PDF Shop Manual Komatsu WA320-6 Wheel Loader - 18 MB
The official shop manual for the Komatsu WA320-6 wheel loader is a comprehensive resource for service and repair.
It provides mechanics with detailed instructions for troubleshooting, disassembly, and assembly of all major components.
With technical data, specifications, and clear diagrams, this manual is essential for performing accurate and efficient repairs.
Keep your wheel loader operating at its best with this factory guide.
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--- Page 1 ---
VENBM27500
WHEEL LOADER WA320 -7
SERIAL NUMBERS H01051 and up
80001 and up
--- Page 3 ---
00 Index and foreword
Foreword, safety and general information
• Keep putting on the gloves during sling work. • Apply wire ropes to the middle part of the hook.
(Put on the leather gloves, if available.)
a Slinging near the tip of the hook may cause
• Measure the weight of the load by the eye and
the rope to slip off the hook during hoisting.
check its center of gravity.
The strength of the hook is maximum at its
• Use the proper sling according to the weight of
central part.
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 only. If do so,
the load may rotate or the sling gets loose and
the sling may slip off. 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 dangerous accident.
• Hanging angle must be 60 deg. or smaller as a • Do not use twisted or kinked wire ropes.
rule. • When slinging up a load, observe the following.
• When hanging a heavy load (25kg or heavier),
1. Wind up the rope slowly until the wire rope
the hanging angle of the rope must be narrower
tensions. When putting your hands on the
than that of the hook.
wire ropes, do not grasp them but press them
a When slinging a load with 2 ropes or more, down from above. If you grasp them, your
the larger the hanging angle is, the larger the fingers may be caught.
tension of each rope. The figure bellow 2. After the wire ropes are stretched, stop the
shows the variation of allowable load in kg crane and check the condition of the slung
when hoisting is made with 2 ropes, each of load, wire ropes, and pads.
which is allowed to sling up to 9.8 kN 3. If the load is unstable or the wire rope or
{1,000kg} a load vertically, at various chains are twisted, lower the load and lift it
hanging angles. When the 2 ropes sling a up again.
load vertically, up to 2,000 kg of total weight 4. Do not lift up the load at an angle.
can be suspended. This weight is reduced to • When lowering a load, pay attention to the
1,000 kg when the 2 ropes make a hanging following.
angle of 120 deg.. If the 2 ropes sling a 2,000 1. When lifting down a load, stop it temporarily
kg load at a hanging angle of 150 deg., each at 30 cm above the floor, and then lower it
rope is subjected to a force as large as 4,000 slowly.
kg. 2. Check that the load is stable, and then
remove the sling.
3. Remove kinks and dirt from the wire ropes
and chains used for the sling work, and put
them in the specified place.
Precautions for using mobile crane
a Read the Operation and Maintenance Manual of
the crane carefully in advance and operate the
crane safely.
Precautions for using overhead traveling crane
k The hoist or crane must be used to sling the
components weighing 25 kg or heavier. A
• When installing wire ropes to an angular load,
part weighing 25 kg or heavier in
apply pads to protect the wire ropes. If the load
"disassembly and assembly" section is
is slippery, apply proper material to prevent the
wire rope from slipping. indicated with the symbol of 4 .
• Use the specified eye bolts and fix wire ropes,
chains, etc. to them with shackles, etc.
WA320-7 00-19
--- Page 4 ---
00 Index and foreword
Foreword, safety and general information
2. While pressing lock (L2), pull out connector (1).
Handling of connectors used on engine
Slide, lock type
(FRAMATOME-3, FRAMATOME-2)
Disconnection
1. Slide lock (L1) to the right.
2. While pressing lock (L2), pull out connector (1)
toward you.
a In the case that even if lock (L2) is pressed,
connector (1) cannot be pulled out toward
you unless part A floats, float part A with a
small flat-head screwdriver while pressing
lock (L2), and then pull out connector (1)
toward you.
a Lock (L2) is located in the back of connector
(1).
Connection
1. Insert the connector securely until a click is Connection
heard.
1. Insert the connector securely until a click is
(FRAMATOME-24)
heard.
Disconnection
1. Slide down lock (red) (L1). Pull lock type
(PACKARD-2)
Disconnection
1. Disconnect the connector (2) by pulling lock (B)
(on the wiring harness side) of connector (2)
outward.
WA320-7 00-39
--- Page 5 ---
00 Index and foreword
Foreword, safety and general information
Purpose of use (major
Abbrevia- Actual word spelled applicable machine (*), or Explanation
tion out equipment/device)
Transmission Proportional electromagnetic valve that
Electronic Control
ECMV gradually increases oil pressure to engage
Modulation Valve (D, HD, WA, etc.)
clutch and reduces transmission shock.
Electronically This system ensures smooth high-speed
Travel travel by absorbing vibration of machine
ECSS Controlled Suspension
System (WA) during travel with hydraulic spring effect of
accumulator.
Electronic control device uses the signals
from the sensors on the machine. This signal
ECU Electronic Control Unit Electronic control system indicates the optimum actuation to the
actuators. (Same as E.C.M.)
This function recirculates part of exhaust gas
Exhaust Gas Engine to combustion chamber in order to reduce
EGR
Recirculation combustion temperature, controls emission of
NOx.
Equipment This system allows data (filter, oil replacement
Management interval, malfunctions on machine, failure
EMMS Machine monitor
Monitoring System code, and failure history) from each sensor on
the machine to be checked on the monitor.
Electromagnetic This mechanism allows actuators to be
EPC Hydraulic system
Proportional Control operated in proportion to the current supplied.
This structure protects the operator's head
from falling objects. (Falling Object Protective
Falling Object Cab and canopy Structure)
FOPS
Protective Structure
This performance is standardized as ISO
3449.
Forward-Neutral- Operation
F-N-R Forward-Neutral-Reverse
Reverse
Global Navigation A general term for positioning system using
GNSS Satellite System Communication satellites such as GPS, GALILEO, etc.
Communication
Global Positioning This system uses satellites to determine the
GPS System (KOMTRAX, KOMTRAX current location on the earth.
Plus)
This function uses a combination of hydraulic
Steering motor and bevel shaft to control difference in
Hydrostatic Steering
HSS travel speed of right and left tracks.
System (D) Accordingly machine can turn without using
steering clutch.
Transmission This function uses a combination of hydraulic
Hydro Static pump and hydraulic motor to shift the speed
HST
Transmission (D, WA) range steplessly without using gears.
Information and A general term for the engineering and its
Communication Intelligent Machine socially applied technology of information
ICT
Technology Control processing and communication.
This valve is installed at inlet port of pump,
Inlet Metering Actuator Engine and it adjusts fuel intake amount in order to
IMA
control fuel discharge of supply pump. Same
as I.M.V.
This is a device to detect the angular velocity
Inertial Measurement Intelligent Machine
IMU and acceleration of the 3 axes that control
Unit Control
motions.
This valve is installed at inlet port of pump,
and it adjusts fuel intake amount in order to
IMV Inlet Metering Valve Engine
control fuel discharge of supply pump. Same
as I.M.V. (I.M.A.)
This mechanism separates oil in blowby gas
Komatsu Closed Engine and returns it to the intake side to afterburn it
KCCV
Crankcase Ventilation there. It primarily consists of filters.
WA320-7 00-59
--- Page 6 ---
01 Specification
Specifications
Machine model WA320-7
Unit
Serial No. H01051 and up, 80001 and up
Hydraulic system
Steering cylinder
Type — Double-acting piston type
C ylinde r bore mm 70
Piston rod diameter mm 40
Stroke mm 453
Max. distance between pins mm 1,271
Min. distance between pins mm 818
Lift cylinder
Type — Double-acting piston type
C ylinde r bore mm 120
Piston rod diameter mm 75
Stroke mm 729
Max. distance between pins mm 2,056
Min. distance between pins mm 1,327
Bucket cylinder
Type — Double-acting piston type
C ylinde r bore mm 150
Piston rod diameter mm 110
Stroke mm 558
Max. distance between pins mm 1,912
Min. distance between pins mm 1,354
Work equipment
Link type — PZ-bar link
Shape of bucket cutting edge — Straight cutting edge with BOC
WA320-7 01-11
--- Page 7 ---
10 Structure and function
KVGT
When nozzle ring is open
• At high engine speeds, exhaust gas inlet passage (P) is widened (L2).
• As the engine speed and the turbine inlet pressure (exhaust gas pressure) increases, exhaust gas inlet
passage (P) widens (L2) to effectively apply the exhaust gas pressure to turbine impeller (11).
a Nozzle ring (7), vane (6), and push rod (8) are integrated and slide together but do not rotate.
a KVGT position sensor is installed to hydraulic actuator (3). The KVGT position sensor is calibrated
together with the variable mechanism in the KVGT, and values are stored in the memory inside the KVGT
position sensor. If any of the hydraulic actuator (3), KVGT position sensor, or KVGT body fails, replace the
whole KVGT.
WA320-7 10-9
--- Page 8 ---
10 Structure and function
Cooling system
9. Aftercooler inlet hose
10. Condenser
11. Condenser opening and closing bracket
12. Radiator outlet hose
13. Aftercooler outlet hose
14. Transfer oil cooler inlet
15. Transfer oil cooler outlet
16. Reservoir tank
17. Brake accumulator charge valve
18. Strainer
19. Cooling fan motor
20. Fan guard
21. Transfer oil cooler
22. Oil cooler outlet hose
23. Cooling fan
Outline
• Cooling fan motor (19) installed to the rear of the machine is driven by the solenoid valve in the cooling fan
motor with oil pressure from brake/ cooling fan pump (2).
Specifications (WA320-B000-030-K-00-A)
Radiator Oil cooler Aftercooler
Core type Rectangle corrugated Rectangle corrugated Rectangle corrugated
aluminum aluminum aluminum
Fin pitch (mm) 6.0/2 6.0/2 6.0/2
Total heat dissipation area (m2) 37.1 4.05 x 3 8.19
Pressure valve cracking
70 ± 15
pressure - -
{0.7 ± 0.15}
(kPa {kg/cm2})
Vacuum valve cracking pressure 0 to 5
- -
(kPa {kg/cm2}) { 0 to 0.05}
WA320-7 10-29
--- Page 9 ---
10 Structure and function
HST pump
Low pressure oil relief valve (WA320-C2Y5-041-K-00-A)
1. Plug
2. Valve Piston
3. Shim
4. Spring
Function (WA320-C2Y5-042-K-00-A)
• This valve is installed to the HST pump and drains the oil into the hydraulic tank when the oil pressure in
the low-pressure side circuit between the HST pump and HST motor increases above the set pressure.
By this operation, the HST pump charge circuit pressure is set for protection of the circuit.
Operation (WA320-C2Y5-044-K-00-A)
• Port (A) is connected to HST pump charge circuit and port (B) is connected to the drain circuit.
• When port (A) is below the set pressure, no oil flows into port (B).
• When the oil pressure in port (A) exceeds the set pressure, valve piston (2) is pushed to the right to relieve
the oil pressure in chamber (A) to port (B) and decrease the oil pressure in chamber (A).
• The set pressure is adjustable by increasing or decreasing the reaction force of spring (4).
• To change the set pressure, loosen plug (1) and adjust shim (3). If shims are increased, the set pressure
rises. If shims are reduced, the set pressure lowers.
WA320-7 10-49
--- Page 10 ---
10 Structure and function
Transfer
Power transmitting route (HM300-CF60-001-K-01-A)
Low speed mode (WA320-CF60-052-K-00-A)
Transfer clutch (1) is engaged to transmit the power of both HST motor 1 (2) and HST motor 2 (3).
Power of HST motor 1 (2) Power of HST motor 2 (3)
O O
Input shaft (4) O
O O
Sun gear (5) O
O O
Planetary pinion (6) O
O O
Carrier (7) O
O O
Motor 1 gear (8) Motor 2 gear (9)
O O
Output gear (10) i i
O
Output shaft (11)
WA320-7 10-69
--- Page 11 ---
10 Structure and function
Layout of steering devices
Steering system (ALL-F000-001-K-00-A)
Layout of steering devices (WA320-DT00-04D-K-00-A)
1. Steering cylinder (R.H.)
2. Orbitrol valve
3. Emergency steering valve (with emergency steering system)
4. Priority valve
5. HST pressure sensor (B)
6. HST pressure sensor (A)
7. Steering and work equipment pump
8. Steering and work equipment pump pressure sensor
9. Cushion valve
10. Steering cylinder (L.H.)
WA320-7 10-89
--- Page 12 ---
10 Structure and function
Brake accumulator charge valve
When oil is supplied to accumulator (cut-in state)
• When the accumulator pressure decreases, the pressure in port (E) decreases, plunger (1) moves to the
left, and unload relief valve (2) closes the drain circuit.
• The oil pressures in port (F) and spring chamber of unload valve (3) increase and unload valve (3) moves
to the left.
• Ports (C) and (B) open and the oil from the pump flows to port (B).
• When the oil pressure in port (B) exceeds the set pressure of check valve (4), check valve (4) is pushed
open and the oil flows into the accumulator through port (E). The replenishment pressure to the
accumulator is determined by the set pressure of check valve (4).
• The quantity of oil supplied to the accumulator is constant, regardless of the engine speed, and the excess
flows through port (A) to the cooling fan motor.
• Shuttle valve (5) supplies oil to the accumulator of lower pressure first.
WA320-7 10-109
--- Page 13 ---
10 Structure and function
Tire
Tire (WA320-DW60-041-K-00-A)
This machine has the following features by employing radial tires.
• High grip
• High operator comfort
• Low puncture rate
• Less uneven wear
• Improved fuel economy
• Long life
• Less damage on machine
• Less heat generation
Comparison of structures and characteristics of tires
Radial tire
Structure
• The cords composing carcass (1) are arranged at right angles (radially) to the center line of tread (T).
• Tread (T) is stabilized and protected by several strong belts (2).
• Side wall (W) and tread (T) are independent structurally from each other.
Gripping characteristics
• Even when the tire is deflected by the load, it makes little unnecessary movement and grips the ground
stably and securely.
Deflection characteristics
• When the tire is loaded, only its side wall (W) is deflected and tread (T) composed of strong belts (2)
maintains independent stability.
WA320-7 10-129
--- Page 14 ---
10 Structure and function
Steering and work equipment pump
When balanced
(Fig. 3)
• As servo piston (15) moves, lever (1) moves to the right and spring (2) is compressed and spring force is
increased. Consequently, spool (5) moves to the right and port (C) is disconnected from port (B) and
connected to drain pressure port (D).
• As a result, the pressure in port (C) lowers and the piston pressure is decreased and servo piston (15)
stops moving to the right.
• Accordingly, the stop position (= pump discharge) of servo piston (15) is determined by the position where
the thrust caused by pressure (PA) applied to piston (7) is balanced with the spring force of spring (2)
acting through spool (5). (Fig. 3)
WA320-7 10-149
--- Page 15 ---
10 Structure and function
Hydraulic circuit diagram and names of valves
Pressure compensation valve (WA320-C790-040-P-00-A)
WA320-7 10-169
--- Page 16 ---
10 Structure and function
Work equipment PPC valve
When control lever is at "FLOAT" position
• When rod (4) and piston (9) on "LOWER" side of port (P4) are pushed down with disc (5), detent operation
starts before the stroke end. (The operating effort of the lever increases)
• When rod (4) is further pushed down, the detent operates to keep the lever in "FLOAT" state even if it is
released.
• At this time, the control valve moves to the "FLOAT" position to float the bucket.
When "FLOAT" state is canceled
• When disc (5) is returned from "FLOAT" position, it is pushed down by a force larger than the pulling force
of the solenoid.
• Or when the solenoid current is turned OFF (de-energized), "FLOAT" state is canceled and the lever is
returned to "NEUTRAL" position.
• The above operation is also performed when the boom is raised or the bucket is tilted.
WA320-7 10-189
--- Page 17 ---
10 Structure and function
System operating lamp function
System operating lamp function (WA320-AW1Q-051-K-00-A)
1. Battery disconnect switch
2. Battery
3. System operating lamp
4. Machine monitor
5. Engine controller
6. HST controller
7. KOMTRAX terminal
Function
• You can prevent an abnormal end due to cut-off of the battery power supply circuit while the controllers are
in operation by checking the operating status of machine monitor (4), controllers (5), (6), and (7) with
system operating lamp (3).
a Before cutting off the battery power supply circuit, turn the starting switch to "OFF" position, and check that
system operating lamp (3) goes off, then turn battery disconnect switch (1) to "OFF" position.
a If you turn battery disconnect switch (1) to "OFF" position (battery power supply circuit is cut off) while
system operating lamp (3) is ON, data lost error of machine monitor (4), controllers (5), (6), and (7) can
occur. Do not operate battery disconnect switch (1) while system operating lamp (3) is ON.
a System operating lamp (3) goes off in 2 minutes after the starting switch is turned to "OFF" position.
a System operating lamp (3) may sometimes light up while the starting switch is turned to "OFF" position
because KOMTRAX terminal (7) may maintain its communication under this condition.
ON/OFF of system operating lamp
• Voltage of 24 V is always applied to one end of the system operating lamp (LED) (3).
• When any of machine monitor (4), controllers (5), (6), and (7) is in operation, the controller outputs low
voltage (0 V), and a current flows in the diode to turn ON system operating lamp (3).
• When all of machine monitor (4), controllers (5), (6), and (7) are stopped, the controller outputs high
voltage (24 V), and no current flows in the diode, thus system operating lamp (3) goes off.
a System operating lamp (3) may look slightly luminous in the dark after it is turned off. It is due to the minute
leakage of current and not an abnormal phenomenon.
• KOMTRAX terminal (7) performs communication periodically even if the starting switch is kept in "OFF"
position, thus it starts and stops repeatedly.
• The start and stop cycle (sleep cycle) of KOMTRAX terminal (7) varies the conditions including the
communication status and machine stop time, and the lamp may keep lighting for up to approximately one
hour
a When you want to cut off the battery circuit for maintenance but system operating lamp (3) keeps on
lighting up, turn the starting switch to "ON" position, and then turn it to "OFF" position, and the lamp goes
off in 2 minutes.
After system operating lamp (3) goes off, turn battery disconnect switch (1) immediately to "OFF" position.
WA320-7 10-209
--- Page 18 ---
10 Structure and function
HST controller system
Fan reverse function (WA320-B715-042-K-00-A)
• When the manual fan reverse mode is operated through the machine monitor to clean the radiator core,
the fan motor EPC solenoid valve of the cooling fan motor operates to reverse the fan rotation.
1. Fan rotation manual reverse function
• The operator can change the fan rotation direction freely by setting the manual fan reverse mode to the
"Reverse" or "Default" position.
• While the fan rotation direction is being changed, the pilot lamp indicating the change is displayed on
the standard screen to notify the operator of the operating condition. If the changing condition is not
satisfied because of high temperature of the coolant or oil, the pilot lamp which indicates that the
satisfaction of the condition is waited lights up.
• On the standard screen, the cooling fan reverse pilot lamp indicates the fan reverse rotation condition.
When all the conditions are satisfied, the fan rotation direction is changed from "Default" to "Reverse".
Condition 1 The manual fan reverse rotation mode is set to "Reverse".
The coolant temperature is below 102°C.
Condition 2
[for prevention of overheat]
The HST oil temperature is below 100°C.
Condition 3
[for prevention of overheat]
The boost temperature is below 119.1°C.
Condition 4
[for prevention of overheat]
At least 5 seconds passed after the fan rotation control at the start of the engine is changed to
Condition 5
the standard control.
Condition 6 There is no error in the fan speed sensor or engine speed sensor.
When any of the conditions is satisfied, the fan rotation direction is changed from "Reverse" to "Default".
The manual fan reverse rotation mode is set to the "Forward" position while the fan is rotating
Condition 1
in reverse.
Condition 2 10 minutes elapse with the fan rotating in reverse.
Condition 3 Abnormality is detected in the fan motor EPC solenoid.
Condition 4 The engine stops.
WA320-7 10-229
--- Page 19 ---
10 Structure and function
HST controller system
1. HST controller
2. Work equipment (boom) control lever
3. Remote boom positioner switch
4. Boom RAISE PPC pressure sensor
5. Boom LOWER PPC pressure sensor
6. Boom potentiometer
7. Boom RAISE detent solenoid
8. Boom LOWER detent solenoid
9. Monitor controller
10. Machine monitor
a. Remote positioner switch signal
b. Boom RAISE PPC pressure signal
c. Boom LOWER PPC pressure signal
d. Boom angle signal
e. CAN signal
f. Work equipment (boom) control lever signal
g. Boom detent solenoid output
Function (WA320-PTL9-042-K-01-A)
Raising kick-out (When pilot lamp lights up to indicate that raising kick-out is effective)
• When the boom lever is set in RAISE detent position, the boom cancels the raising detent and stops
before the set position.
• When the boom is not in the RAISE detent position, it is raised by the operator's operation.
• When RAISE is not selected, the remote positioner does not operate and only the kick-out function
operates (the boom stops at the top).
1. Setting stop position
• The boom stop position when the positioner is operated is changed with the boom positioner switch.
WA320-7 10-249
--- Page 20 ---
10 Structure and function
Machine monitor system
Monitor Function (Action that starts when
Item Display location
display corresponding switch is pressed)
• Service menu "Phone number
entry"
Move between
Moves to right item • Service menu "Testing" o
items (right)
"Cylinder cut-out operation"
Other items (Adjusting screen)
• Service menu "Phone number
entry"
Move between
Moves to left item • Service menu "Testing" o
items (left)
"Cylinder cut-out operation"