988F and 988F II Wheel Loader Hydraulic System: Machine Component and Tap Locations
988F and 988F II Wheel Loader Hydraulic System: Machine Component and Tap Locations
988F and 988F II Wheel Loader Hydraulic System: Machine Component and Tap Locations
August 2012
Component Location FLUID POWER SYMBOLS
Machine Schematic
22 Description Part Number
Location Location
BASIC COMPONENT SYMBOLS
988F 988F II
35
MAIN AUX
12 26 Accumulator (Ride Control Att.) NOT USED 6E-6400 1 D-1 PUMP OR MOTOR FLUID CONDITIONER SPRING CONTROL VALVES RESTRICTION LINE RESTRICTION
(FIXED)
PUMP
(2 - SECTION)
PUMP
(VARIABLE & PRESSURE
41 30 47
VARIABILITY SPRING LINE RESTRICTION PRESSURE HYDRAULIC PNEUMATIC LINE RESTRICTION ATTACHMENT
13 32 18 42 27 23 A D 34 Cylinder Gp - Steering 9J-8165 9J-8165 5 D-8 , D-9 (ADJUSTABLE) (VARIABLE) COMPENSATION ENERGY TRIANGLES (VARIABLE & PRESSURE
COMPENSATED)
16
D-4
D-6
988F and 988F II Wheel Loader MEASUREMENT ROTATING SHAFTS
Pump Gp - Fan Drive Pump (Standard) 6E-1229 6E-1229
Pump Gp - Hand Metering (Steering)
Pump Gp - Implement (Logger)
6E-2726
6E-5853
119-8763
6E-5853
17 B-9 Hydraulic System PRESSURE TEMPERATURE FLOW UNIDIRECTIONAL BIDIRECTIONAL
18 B-4
Pump Gp - Implement (Standard) 109-3420 143-8688
Pump Gp - Steering (Brake And Pilot) 109-3421 145-3996 19 B-7
988F: 988F II: COMBINATION CONTROLS
Tap Location
Pressure and Sampling
Tap Schematic
Description
Number Location
A Steering System D-8 , D-9 PRESSURE SWITCH PRESSURE SWITCH TEMPERATURE ELECTRICAL WIRE
G (ADJUSTABLE) SWITCH
UENR3655
B Brake System C-6
C Pilot Pressure B-6
D Implement Relief Pressure C-3
E Tilt Head End Pressure D-2 ELECTRICAL SYMBOLS (ELECTRICAL)
F Tilt Rod End Pressure D-2
26
G Accumulator Pressure C-5
C
ELECTRICAL SCHEMATIC EXAMPLE HYDRAULIC SCHEMATIC EXAMPLE
CURRENT STANDARD CURRENT STANDARD
VIEW A 27
HARNESS IDENTIFICATION CODE THIS EXAMPLE
INDICATES WIRE 135 IN HARNESS “AG”
WIRE
20 Page,
CIRCUIT NUMBER
325-AG135 PK-14 IDENTIFICATION WIRE COLOR
PREVIOUS STANDARD
PILOT VALVE
9 8 7 6 5 4 3 2 1
RIGHT RIGHT
TURN TURN
STEERING STEERING
CYLINDERS CYLINDERS (38) VALVE GP
OIL COOLER BYPASS (41) VALVE GP (40) VALVE GP
6E-1129 (12) MOTOR GP
FAN DRIVE MOTOR PILOT (TILT, LIFT AND AUX) PILOT (TILT AND LIFT)
(53) VALVE GP (STANDARD) - 6E-1141 111-1529 111-1528
RELIEF (HIGH AMBIENT) - 110-6351
118-4297
(6) CYLINDER GP
E (13) OIL COOLER TILT
(46) VALVE GP 132-5259 (988F II) (STANDARD) - 9J-3632
(46) VALVE GP STEERING CONTROL 4P-4710 (988F) (LOGGER) - 3G-2976
STEERING CONTROL 139-5270 (988F II) (39) VALVE GP (HIGH LIFT) - 4T-6792
8J-2318 6E-4031 (988F) PARKING BRAKE CONTROL (4) CYLINDER GP
(16) PUMP GP (32) VALVE GP 100-8941 (3) CYLINDER GP LIFT
D FAN DRIVE PUMP FAN DRIVE MAKE-UP D
AUXILIARY 9T-8257 (31) VALVE GP
(STANDARD) - 6E-1229 (STANDARD) - 105-2470 DIVERTER
(HIGH AMBIENT) - 6E-6425 (HIGH AMBIENT) - 110-5270 (RIDE CONTROL ATT.)
124-5752
(7) FILTER GP
F
LOWER/CLOSE
DUMP
LOWER
(15) PARKING BRAKE
VENT
RAISE/OPEN
RAISE
RACK BACK
FAN DRIVE OIL (22) SWITCH AS
4T-4284 LOW BRAKE OIL PRESSURE (1) ACCUMULATOR
(RIDE CONTROL ATT.)
A 174-4312 (988F II)
6E-6400
C (2) ACCUMULATOR GP
3E-6452 (988F) AUX TILT LIFT
C
BRAKE OIL
A D C (14) ORIFICE
E 7I-3032, 127-5801(For Stick Steer) 100-6909 PARKING
BRAKE (26) VALVE GP E
4E-0110 PRESSURE BRAKE CONTROL
9J-4080
D (27) VALVE GP B (23) SWITCH AS
BRAKE OIL PARKING BRAKE
(35) VALVE GP ACCUMULATOR CHARGING 171-7085 (988F II)
LEFT STEERING 9J-4693 (25) SWITCH AS 3E-6452 (988F) H.E. ACU
(35) VALVE GP (43) VALVE GP LEFT RIGHT R.E. T
NEUTRALIZER TRANSMISSION (21) SERVICE BRAKES
LEFT STEERING RIGHT STEERING 9T-7426 NEUTRALIZER
NEUTRALIZER NEUTRALIZER (43) VALVE GP 4E-8950
8J-1553 8J-1553 (48) VALVE GP RIGHT STEERING
STEERING PILOT
RIGHT
CONTROL
NEUTRALIZER
9T-7426
G SERVICE
BRAKE
LEFT
PRESSURE
143-2855 (988F II)
C 6E-3182 (988F) C
LOWER/CLOSE
RAISE/OPEN
RACK BACK
LOWER
RAISE
DUMP
STEER
(17) PUMP GP D
HAND METERING (47) VALVE GP
(STEERING) STEERING DUAL
119-8763 (988F II) CHECK (21) SERVICE BRAKES
6E-2726 (988F) 111-7775 (988F II)
6E-3723 (988F) T R.E. H.E. H.E.
(9) FILTER GP P H.E.
T
P R.E
T
P R.E
6P-4603
(37) VALVE GP
(28) VALVE GP IMP PILOT VALVE RETURN LIFT CYLINDER
C CHECK (45) VALVE GP ROD END CHECK
9T-3096
(Dimensions: 39 inches x 24 inches)
104-7108 SELECTOR
(30) VALVE GP
B CHECK
B 6E-5566
LIFT CYL PRESSURE
(52) VALVE GP (36) VALVE GP
104-7108 (51) VALVE GP (50) VALVE GP
MAIN RELIIEF LIFT CYLINDER
(30) VALVE GP (42) VALVE GP (STANDARD) - 6E-2920 CONTROL (TILT, LIFT AND AUX) CONTROL (TILT AND LIFT)
PILOT SYSTEM RELIEF HEAD END CHECK
CHECK (LOGGER) - 3G-3460 9T-1483 9T-1484
6E-6178 9T-3096
(44) VALVE GP 9T-3096 (988F II)
SELECTOR 9T-4543 (988F) IMPL PILOT SUPPLY
A
UENR3655
B A B
6E-5566
(33) VALVE GP IMPL RETURN
FLUID SAMPLE (34) VALVE GP
D 8C-3446 HYDRAULIC TANK RELIEF
9T-0818
(18) PUMP GP
TO LIGHT A B IMPLEMENT
ON DASH IMPL CASE DRAIN
(STANDARD) - 109-3420 (988F) , 143-8688 (988F)
(LOGGER) - 6E-5853
(10) HYDRAULIC TANK (11) JUNCTION BLOCK
(19) PUMP GP 2V-7777
(24) SWITCH AS STEERING (BRAKE AND PILOT) 9T-4971 LINE PATTERNS
SUPPLIMENTAL STEERING FLOW 145-3996 (988F II) (8) FILTER GP
3E-6429 (988F II) MAIN OIL Pressure Line
109-3421 (988F)
9X-0008 (988F) IMPL PUMP SUPPLY Pilot / Load Sensing Pressure
9 8 7 6 5 4 3 2 1