOREWORD PRECAUTIONS FOR HANDLING ELECTRICAL EQUIPMENT
3. Correct the protrusion of the boot and misalignment of the
wiring harness.
• If the connector is with the boot, correct any extrusion of
the boot. In addition, if the wiring harness is misaligned
or the clamp is out of position, adjust it to its correct po-
sition.
REMARK
If the protrusion of the boot and misalignment of the wir-
ing harness cannot be fixed, remove the clamp to adjust
them.
• If the connector clamp is removed, be sure to return it to
its original position. Check that there is no looseness.
KOMATSU 00-49
--- Page 8 ---
INDEX AND FOREWORD PRECAUTIONS FOR HANDLING ELECTRICAL EQUIPMENT
Method for connecting ring terminals and strip fuses to power stud of printed circuit
boards
The assembly of a strip fuse and a wire terminal with a power
stud on a printed circuit board, has to be performed as follows:
g0011033
A direct connection between the stud and the conductive ele-
ment is required and no mounting elements are to come in be-
tween.
For the board equipped with spring washers, it is expressly for-
bidden to reuse these elements if they were tightened with high
torque.
Consider the following maximum torque for the nuts on the pow-
er studs of the printed circuit boards (central electric board and
relaybox).
Thread size (metric) M5 M6 M8
Max. torque [Nm] 2,2 3,9 9,0
KOMATSU 00-59
--- Page 9 ---
INDEX AND FOREWORD STANDARD TIGHTENING TORQUE TABLE
Thread Width Tightening torque (Nm {kgm})
Nominal No. diameter across flats
(mm) (mm) Range Target
18 18 27 34.3 to 44.1 {3.5 to 4.5} 39.2 {4.0}
20 20 30 44.1 to 53.9 {4.5 to 5.5} 49.0 {5.0}
24 24 32 58.8 to 78.4 {6.0 to 8.0} 68.6 {7.0}
30 30 32 93.1 to 122.5 {9.5 to 12.5} 107.8 {11.0}
33 33 - 107.8 to 147.0 {11.0 to 15.0} 127.4 {13.0}
36 36 36 127.4 to 176.4 {13.0 to 18.0} 151.9 {15.5}
42 42 - 181.3 to 240.1 {18.5 to 24.5} 210.7 {21.5}
52 52 - 274.4 to 367.5 {28.0 to 37.5} 323.4 {33.0}
TABLE OF TIGHTENING TORQUE FOR BOSS PIPING JOINTS WITH FLAT
SEAL (DIN3852)
REMARK
Tighten the pipe joint for boss with the torque shown in the table
below unless otherwise specified.
g0011035
Tightening torque Tightening torque
Thread diam- Width across Thread Width across
eter flats (mm) Target Tolerance diameter flats (mm) Target Tolerance
(Nm) (Nm) (Nm) (Nm)
M12x1.5 25 0/-2,5 G1/8A 20 0/-2
M14x1,5 50 0/-5 G1/4A 50 0/-5
M16x1,5 70 0/-7 G3/8A Varies 80 0/-8
M18x1,5 Varies 90 0/-9 G1/2A depending 100 0/-10
M20x1,5 depending on 130 0/-13 G3/4A on type of 180 0/-18
M22x1,5 type of con- 130 0/-13 G1A connector. 230 0/-23
M26x1,5 nector. 180 0/-18 G1 1/4A 330 0/-33
M27x2 200 0/-20 G1 1/2A 500 0/-50
M33x2 230 0/-23
M42x2 330 0/-33
KOMATSU 00-69
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INDEX AND FOREWORD CONVERSION TABLE
KOMATSU
--- Page 11 ---
SPECIFICATIONS BASIC PROCEDURES OF MAINTENANCE
COOLANT
• River water contains large amounts of calcium and other impurities, so if it is used, scale will stick to the en-
gine and radiator causing a defective heat exchange and overheating.
• Do not use water that is not suitable for drinking.
• When using anti-freeze, always observe the precautions given in the Operation and Maintenance Manual.
• Komatsu machines are supplied with Komatsu original anti-freeze in the coolant when the machine is
shipped. This anti-freeze prevents corrosion in the cooling system. The anti-freeze can be used continuously
for two years or 4000 hours. Therefore, it can be used as it is, even in hot areas.
• Anti- freeze is flammable, so be extremely careful not to expose it to open flame or fire.
• The proportion of anti-freeze to water differs according to the ambient temperature. For details of the mixing
ratios, see Operation Manual: "METHOD FOR CLEANING INSIDE OF COOLING SYSTEM“.
• If the engine overheats, wait for the engine to cool down before adding coolant.
• If the coolant level is low, it will cause overheating and corrosion due to the air in the coolant.
GREASE
• Grease is used to prevent twisting and noise at the joints.
• The nipples not included in the maintenance section are nipples for overhaul, so they need not be lubricated.
If any part becomes stiff after being used for a long time, add grease.
• Always wipe off all of the old grease that is pushed out when greasing. Be particularly careful to wipe off the
old grease in places where sand or dirt in the grease would cause the rotating parts to wear.
STORING OIL AND FUEL
• Keep oil and fuel indoors to prevent any water, dirt or other impurities from penetrating.
• When keeping barrels for a long period, lay the barrel down on its side so that the filler port is at the side (to
prevent moisture from being sucked in).
If barrels have to be stored outside, cover them with a waterproof sheet or take other measures to protect
them.
• To prevent any change in quality during long term storage, be sure to use in the order of 'first in - first out'
(use the oldest oil or fuel first).
KOMATSU 01-9
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STRUCTURE AND FUNCTION ABBREVIATION LIST
Purpose of use (major ap-
Abbrevia-
Actual word spelled out plicable machine (*1), or Explanation
tion
component/system)
A general term for the engineering and its
Information and Com- Communication and
ICT socially applied technology of information pro-
munication Technology electronic control
cessing and communication.
This is a valve that adjusts the fuel intake
IMA Inlet Metering Actuator Engine amount at the pump inlet in order to control the
supply pump fuel discharged volume. (Same
This is a device to detect the angle (or angular
Inertial Measurement
IMU Engine velocity) and acceleration of the 3 axes that
Unit
control motions.
This is a valve that adjusts the fuel intake
amount at the pump inlet in order to control the
IMV Inlet Metering Valve Engine
supply pump combustion discharged volume.
(Same as IMA)
This is a mechanism that burns the blowby gas
Closed Crankcase again by separating oil from blowby gas and re-
CCV Engine
Ventilation turning it to the intake side. It primarily consists
of filters.
Komatsu Catalyzed This is a filter that captures soot in exhaust
KCSF Engine gas.
Soot Filter
This is a catalyst that is used for purifying ex-
Komatsu Diesel haust gas.
DOC Engine
Oxidation Catalyst It is built in to DPF or assembled with the muf-
fler.
This is a component that is used to purify the
Komatsu Diesel Partic- exhaust gas. DOC (catalyst) and KCSF (filter to
DPF Engine
ulate Filter capture soot) are built-in it.
It is installed instead of the conventional muffler.
This is a function that performs braking with the
optimum force and recovers the driving force of
Komatsu Traction Travel and brake
KTCS the wheels by actuating the inter-axle differen-
Control System (HM)
tial lock when the wheels runs idle while the
machine travels on the soft ground.
This is an image display equipment such as a
LCD Liquid Crystal Display Machine monitor monitor in which the liquid crystal elements are
assembled.
This is a semiconductor element that emits light
LED Light Emitting Diode Electronic parts
when the voltage is applied in forward direction.
Local Interconnect Communication and This is one of communication standards that
LIN
Network electronic control are used in the network on the machine.
This is a function that detects differential pres-
LS Load Sensing Hydraulic system sure of pump, and controls discharged volume
corresponding to load.
Low Voltage Communication and This is one of communication standards that
LVDS
Differential electronic control are used in the network on the machine.
This indicates engine intake air flow. This is not
used independently but is used as combined
MAF Mass Air Flow Engine
with sensor. Mass air flow sensor can be called
as MAF sensor.
KOMATSU 10-7
--- Page 13 ---
STRUCTURE AND FUNCTION PREHEATING SYSTEM
FUNCTION OF AUTOMATIC PREHEATING
SYSTEM
• Automatic preheating system is installed for the engine to
start easily in cold weather.
• When the starting switch is turned to "ON" position, the auto-
matic preheating system starts to set the preheating time
automatically corresponding to the coolant water tempera-
ture.
• The preheating pilot lamp on the machine monitor lights up
and the electric glow plugs are energized when the starting
switch is turned to "ON" position.
• Engine controller detects coolant temperature with the tem-
perature sensor and sets the preheating time according to
them (up to 15 sec).
• Pilot lamp on monitor stays lit while preheating is operated.
Keep the starting switch in "ON" position during this time. If
starting switch is turned to "START" position, automatic pre-
heating is canceled.
OPERATION OF AUTOMATIC PREHEAT-
ING SYSTEM
1. When the starting switch is turned to "ON" position, the en-
gine controller starts.
2. The engine controller drives the preheater relay just after
starting switch is turned to "ON" position, and the electric
heater relay operates for electric heater to start preheating
of the engine.
3. The operating time of preheater is shown in the following fig-
ure.
KOMATSU 10-17
--- Page 14 ---
STRUCTURE AND FUNCTION KOMTRAX SYSTEM
KOMTRAX SYSTEM
KOMTRAX SYSTEM DIAGRAM
KOMTRAX system consists of KOMTRAX terminal (controller)
and two antennas (communication and GPS)
FUNCTION OF KOMTRAX SYSTEM
• KOMTRAX system transmits various types of information on
the machine. KOMTRAX administrator sees the information
in the office and supplies various services to the customers.
• KOMTRAX system can transmits the following information.
• Positional information
• Operation information (service meter, odometer, etc.)
• Fuel consumption information
• Machine working condition information
REMARK
To provide the services, you need to establish radio station for
KOMTRAX separately.
KOMATSU 10-27
--- Page 15 ---
STRUCTURE AND FUNCTION COMPONENT PARTS OF CONTROL SYSTEM
Service mode function of machine monitor
These functions are not displayed normally. These are for a
technician to display and set with special switch operation.
These functions are used for special settings, testing, adjusting,
or troubleshooting.
Items available in the service mode are as follows.
Self-define Monitoring
Mechanical Sys Abnormality Record
Abnormality Record
Electrical Sys Abnormality Record
Maintenance Record
Maintenance Mode Setting
Phone Number Entry
Machine Model Selection
Default Option Selection
Unit Selection
Adjustment T/C Device Calibration
REMARK
For operating method of the service mode functions, See
"SERVICE MODE" on page 30-70.
KOMATSU 10-37
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STRUCTURE AND FUNCTION HYDRAULIC SYSTEM
Structure of the pump for steering, work equipment and cooling fan
g0010852
Double pump
1 Pump for steering and work equipment
2 Pump for cooling fan
Specifications of the pumps for steering, work equipment, cooling fan and high flow
Work equipment / Steering pump
Model: CASAPPA KP30.31
Discharged pressure: max. 23,0 MPa {235 kg/cm2}
Standard discharged volume: 61.4 ℓ/min
Cooling fan pump
Model: CASAPPA PL20.8
Discharged pressure: max. 28,0 MPa {285 kg/cm2}
Standard discharged volume: 17,4 ℓ/min
KOMATSU 10-47
--- Page 17 ---
STRUCTURE AND FUNCTION STRUCTURE OF THE HST SYSTEM
Operation of HST pump
• The HST pump is a variable displacement pump, where the
displacement pistons are mounted axially parallel to the
drive shaft. They react against the swash plate.
• The drive shaft is rotated by the engine. The drive shaft is
rigidly connected to the cylinder head.
The cylinder head rotates with the drive shaft. The pistons
(2) are mounted in the cylinder head. The pistons are
mounted on guide shoes, which glide on the swash plate.
Due to the tilted position of the swash plate, this causes an
axial displacement of the pistons in the cylinder head. The
guide shoes are held with oil pressure against the swash
plate.
During rotation the pistons move between bottom dead cen-
tre and top dead centre and back to the start position. In
moving between the dead centres (here the piston changes
its linear direction) the piston completes a stroke. Because
of this oil is sucked in on the inlet port and displaced through
the outlet port. The displaced oil volume depends on the pis-
ton area and the length of stroke.
Suction takes place when the oil fills the increasing cylinder
space. The oil is additionally forced into the cylinder by
charge pump pressure. The returning piston forces the oil
out of the cylinder head through the outlet port.
The swash plate angle can be changed to increase or de-
crease the piston stroke and with this the displaced oil vol-
ume. When the swash plate angle changes over the neutral
position, the pumped direction also changes. Inlet becomes
outlet, outlet becomes inlet.
1. Drive shaft
2. Pistons
3. Piston area
4. Piston displacement
5. Swash plate
6. Operating angle
7. Cylinder head
g0010871
8. Drive shaft
9. Control plate
10. Top dead centre
11. Bottom dead centre
12. Inlet port (rotation as shown)
13. Outlet port (rotation as shown)
KOMATSU 10-57
--- Page 18 ---
STRUCTURE AND FUNCTION STRUCTURE OF THE HST SYSTEM
Function of towing system
For towing the machine, follow the instructions in the operator's
manual.
For towing the machine, the HST motor needs to be bypassed. If
this is not done, rotation of the wheels will be transmitted
through the transfer box to the HST motor (2). The oil displaced
by the motor would be forcing the pump (1) to turn, which may
damage the engine.
This is achieved by activating the towing valve (3) by turning the
lever downwards.
After activating the valve, the oil displaced by the motor (2) is not
flowing through the pump (1), but through the towing valve (3).
In this case, no rotational force is generated in the pump (1) and
a damage of the engine is prevented.
x0001169
KOMATSU 10-67
--- Page 19 ---
STRUCTURE AND FUNCTION STEERING SYSTEM
STEERING SYSTEM
LAYOUT DRAWING OF STEERING SYSTEM
2
1
3
4
x000180
1 Orbitrol valve 3 Steering pump
2 Priority valve 4 Steering cylinder
KOMATSU 10-77
--- Page 20 ---
STRUCTURE AND FUNCTION UNDERCARRIAGE AND FRAME
UNDERCARRIAGE AND FRAME
FRAME, AXLE MOUNT AND CENTER HINGE PIN
Structure of frame, axle mount and center hinge pin general view
A 4
B
6
3
2
7
1
x0001179
1 Front axle 6 Frame lock bolt
2 Front frame 7 Axle mounting bolt
3 Rear frame A Detail see next picture
4 Counterweight B Detail see next picture
KOMATSU 10-87
--- Page 21 ---
STRUCTURE AND FUNCTION CAB AND ITS ATTACHMENTS
TIPPING UP THE OPERATOR'S CAB (STANDARD, WITHOUT TIPPING
CYLINDER)
• Risk of injury! The tipped up operator’s cab can suddenly
lower itself!
• Never enter the raised cabin.
• Never start the engine with the cabin up.
• Never tip up the cabin in strong winds.
1. Park the machine on solid, level ground.
2. Lower the work equipment to the ground and switch off the
engine.
3. Close the cab door.
4. Secure the articulated steering (1) with the locking bolt.
1
NOTICE
The machine has to be positioned as for driving in a straight line,
and the articulated steering has to be secured with the locking
bolt! If the operator's cab is tipped up while the machine is bent,
the front frame may damage the windscreen!
5. Open the engine hood (2).
2
g0010417
KOMATSU 10-97
--- Page 22 ---
20 STANDARD VALUE TABLE
ABBREVIATION LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-2
List of abbreviations used in the text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-2
List of abbreviations used in the circuit diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-7
STANDARD VALUE TABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-8
Standard value table for engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-8
Standard value table for chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-9
TEST CERTIFICATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-11
KOMATSU 20-1
--- Page 23 ---
STANDARD VALUE TABLE TEST CERTIFICATE
TEST CERTIFICATE
Chassis Nº: Customer:
Test temperatures Target Value
1 Cooling water 82±5
°C
Hydraulic oil (drive and working hydraulic, measured in the hydraulic oil
2 50±5
cooler return)
Engine speed Target Value
3 Low idle speed 900±10
a 4 High idle speed 2230±10
rpm
5 Engine speed hydrostat full stall (oil temperature: min.55°c) 2230±10
6 Engine speed working hydraulic+hydrostat full stall 2230±10
7 Start of drive RPM 1050±50
System pressures Target Value
a 8 Work hydraulic pressure 230+5
a 9 Steering hydraulic pressure 180±5
10 Feed pressure (low idle speed and test temperature) bar min. 26
11 Feed pressure (high idle speed and test temperature) max. 30
a 12 Pressure (absolut) machine is full braked forward 455±5