PDF Shop Manual Komatsu WA320-8E0 Wheel Loader - 4 MB
This official shop manual provides complete service and repair information for the Komatsu WA320-8E0 wheel loader.
It is the same guide used by factory-trained technicians, containing detailed diagrams, specifications, and step-by-step instructions.
Covering everything from the engine to the hydraulic system, this manual is essential for troubleshooting, testing, and major overhauls.
Ensure your repairs are done right with this comprehensive resource.
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--- Page 1 ---
SEN06792-06
WHEEL LOADER WA320 -8E0
SERIAL NUMBERS 86025 and up
--- Page 3 ---
Safety Notice for Operation 00 Index and Foreword
Precautions for Slinging Work and When You Make Signals
• Only one appointed worker must make signals and co-workers must communicate with each other fre-
quently. The appointed signaler must make specified signals clearly at a place where he is well seen from
the operator's seat and where he can see the working condition easily. The signaler must always stand in
front of the load and guide the operator safely.
k Do not do the work while the lifted load is in the range where it possibly falls. It is not allowed to
go in the range where the lifted load possibly falls.
k Do not move a load over a person.
k Never step on the load.
k Do not prevent the load from swinging or falling down by holding it simply with the hands.
k The sling workers and assistant workers other than the guide must move to a place where they
are not caught between the load and materials or equipment on the ground or hit by the load
even if the crane starts abruptly.
• When you lift or fix the machine, see “Operation and Maintenance Manual” or “Field Assembly Instruction”.
k Do not lift or fix the machine by the positions where the name plate is not attached.
• When you lift the machine for the disassembly and assembly, follow the instructions on the Disassembly
and Assembly.
• Check the slings before starting sling work.
• Keep putting on gloves during sling work. (Put on leather gloves, if available.)
• Measure the weight of the load by the eye and check its center of gravity.
• Use proper sling corresponding to the weight of the load and method of slinging. If too thick wire ropes are
used to sling a light load, the load may slip and fall.
• Do not sling a load with 1 wire rope alone. If it is slung so, it may rotate and may slip out of the rope. Install
2 or more wire ropes symmetrically.
k Slinging with one rope may cause turning of the load during hoisting, untwisting of the rope, or
slipping of the rope from its original slinging position on the load, which can result in a danger-
ous accident.
• Hanging angle must be 60 ° or smaller as a rule.
• When slinging a heavy load (20kg or heavier), the hanging angle of the rope must be narrower than that of
the hook.
REMARK
When slinging a load with 2 or more ropes, the force sub-
jected to each rope increases with the hanging angle. The
figure below shows the variation of allowable load in kN
{kg} when slinging is made with 2 ropes, each of which is
allowed to sling up to 9.8 kN {1000 kgf} vertically, at vari-
ous hanging angles. When the 2 ropes sling a load verti-
cally, they can sling up to 2000 kg of total weight. This
weight is reduced to 1000 kg when the 2 ropes make a
hanging angle of 120 °. If the 2 ropes sling a 2000 kg load
at a hanging angle of 150 °, each rope is subjected to a
force as large as 39.2 kN {4000kgf} .
• When installing wire ropes to an angular load, apply pads to protect the wire ropes. If the load is slippery,
apply proper material to prevent the wire rope from slipping.
• Use the specified eye bolts and fix wire ropes, chains, etc. to them with shackles, etc.
00-34 WA320-8E0
--- Page 4 ---
00 Index and Foreword Foreword, Safety, Basic Information
How to Disconnect and Connect Slide Lock Type Connector
How to Disconnect Slide Lock Type Connector (FRAMATOME-3, FRAMA-
TOME-2)
1. Slide lock (L1) to the right.
2. While pressing lock (L2), pull out connector (1) toward you.
REMARK
If portion A does not float when lock (L2) is pressed, and if
connector (1) does not come out when it is pulled toward
you, push up portion A with a small flat-head screwdriver
while pressing lock (L2), and then pull out connector (1) to-
ward you.
How to Connect Slide Lock Type Connector (FRAMATOME-3, FRAMATOME-2)
Insert it straight until it clicks.
How to Disconnect Slide Lock Type Connector (FRAMATOME-24)
1. Slide down lock (red) (L1).
WA320-8E0 00-69
--- Page 5 ---
Specification Drawing 01 Specifications
Item Unit WA320-8E0
D Overall width mm 2590
E Minimum ground clearance mm 425
Bucket width
F North America specification 2740
mm
EU and Turkey Specification 2750
Bucket tip/ BOC tip
North America speci-
Dumping clearance 2970/2880
G fication
(*3) mm
EU and Turkey
2905/2835
Specification
Bucket tip/ BOC tip
North America speci-
960/1000
H Dumping reach (*3) fication
mm
EU and Turkey
985/1020
Specification
Forward tilt angle of the bucket (maximum
I degree 47
height)
Bucket tip/ BOC tip
North America speci-
6275/6310
Minimum turning radi- fication
mm
us EU and Turkey
6300/6330
Specification
Center of outside tire mm 5380
Allowable towing load kN {kg} 112 {11415}
1st (Forward/Reverse) 1.0 to 13.0/1.0 to 13.0
2nd (Forward/Reverse) 13.0/13.0
Travel speed km/h
3rd (Forward/Reverse) 18.7/18.7
4th (Forward/Reverse) 38.0/38.0
*1: Indicates the value of the bare engine (without cooling fan).
*2: Indicates the value at the minimum cooling fan speed.
REMARK
• The engine rated horsepower is indicated in the net value and gross value. Gross denotes the rated horse-
power measured on the basic engine unit. Net denotes the value of an engine which is measured under the
condition almost the same as that of the time when it would be installed on a machine.
• The rated horsepower (net) at the maximum cooling fan speed is the following value.
112 kW/151 HP{2100 min-1/2100 rpm}
*3: Indicates the value when the forward tilt angle of the bucket is 45 °.
BOC
Abbreviation for Bolt On Cutting edge
01-10 WA320-8E0
--- Page 6 ---
10 Structure and Function Function of Urea SCR System
Inducement Strategy for Abnormality Recurrence
• The Urea SCR system continuously monitors its operation conditions and stores information on inappropri-
ate operations including malfunctions.
• The stored information is utilized to monitor recurrences of abnormalities, “Abnormality Counter”. “Abnor-
mality Counter” is required by the authorities. The abnormality counting spans 40 hours and it monitors the
abnormalities that trigger Inducement other than the amount of DEF in the tank.
• If another abnormality/abnormalities is detected within 40 hours after the previous abnormalities were cor-
rected, regardless of the level of the previous Inducement and whether the new abnormality/abnormalities
is the same as the previous ones or not, it is judged as a recurrence.
• If a recurrence occurs, the Inducement strategy will be activated.
• Inducement in the recurrence resumes counting time at the time when the previous abnormalities were cor-
rected if the previous Inducement is in “Warning”, “Continuous Warning” or “Low-Level Inducement”. The
alerts resume the previous Inducement.
• If the time the previous abnormalities were corrected is in “Severe Inducement”, Inducement in the recur-
rence starts from “Low-Level Inducement” but the remaining time to “Severe Inducement” is 1 hour or 2
hours depending on abnormalities. If the 1 hour or 2 hours are used up without correcting the new abnor-
malities, Inducement will advance to “Severe Inducement” and engine power will be derated heavily.
WA320-8E0 10-25
--- Page 7 ---
Component Parts of Engine System 10 Structure and Function
EGR Valve
EGR
Abbreviation for Exhaust Gas Recirculation
Structure of EGR Valve
REMARK
The shape is subject to machine models.
Sectional View
A: EGR gas inlet (from EGR cooler) D: Servo drive oil outlet
B: EGR gas outlet (to intake manifold) E: VGT control hydraulic outlet
C: Servo drive oil inlet F: VGT drive pressure outlet
1: Valve 5: Spring
2: Spring 6: EGR valve lift sensor
3: Power piston 7: EPC valve (for EGR)
4: Spool 8: EPC valve (for VGT)
Structure
• EGR valve consists of the EGR gas flow control mechanism and EPC valve.
• There are 2 EPC valves, one for the EGR valve and the other for VGT.
10-60 WA320-8E0
--- Page 8 ---
10 Structure and Function Machine Monitor System
Machine Monitor
Displays the machine condition to the operator.
Monitor Controller
Obtains the condition data of various sections of the machine monitored with sensors and switches and pro-
cesses them. Communicates the network information with each controller.
Switch Panel
Accepts operations of the operator.
WA320-8E0 10-95
--- Page 9 ---
Component Parts of Control System 10 Structure and Function
HST Controller
HST
Abbreviation for Hydro Static Transmission
Structure of HST Controller
General View
Function of HST Controller
Real Time Monitoring Function
The conditions of the input and output signals of the controller can be checked with monitoring function of the
machine monitor.
REMARK
For the monitoring procedure, see Testing and Adjusting, “Set and Operate Machine Monitor”.
Self-Diagnosis Function
• HST controller constantly monitors the input and output conditions and performs self-diagnosis of the sys-
tem.
• If any abnormality is detected by self-diagnosis, the information is transmitted through the network to the
machine monitor.
• The occurrence of an abnormality can be checked on the machine monitor and KOMTRAX.
10-130 WA320-8E0
--- Page 10 ---
10 Structure and Function Component Parts of Hydraulic System
Operation When Load is Balanced with Pump Pressure (PA)
1. As the servo piston (15) moves, the lever (1) moves to the right and the spring (2) is compressed and its
reaction force is increased. Consequently, the spool (5) moves to the right and the port (C) is disconnected
from the port (B), and the drain pressure port (D) and the drain pressure port (C) are connected.
2. As a result, the pressure in the port (C) lowers, the piston pressure is decreased, and the servo piston (15)
stops moving to the right.
3. Accordingly, the stop position (= pump discharged volume) of the servo piston (15) is determined by the
position where the thrust which is caused by the pressure (PA) applied to the piston (7) is balanced with the
force of the spring (2) acting through the spool (5). (Fig. 3)
WA320-8E0 10-165
--- Page 11 ---
Directional Selector Switch Control Function 10 Structure and Function
Directional Selector Switch Control Function
The switch to select travel direction is provided on the side of the work equipment control lever. It is independent
from the standard directional lever, so that the operator can select the travel direction with his/her right hand.
Change to Directional Selector Switch
• When only the directional lever is used, the directional lever input signal is equal to recognition of travel
direction. Since the another switch for directional selection is added, selector switch is provided to shift the
actuation.
REMARK
The directional selector switch actuation switch actuates the directional selector switch. However, the direc-
tional lever (standard directional lever) is given the priority for the operation.
• The directional selector switch is actuated when the standard directional lever is in N (Neutral), the direc-
tional selector switch actuation switch is in N (Neutral). Then, the directional selector switch is enabled for
selecting travel direction.
REMARK
• When the travel direction can be changed with the directional selector switch, the directional selection
pilot lamp on the machine monitor lights up in green.
• If the directional selector switch actuation switch is turned ON or OFF when either is other than N (Neu-
tral), the directional selection pilot lamp on the machine monitor lights up in yellow and the caution lamp
lights up.
• The standard directional lever is given the priority for the operation if the standard directional lever is set in
a position other than N (F or R) even when the directional selector switch is enabled. The travel direction is
set corresponding to the operation of standard directional lever, the directional operation is not selected
normally. The directional selection pilot lamp on the machine monitor lights up in yellow and the caution
lamp lights up.
REMARK
If directional selection pilot lamp lights up in yellow, set both of the standard directional lever and the direc-
tional selector switch in N (Neutral), otherwise caution does not stop and the directional selector switch
does not work.
• The above description is shown in the table below.
Directional
Directional
selector
selector Monitoring op-
switch
FNR recogni- switch ena- eration
Mode Condition wrong op-
tion bled/disa-
eration (Reference)
bled state
state out-
output
put
Directional lever switch: (F or N or
R) The pilot lamp
Directional lever Subject to di- OFF OFF is not lit.
Directional selector switch: (N)
(normal) rectional lever (Disabled) (Absence) Buzzer stops
Directional selector switch actua- sounding
tion switch: (OFF)
Directional selec- Directional lever switch: (N)
The pilot lamp
tor switch actua- Directional selector switch: (F or N Subject to the ON OFF is lit in green.
tion switch: (nor- or R) directional se-
mal (directional lector switch (Enabled) (Absence) Buzzer stops
Directional selector switch actua- sounding
selector switch) tion switch: (ON)
10-200 WA320-8E0
--- Page 12 ---
10 Structure and Function Component Parts of Power Train System
Bypass Shuttle Valve of HST Pump
Structure of Bypass Shuttle Valve of HST Pump
Sectional View
1: Piston 3: Stopper
2: Plug
Function of Bypass Shuttle Valve of HST Pump
Function as Bypass Valve
When the plug (2) is loosened, the bypass shuttle valve connects the forward travel high-pressure circuit and
reverse travel high-pressure circuit of HST pump. By this operation, the machine can be moved by towing even
if the pump swash plate is locked in neutral because of a failure, etc.
Function as Shuttle Valve
The bypass shuttle valve sends oil to the cut-off valve from whichever is the higher oil pressure of the forward
travel high-pressure circuit or reverse travel high-pressure circuit.
WA320-8E0 10-235
--- Page 13 ---
Component Parts of Power Train System 10 Structure and Function
10. The control switch (5) has the Hall element (18). The Hall elements are arranged on the circuit board to be
matched to each position of speed range selection.
11. If the combination switch senses that the magnet (17) comes just above the Hall element (18) at each posi-
tion, it outputs “1st”, “2nd”, “3rd”, or “4th” signal according to the operation of the speed range selector
switch (13).
10-270 WA320-8E0
--- Page 14 ---
10 Structure and Function Steering Column
Steering Column
Structure of Steering Column
General View
1: Steering wheel 4: Short column
2: Steering column 5: Orbitrol valve
3: Steering tilt lock lever
WA320-8E0 10-305
--- Page 15 ---
Component Parts of Brake System 10 Structure and Function
Operation of Brake
When Brake is Applied
1. When brake pedal is depressed, pressurized oil (P) sup-
plied from the hydraulic tank through the pump and brake
charge valve flows through the oil passage in the brake
cylinder to push piston (2) to the left.
2. Rotation of discs (4) between piston (2), plates (3), and
end plate (5) are stopped, and the brake is applied to the
machine.
*
When Brake is Released
1. When oil pressure is released, piston (2) is returned by the
reaction force of spring (8). As a result, clearance is made
between plates (3) and end plate (5), and brake is re-
leased.
2. Linings installed to discs (4) are grooved in a check pat-
tern, and oil flows in the grooves to cool the linings while
discs (4) are turning.
*
10-340 WA320-8E0
--- Page 16 ---
20 Standard Value Table Standard Value Table for Machine: WA320-8E0
Transfer
Machine model WA320-8E0
Engine SAA6D107E-3
Standard value for
Item Measurement condition Unit Repair limit
new machine
• HST oil temperature45 to 55 °C
• Speed range selector switch: 3rd or
4th
Clutch control MPa 3.33±0.20 3.33 (+0.20/-0.59)
pressure • Directional lever: FORWARD posi-
{kgf/cm2} {34±2.0 } {34 (+2/-6) }
tion
• During the travel at 10 km/h or fast-
er)
Travel Speed
Machine model WA320-8E0
Engine SAA6D107E-3
Standard value for
Item Measurement condition Unit Repair limit
new machine
Gear speed: F1 1 (+0.4/-0.5) Max. 1.5
Gear speed: F2 13±0.7 13±0.9
Gear speed: F3 • Road surface state: Flat, level, 18.7±0.9 18.7±1.3
Gear speed: F4 straight, dry, and paved 38±1.9 38 (+1.9/-2.7)
km/h
Gear speed: R1 • Bucket: No load 1 (+0.4/-0.5) Max. 1.5
Gear speed: R2 • Traction control switch: OFF (MAX) 13±0.7 13±0.9
Gear speed: R3 18.7±0.9 18.7±1.3
Gear speed: R4 38±1.9 38 (+1.9/-2.7)
Accumulator
Machine model WA320-8E0
Engine SAA6D107E-3
Standard value for
Item Measurement condition Unit Repair limit
new machine
When brake
Charge cut-in oil pressure MPa 5.9 (+0.5/0) 5.9 (+0.98/-0.5)
pressure • HST oil tempera- caution lamp {kgf/cm2} {60 (+5/0) } {60 (+10/-5) }
ture45 to 55 °C is off.
• Accelerator pedal: When the oil
Not depressed (Low pressure MPa 9.8 (+0.98/0) 9.8 (+1.5/-0.5)
Charge cut-out
idle) turned from in-
pressure {kgf/cm2} {100 (+10/0) } {100 (+15/-5) }
crease to de-
crease.
WA320-8E0 20-19
--- Page 17 ---
Examine Engine Speed 30 Testing and Adjusting
2. Select “Pre-defined Monitoring” (01/25) or the following
monitoring items, and display it by referring to “Set and
Operate Machine Monitor”.
Monitoring code: 01002 “Engine Speed”
Monitoring code: 04107 “Coolant Temperature”
Monitoring code: 04401 “HST Oil Temperature”
3. Raise the coolant temperature and the HST oil tempera-
ture to the specified range.
4. Depress the accelerator pedal gradually. Test the engine
speed when the accelerator pedal is depressed to the full
stroke (high idle) and the bucket is tilted back at the same time.
For standard values, see “20 Standard Value Table”.
How to Examine Engine Speed at Full Stall (HST Stall + Hydraulic Stall)
1. Start the engine.
2. Raise the coolant temperature and the HST oil temperature to the specified range.
3. Display the “HST Pump Stall Pressure Check screen ”
screen by referring to “Set and Operate Machine Monitor”,
“ADJUSTMENT MENU (HST Pump Stall Pressure
Check)”.
4. Set the traction control function to OFF (MAX).
REMARK
When the traction control function is set to OFF (MAX), the
pilot lamp shown in the drawing lights up on the monitor.
5. Set the speed range to 2nd by using the speed range se-
lector switch.
6. While depressing the brake, set the directional lever to
FORWARD.
7. Depress the accelerator pedal gradually. Test the engine
speed when the accelerator pedal is depressed to the full
stroke (high idle) and the bucket is tilted back at the same time.
k Keep depressing the brake pedal fully.
NOTICE
Do not keep stalling the HST for more than 20 seconds. Take care that HST oil temperature does not
exceed 120 °C.
REMARK
Measure the engine speed with HST stalled 2 or 3 times.
For standard values, see “20 Standard Value Table”.
30-26 WA320-8E0
--- Page 18 ---
30 Testing and Adjusting Examine Fuel Discharge, Return and Leakage
3. Install cap nut A1 of tester kit A to fuel return hose side
with joint bolt (5) to prevent the fuel from flowing out.
REMARK
Seal washer D must be installed when installing cap nut
A1.
4. Install joint B to the supply pump side with joint bolt C.
REMARK
When installing joint B and joint bolt (C, be sure to install
3 Joint bolt C:
seal washer D.
19.6 to 29.4 Nm {2.0 to 3.0 kgfm}
5. Install hose J to joint B.
REMARK
Adjust the route of hose J so that it does not slack, and put its end in measuring cylinder H.
6. Start and run the engine with the accelerator pedal re-
leased (low idle), and measure the return rate from the
supply pump with measuring cylinder H for 30 seconds.
For standard values, see Standard Value Table, “Standard
Value Table for Engine”.
NOTICE
If the engine cannot be started, you may perform the
measurement while rotating the engine by using the
starting motor, but do not crank the engine for more
than 20 seconds continuously to protect the starting
motor. “Crank the engine for 15 seconds, stop for 15
seconds and then crank it again for 15 seconds.” Per-
form the measurement according to this procedure.
After finishing the test, remove the testing tools and restore the machine.
3 Bracket mounting bolt (4):
24±4 Nm {2.45±0.41 kgfm}
3 Joint bolt (5):
19.6 to 29.4 Nm {2.0 to 3.0 kgfm}
WA320-8E0 30-61
--- Page 19 ---
Examine SCR Related Functions 30 Testing and Adjusting
8. Check that “0” in the “Test State” column is flashing.
REMARK
Flashing of “0” indicates “Wait for the start (default)”, and
the test can be performed. When the display is not “0”,
perform the required action according to “Parameter list of
test state”.
9. Press UP switch (10) to start “DEF Line Heater Relay 1
Test”.
UP switch (10): Starts “DEF Line Heater Relay 1 Test”
DOWN switch (11): Stops “DEF Line Heater Relay 1 Test”
(When “STOP” is displayed.)
RETURN switch (12): Returns the screen to the “SCR
Service Test” screen
NOTICE
• If the display of “Test State” does not change to
“10” and the test does not start even by pressing
UP switch (10), turn starting switch to OFF posi-
tion, and repeat the testing procedure from step 6.
• If you turn the starting switch to OFF position by
mistake during test, do not turn starting switch to
ON position immediately. Check that system oper-
ating lamp is off, and then turn the starting switch
to ON position again after engine controller shuts
down.
• The engine controller cannot detect a KOMNET
communication error which does not remain for
one second, and the test may continue even when
the machine monitor does not continue the test
(standard screen). In such a case, turn the starting
switch to OFF position to shut down the engine
controller, and the system operating lamp goes
out, and then the test is reset.
REMARK
• Display of “Test State” changes to flashing of “10”, and display of “Remaining Time to Start Test” is
counted down from “60 sec” to “0 sec”, and when it reaches to “0 sec”, the power is supplied automati-
cally.
• When the display of “Test State” is “11” to “41”, perform the required action according to the “Parameter
list of test state”.
• When the display of “Remaining Time to Start Test” becomes “0 sec”, “DEF Line Heater 1 Command” is
“ON” and the voltage is outputted to the heater relay.
• The heater relay operates 900 seconds at maximum, and its remaining operable time is displayed as
“Remaining Permitted Test Time”.
• When the sum of “Remaining Time to Start Test” (1 min) + Heater relay operating time exceeds 16 mi-
nutes after UP switch (10) is pressed, the test stops automatically.
10. Measure the voltage between pin 1 and pin 2.
30-96 WA320-8E0
--- Page 20 ---
30 Testing and Adjusting Examine Steering Wheel
Steering System
Examine Steering Wheel
Tools to Examine Steering Wheel
Symbol Part No. Part name Q'ty Remarks
A 79A-264-0021 Push-pull scale 1
k Place the machine on a level ground, lower the work equipment to the ground, set the parking brake
switch in PARKING (P) position and work equipment lock switch in LOCK position, and stop the en-
gine.
For testing of the steering wheel to perform troubleshooting or others, refer to this section.
How to Examine Steering Wheel
Examine Play of Steering Wheel
Check this item under the following conditions.
• Engine: Stopped
• Machine posture: Straight travel
1. Move the steering wheel in both directions 2 or 3 times,
check the neutrality of the steering mechanism, and put a
mark (a) to the outer frame of the machine monitor.
2. Rotate the steering wheel to the right, and put a mark (b)
to the point of the steering wheel vertically above the mark
(a) when you feel heavier in operating the steering wheel.
3. Rotate the steering wheel to the left (opposite to step 2),
and put a mark (c) to the point of the steering wheel verti-
cally above the mark (a) when you feel heavier in operat-
ing the steering wheel. Measure the moving distance be-
tween the marks (b) and (c) as the linear distance.
For standard values, see “20 Standard Value Table”.
How to Examine the Steering Wheel Operating Force
Check this item under the following conditions.
• Road surface: Flat, level, paved and dried
• Engine coolant temperature: 60 to 100 °C
• HST oil temperature: 45 to 55 °C
• Tire inflation pressure: Specified pressure
• Bucket: No load
WA320-8E0 30-131
--- Page 21 ---
Examine and Adjust Work Equipment PPC Oil Pressure 30 Testing and Adjusting
5. Test the oil pressure when the accelerator pedal is depressed (high idle) and the work equipment control
lever is operated.
For standard values, see “20 Standard Value Table”.