PDF Shop Manual Komatsu WB93S-8E0 Backhoe Loader - 25 MB
This is the complete shop manual for the Komatsu WB93S-8E0 Backhoe Loader.
It provides comprehensive, step-by-step procedures for all repair and maintenance tasks.
Technicians will find detailed information on the engine, transmission, hydraulics, and electrical systems.
This manual is the primary resource for troubleshooting and major repairs, ensuring the job is done to factory standards.
PDF Viewer
Viewer loads when you scroll here
SHARE THIS MANUAL
Download the PDF Manual
PDF viewer loading area
Text Preview from This Manual
The text below was extracted from the visible preview pages to help you confirm the manual contents before download.
--- Page 1 ---
WENBM00320
BACKHOE LOADER
WB93S-8E0
SERIAL NUMBERS WB93S-8E0 F25001 and up
--- Page 3 ---
SAFETY NOTICE FOR OPERATION 00 INDEX AND FOREWORD
SAFETY NOTICE FOR OPERATION
• Appropriate servicing and repair are extremely important to ensure safe operation of the machine. The shop
manuals describe the effective and safe servicing and repair methods recommended by Komatsu. Some of
the servicing and repair methods require the use of special tools designed by Komatsu for special purpo-
ses.
• The symbol mark is indicated for such matters that require special precautions. The work indicated with
this warning mark should be performed according to the instructions with special attention. Should a
hazardous situation occurs or be anticipated during such work, be sure to keep safe first and take every
necessary measures.
Safety matters
• Well organized work place
• Correct work clothes
• Observance of work standard
• Enforcement of hand signals
• Prohibition against unlicensed persons operating and handling the machine
• Safety check before starting work
• Wear of dust glasses (for cleaning or grinding work)
• Wear of welding goggles and protectors (for welding work)
• Being in good physical condition, and good preparation
• Always be alert and careful.
General precautions
k If the machine is handled incorrectly, it is dangerous. Read and understand what is described in the
operation and maintenance manual before operation. Read and understand what is described in this
manual before operation.
• Read and understand the meaning of all the safety labels stuck to the machine before performing any
greasing or repairs. For the locations of the safety labels and detailed explanation of precautions, see Oper-
ation and Maintenance Manual.
• Tools and removed parts in the workshop should be well organized. Always keep the tools and parts in their
correct places. Always keep the work area clean and make sure that there is no dust, dirt, oil, or water on
the floor. Smoke only in the designated areas. Never smoke while working.
• Keep all tools in good condition, learn the correct way to use them, and use the proper ones. Check the
tools, machine, forklift truck, service car, etc. thoroughly before starting the work.
• Always wear safety shoes and helmet when performing
any operation. Do not wear loose clothes, or clothes with
buttons missing.
00-16 WB93S-8E0
--- Page 4 ---
00 INDEX AND FOREWORD PRECAUTIONS FOR HANDLING HYDRAULIC EQUIPMENT
REMARK
The oil cleaning equipment can remove the ultra fine (approxi-
mately 3 μm) particles that the filter built in the hydraulic equip-
ment cannot remove. So, it is very effective device.
WB93S-8E0 00-33
--- Page 5 ---
PRECAUTIONS FOR DISCONNECTION AND CONNECTION OF CON-
NECTORS 00 INDEX AND FOREWORD
PRECAUTIONS FOR DISCONNECTION AND CONNECTION OF CONNEC-
TORS
Disconnecting connectors
1. Hold the connectors when disconnecting.
When disconnecting the connectors, always hold the con-
necting portion. If the connector is fixed with screw, loosen
the screw of the connector completely, hold the both of
male and female connectors, and pull them out in parallel.
NOTICE
Do not pull the connectors with one hand.
REMARK
If it is a lock stopper type connector, pull it out as pushing
the stopper (1) with your thumb.
2. When removing a connector from a clip
• Both of the connector and clip have stoppers (2),
which are engaged with each other when the connec-
tor is connected.
• When removing a connector from a clip, pull the con-
nector in parallel with the clip as removing stoppers.
NOTICE
If the connector is pried up and down or to the
right or left, it may break the housing.
3. Action to be taken after removing connectors
After removing the connector, cover it with plastic bags to
prevent entry of dust, dirt, oil, or water in the contact por-
tion.
NOTICE
Be sure to cover the connector with plastic bags when
leaving the machine disassembled for a long time, oth-
erwise defective contact may occur.
Connecting connectors
1. Check the connector visually.
00-50 WB93S-8E0
--- Page 6 ---
00 INDEX AND FOREWORD EXPLANATION OF TERMS FOR MAINTENANCE STANDARD
• The parts whose interferences are out of the allowable interference must be replaced or repaired.
WB93S-8E0 00-67
--- Page 7 ---
CONTENTS 01 SPECIFICATIONS
CONTENTS
SPECIFICATIONS ......................................................................................................................................... 01-3
SPECIFICATION DRAWING................................................................................................................... 01-3
SPECIFICATION DRAWING: WB93S-8E0 ...................................................................................... 01-3
SPECIFICATIONS .................................................................................................................................. 01-5
SPECIFICATIONS: WB93S-8E0 ...................................................................................................... 01-5
WEIGHT TABLE ..................................................................................................................................... 01-6
WEIGHT TABLE: WB93S-8 ............................................................................................................. 01-6
FUEL, COOLANT, LUBRICANTS............................................................................................................ 01-8
USE FUEL, COOLANT AND LUBRICANTS ACCORDING TO AMBIENT TEMPERATURE ............ 01-8
01-2 WB93S-8E0
--- Page 8 ---
10 STRUCTURE AND FUNCTION FUNCTION OF UREA SCR SYSTEM
FUNCTION OF UREA SCR SYSTEM
9
G0160589
1: Engine 6: DOC
2: Engine controller 7: Diesel Particulate filter (DPF)
3: DEF pump 8: Selective catalyst reduction (SCR)
4: DEF tank 9: Clean-up catalyst (CUC)
5: DEF injector
• Urea SCR system is a device which converts toxic nitrogen oxides (NOx) in the exhaust gas into harmless
nitrogen and water.
• By spraying DEF into the exhaust gas, it decomposes and hydrolyzes to form ammonia (NH3) and the am-
monia selectively reacts with nitrogen oxides for the conversion to nitrogen and water.
FUNCTION OF DEF SYSTEM
1: DEF tank
2: DEF suction hose
3: DEF pump
3A: Flow control valve
3B: Pump
3C: DEF filter
3D: Pressure sensor
4: DEF return hose
5: DEF pressure hose
6: DEF injector
• DEF system consists of DEF tank (1), DEF hoses (2), (4),
(5), DEF pump (3), and DEF injector (6).
• The DEF system is a part of the Komatsu Urea SCR sys-
tem and its function is to provide DEF into the SCR Cata-
lyst Assembly.
• However, the comprising devices, such as the DEF pump,
may not start functioning till certain conditions are fulfilled.
• The DEF system has heating systems to thaw and prevent
DEF from freezing because DEF freezes at -11 °C.
WB93S-8E0 10-9
--- Page 9 ---
COMPONENT PARTS OF UREA SCR SYSTEM 10 STRUCTURE AND FUNCTION
DEF TANK HEATING VALVE
STRUCTURE OF DEF TANK HEATING VALVE
A: Engine coolant inlet C: Engine coolant outlet (to DEF tank)
B: Engine coolant outlet (to DEF injector)
1: Solenoid
FUNCTION OF DEF TANK HEATING VALVE
• DEF tank heating valve is a 3-way valve, switching the engine coolant DEF injector or to DEF tank when
DEF tank needs to be thaw DEF tank.
• Switching of the valve is done by solenoid (1).
• The opening position of valve is fixed and the control is only for selecting outlet B or C.
• When the solenoid (1) is de-energized, the valve select outlet B.
• When the solenoid (1) is energized, the valve select outlet C.
10-26 WB93S-8E0
--- Page 10 ---
10 STRUCTURE AND FUNCTION COMPONENT PARTS OF HYDRAULIC SYSTEM
Function of PC valve
• The PC valve limits the oil flow to a certain level (according
to the discharge pressure) even if the stroke of the control
valve is increased extremely so that the horsepower ab- 5
sorbed by the pump does not exceed the engine horse-
power, as long as pump discharge pressure (PA) is high.
• In other words, the PC valve decreases the pump delivery
when the load is increased and the pump dis- charge pres-
sure rises, and increases it when the pump discharge
pressure lowers.
• If pressure PC is increased, the relationship between the
pump pressure (PA) and pump delivery (Q) is translated in
proportion to the pressing force of pressure PC.
• In other words, since the pressing force pressure PC is G0098703
added to the pressing force on the left side caused by the
pump pressure applied to spool (5), the relationship be-
tween pump pressure (PA) and (Q) is translated from [1] to
[2]. 1
Pump delivery Q
2
Pump pressure PA bar
G0098704
OPERATION OF MAIN PUMP SERVO VALVE
Operation of spring
• The spring load of spring (1) at the PC valve is decided by the position of the swash plate.
• If servo piston (2) moves to the right, spring (1) is compressed through lever (3) and its spring load
changes.
WB93S-8E0 10-43
--- Page 11 ---
COMPONENT PARTS OF HYDRAULIC SYSTEM 10 STRUCTURE AND FUNCTION
9: Backhoe boom swing spool 16: Safety valve
10: Backhoe arm spool Set pressure: 21.5 MPa {219 kgf/cm2}
11: Service spool 17: Safety valve
12: Unloading valve: Set pressure: 22.0 MPa {224 kgf/cm2}
Set pressure: LS pressure + 2.75 MPa {28.0 kgf/cm2} 18: Safety valve
13: LS relief valve Set pressure: 34.4 MPa {350 kgf/cm2}
Set pressure: 21.5 MPa {219 kgf/cm2} 19: Pressure compensation valve
14: Safety valve 20: Priority valve
Set pressure: 27.0 MPa {275 kgf/cm2} 21: Servocontrol reducing valve
15: Suction valve 22: Backhoe sliding plate lock solenoid valve
STRUCTURE OF CONTROL VALVE (HYDRAULIC CONTROLS SPECIFICATION)
This topic explains structure of 11-spool loader and backhoe valves.
10-60 WB93S-8E0
--- Page 12 ---
10 STRUCTURE AND FUNCTION COMPONENT PARTS OF HYDRAULIC SYSTEM
WHEN CONTROL VALVE IS IN FINE CONTROL
PP A
1
B S2
S1
S3
2 PLS
T
G0099451
Function
• When the control valve is in the fine control mode, if the demand flow for actuator is less then the value
corresponding to the minimum swash plate angle of the pump, pump pressure PP is set LS pressure PLS +
2.75 MPa {28 kgf/cm2}.
• If the difference pressure between pump pressure PP and LS pressure PLS becomes equal to the load of
spring (2) (2.75 MPa {28 kgf/cm2}), the unload valve opens.
• Accordingly, LS differential pressure ΔPLS is (2.75 MPa {28 kgf/cm2}) at this time.
Operation
• When the control valve is operated finely, LS pressure PLS is generated and applied to area S3 at the right
end of spool (1). At this time difference between LS pressure PLS and pump discharge pressure PP is
large, since the opening area of the control valve spool is narrow.
• When the difference between pump discharge pressure PP and LS pressure PLS reaches the load of
spring (2), spool (1) moves to the right and pump circuit PP and tank circuit T are connected to each other.
• In other words, pump discharge pressure PP is set to a pressure equal to force of spring (2) (2.75 MPa {28
kgf/cm2}) + LS pressure PLS, and differential pressure ΔPLS becomes (2.75 MPa {28 kgf/cm2}) .
WB93S-8E0 10-77
--- Page 13 ---
10-94
PARTS NOT SUPPLIED
BY CARRARO
0.5÷3.5 bar
11 22 ON FWD/RVS CLUTCH POSITION
10
LOCATED IN THE PUMP 9
OPENING 3.5÷5.5 bar t° 0.5÷5,0 bar
ON NEUTRAL CLUTCH POSITION
HOSE HOSE
2: Transmission pump
3 TEETH REMOVED ON
3: Spin-on filter (10 μm)
8
1: Suction filter (250 μm)
TORQUE CONVERTER
(~10 mm 2)
TRANSMISSION CONTROL VALVE UNIT
11÷13.0 bar BEARING
29 13 24
21
16
HYDRAULIC CIRCUIT DIAGRAM
15
14
0.5÷9.0 bar FWD
COMPONENT PARTS OF POWER TRAIN SYSTEM
2nd GEAR
REV
28 1st GEAR
4
12 23
REAR AXLE 20
UNIT 17
11÷13.0 bar
4th GEAR
25
11÷13.0 bar
5: Oil relief valve
900 rpm 13.0÷14.0 bar BY-PASS
2200 rpm 13.0÷15.5 bar 3 3rd GEAR
OPENS AT
4: Pressure regulator
6 3.45 BAR
26 27
5 2
BEARING
LOCATED
4WD IN THE PUMP
OPENS AT 23 bar AIR
BREATHER 19
7
18
1
6: 4WD disengagement solenoid valve
TRANSMISSION SUMP
G0136191
WB93S-8E0
10 STRUCTURE AND FUNCTION
--- Page 14 ---
10 STRUCTURE AND FUNCTION COMPONENT PARTS OF POWER TRAIN SYSTEM
PINION AND DIFFERENTIAL
C
B B
C
1 2 3
4
5 C-C
6
11
10
9
7
8
B-B G0103671
1: Ring nut 7: Bearing
2: Sun gear 8: Differential support
3: Differential housing 9: Crown wheel
4: Pinion 10: Pin
5: Spacer 11: Planetary gear
6: Ring nut
Specification
Axle oil quantity: 10.5 ℓ
WB93S-8E0 10-111
--- Page 15 ---
LOADER WORK EQUIPMENT PPC VALVE 10 STRUCTURE AND FUNCTION
Sectional view
6
5 7
4 8
3
9
2
10
1
A-A 11 C-C
D-D
B-B G0099475
1: Spool 7: Joint
2: Centering spring 8: Cover
3: Metering spring 9: Retainer
4: Piston 10: Piston
5: Disk 11: Valve body
6: Disk
10-128 WB93S-8E0
--- Page 16 ---
10 STRUCTURE AND FUNCTION SOLENOID VALVES
SOLENOID VALVES
SOLENOID VALVE GROUP (HYDRAULIC CONTROLS SPECIFICATION)
STRUCTURE
ACC P1
A2 HC UBH 6
7
P2 UL P
A
T
PM
1 2 3 4 5
Hydraulic circuit
ACC A2 PM HC UBH UL B1 A1
A1 P1
233 233 233 233 0.5mm
P2
B1
P T
View A
G0099647
1: Boom unlock solenoid valve (F03) 5: PPC solenoid valve (F01)
2: Power mode solenoid valve (F08) 6: Loader bucket 4 in 1 solenoid valve (OPEN) (F10)
3: Backhoe hammer solenoid valve (F05) 7: Loader bucket 4 in 1 solenoid valve (CLOSE) (F11)
4: Backhoe PPC solenoid valve (F02)
WB93S-8E0 10-145
--- Page 17 ---
CONTENTS 20 STANDARD VALUE TABLE
CONTENTS
STANDARD VALUE TABLE FOR ENGINE .................................................................................................... 20-3
STANDARD VALUE TABLE FOR ENGINE: WB93S-8E0 ........................................................................ 20-3
STANDARD VALUE TABLE FOR MACHINE.................................................................................................. 20-6
STANDARD VALUE TABLE FOR MACHINE: WB93S-8E0 ..................................................................... 20-6
MACHINE POSTURE AND PROCEDURES TO MEASURE PERFORMANCE .................................... 20-26
20-2 WB93S-8E0
--- Page 18 ---
20 STANDARD VALUE TABLE STANDARD VALUE TABLE FOR MACHINE: WB93S-8E0
Standard value for
Item Test condition Unit Repair limit
new machine
• For details about measurement posi-
tion, see fig. 7 of “MACHINE POS-
TURE AND PROCEDURES TO
MEASURE PERFORMANCE
(20-26)”."
• Hydraulic oil temperature: 45 to 55 °C
• With standard arm: add 410 to bucket
Backhoe arm • With telescopic arm: fully extend arm Max. 10 Max. 20
cylinder retrac- and do not add weight to bucket mm
tion amount [Max. 14] [Max. 28]
• Bucket weight: 155 kg
• Engine: stopped [*1]
• Measure immediately after setting
• Measure hydraulic drift every 5 minutes
and judge after 15 minutes
[ ]: value for machine equipped with cold cli-
mate device
• For details about measurement posi-
tion, see fig. 7 of “MACHINE POS-
TURE AND PROCEDURES TO
MEASURE PERFORMANCE
(20-26)”."
• Hydraulic oil temperature: 45 to 55 °C