cat 988F and 988F II Wheel Loader Hydraulic System Schematic Manual - PDF DOWNLOAD

SENR5736-03 July 2012

FLUID POWER SYMBOLS

Component Location

22

42

25 27

39 23

A

34

D

43

37

41 30 47 28

52

40

33

988F II 6E-6400

1

D-1

Accumulator Gp - Brake Oil

100-6909

100-6909

2

C-6

45 17

F

50

E

51 1 36 31

48

6

Cylinder Gp - Auxiliary

NOTE A

NOTE A

3

D-2

Cylinder Gp - Lift

9T-8257

9T-8257

4

D-1

Cylinder Gp - Steering

9J-8165

9J-8165

5

D-8 , D-9

6

D-2

Cylinder Gp - Tilt (High Lift)

4T-6792

4T-6792

Cylinder Gp - Tilt (Logger)

3G-2976

3G-2976

Cylinder Gp - Tilt (Standard)

9J-3632

9J-3632

Filter Gp - Fan Drive Oil

4T-4284

4T-4284

7

D-6

Filter Gp - Main Oil

NOTE A

NOTE A

8

B-6

Filter Gp - Pilot System Oil

6P-4603

6P-4603

9

B-6

Hydraulic Tank

9T-4971

9T-4971

10

B-6

Junction Block

2V-7777

2V-7777

11

B-6

-

110-6351

Motor Gp - Fan Drive Motor (Standard)

6E-1141

6E-1141

Oil Cooler

4P-4710

4P-4710

Motor Gp - Fan Drive Motor (High Ambient)

Orifice

4.00E-110

7I-3032

-

127-5801

-

-

Pump Gp - Fan Drive Pump (High Ambient)

6E-6425

6E-6425

Pump Gp - Fan Drive Pump (Standard)

6E-1229

6E-1229

Parking Brake

49 46 14 38

D-6

13

D-7

14

D-7

15

D-4

16

D-6

17

B-9

18

B-4

19

B-7

6E-2726

6E-2726

Pump Gp - Implement (Logger)

6E-5853

6E-5853

Pump Gp - Implement (Standard)

6E-3718

109-3420

Pump Gp - Steering (Brake And Pilot)

6E-3719

109-3421

Pump Gp - Supplimental Steering

3G-6856

3G-6856

20

B-9

-

-

21

C-5

Switch As - Low Brake Oil Pressure Switch

3E-6452

174-4312

22

D-6

Switch As - Parking Brake

3E-6452

171-7085

23

C-4

Switch As - Supplemental Steering Flow

9X-0008

9X-0008

24

B-6

Switch As - Transmission Neutralizer

4E-8950

4E-8950

25

C-5

Valve Gp - Brake Control

9J-4080

9J-4080

26

C-5

Valve Gp - Brake Oil Accumulator Charging

9J-4693

9J-4693

27

C-6

Valve Gp - Check

104-7108

104-7108

28

B-6

Valve Gp - Check

9T-4543

9T-4543

29

B-7

Valve Gp - Check

8

12

Pump Gp - Hand Metering (Steering)

Service Brakes

20

MAIN

104-7108

104-7108

30

B-8

Valve GP - Diverter (Ride Control Att.)

NOT USED

124-5752

31

C-1

Valve Gp - Fan Drive Make-Up (High Ambient)

NOT USED

110-5270

32

D-6

Valve Gp - Fan Drive Make-Up (Standard)

105-2470

105-2470

Valve Gp - Fluid Sample

8C-3446

8C-3446

33

B-6

Valve Gp - Hydraulic Tank Relief

9T-0818

9T-0818

34

B-6

Stick Steer

9T-7426

9T-7426

35

C-8

21

2

53

5

24 10 44 29 11

4

Wheel Steer

8J-1553

8J-1553

35

C-9

SPRING

CONTROL VALVES

VARIABILITY

SPRING (ADJUSTABLE)

LINE RESTRICTION (VARIABLE)

PRESSURE COMPENSATION

ONE POSITION

Valve Gp - Lift Cylinder Head End Check

9T-3096

9T-3096

36

B-1

Valve Gp - Lift Cylinder Rod End Check

9T-3096

9T-3096

37

C-1

Valve Gp - Oil Cooler Bypass

6E-1129

6E-1129

38

D-7

Valve Gp - Parking Brake Control

100-8941

100-8941

39

D-5

Valve Gp - Pilot (Tilt and Lift)

108-6262

111-1528

40

D-3

Valve Gp - Pilot (Tilt, Lift and Aux)

108-6263

111-1529

41

D-3

Valve Gp - Pilot System Relief

6E-6178

6E-6178

42

B-6

9T-7426

9T-7426

43

C-7

RESTRICTION

LINE RESTRICTION (FIXED)

PUMP (VARIABLE & PRESSURE COMPENSATED)

LINE RESTRICTION (VARIABLE & PRESSURE COMPENSATED)

HYDRAULIC PNEUMATIC ENERGY TRIANGLES

ATTACHMENT

VALVE PORTS

THREE POSITION

TWO - WAY

THREE - WAY

CONTROL VALVES AB

PUMP (2 - SECTION)

VALVES

TWO POSITION

FOUR - WAY

CHECK VALVES

A B

P T

P T

NORMAL POSITION

SHIFTED POSITION

BASIC SYMBOL

INFINITE POSITION

SHUTTLE

SPRING LOADED

PILOT CONTROLLED

FLUID STORAGE RESERVOIRS

988F and 988F II Wheel Loader Hydraulic System 988F: 8YG1-209

PRESSURIZED

VENTED

RETURN ABOVE FLUID LEVEL

RETURN BELOW FLUID LEVEL

MEASUREMENT

PRESSURE

ROTATING SHAFTS

TEMPERATURE

UNIDIRECTIONAL

FLOW

988F II: 2ZR1-699

BIDIRECTIONAL

COMBINATION CONTROLS

SOLENOID

SOLENOID OR MANUAL

SOLENOID & PILOT

SOLENOID & PILOT OR MANUAL

SERVO

THERMAL

DETENT

MANUAL CONTROL SYMBOLS

MANUAL SHUTOFF

PUSH - PULL LEVER

GENERAL MANUAL

EXTERNAL RETURN

INTERNAL RETURN

PEDAL

GAS CHARGED

SIMPLIFIED

LINES CROSSING

COMPLETE

VARIABLE DISPLACEMENT NON-COMPENSATED

FIXED DISPLACEMENT

SINGLE ACTING

LINES JOINING

UNIDIRECTIONAL

BIDIRECTIONAL

BIDIRECTIONAL

DOUBLE ACTING

INTERNAL PASSAGEWAYS

VARIABLE DISPLACEMENT NON-COMPENSATED

UNIDIRECTIONAL

INTERNAL SUPPLY PRESSURE

HYDRAULIC & PNEUMATIC CYLINDERS

HYDRAULIC MOTORS

HYDRAULIC PUMPS

SPRING

REMOTE SUPPLY PRESSURE

CROSSING & JOINING LINES

ACCUMULATORS

FIXED DISPLACEMENT

PUSH BUTTON

PILOT CONTROL SYMBOLS

RELEASED PRESSURE

SPRING LOADED

21

MACHINE COMPONENT AND TAP LOCATIONS

FLUID CONDITIONER

VALVE ENVELOPES

Valve Gp - Left Steering Neutralizer

7

PUMP OR MOTOR

AUX

INFINITE POSITIONING

3 POSITION

FLOW IN ONE DIRECTION

PARALLEL FLOW

CROSS FLOW

2 POSITION

FLOW IN EITHER DIRECTION

Valve Gp - Right Steering Neutralizer Stick Steer

8J-1553

8J-1553

43

C-9

Valve Gp - Selector

Wheel Steer

6E-5566

6E-5566

44

B-8

Valve Gp - Selector

6E-5566

6E-5566

45

B-5

Stick Steer

6E-4031

128-5347

46

D-8

Wheel Steer

8J-2318

8J-2318

46

D-9

Valve Gp - Steering Dual Check

6E-3723

6E-3723

47

C-7 C-8

© 2012 Caterpillar, All Rights Reserved

Printed in U.S.A.

Valve Gp - Steering Control

Valve Gp - Steering Pilot Control

6E-3182

6E-3182

48

Valve Gp - Supplimental Steering Diverter

8J-6099

8J-6099

49

A-9

Valve Gp -Control (Tilt and Lift)

9T-1484

9T-1484

50

C-2

51

C-2

52

C-3

53

D-7

Valve Gp -Control (Tilt, Lift and Aux)

9T-1483

9T-1483

Valve Gp -Main Relief (Logger)

3G-3460

3G-3460

Valve Gp -Main Relief (Standard)

6E-2920

6E-2920

NOT USED

118-4297

Valve Gp - Relief

ELECTRICAL SYMBOLS TABLE HYDRAULIC SYMBOLS (ELECTRICAL)

G

M

Note A: Refer to the Parts Manual for your specific machine.

TRANSDUCER (FLUID)

TRANSDUCER (GAS / AIR)

GENERATOR

ELECTRIC MOTOR

PRESSURE SWITCH

PRESSURE SWITCH (ADJUSTABLE)

TEMPERATURE SWITCH

ELECTRICAL WIRE

Tap Location Pressure and Sampling Tap Number

Description

Schematic Location

A

Steering System

B

Brake System

D-8 , D-9 C-6

C

Pilot Pressure

B-6

D

Implement Relief Pressure

C-3

E

Tilt Head End Pressure

D-2

F

Tilt Rod End Pressure

D-2

G

Accumulator Pressure

C-5

G

26

ELECTRICAL SYMBOLS (ELECTRICAL)

T

PRESSURE SWITCH

TEMPERATURE SWITCH

LEVEL SWITCH

FLOW SWITCH

A WIRE NUMBER IDENTIFICATION CODES

C

27

VIEW A

ELECTRICAL SCHEMATIC EXAMPLE

HYDRAULIC SCHEMATIC EXAMPLE

CURRENT STANDARD

CURRENT STANDARD

HARNESS IDENTIFICATION CODE THIS EXAMPLE INDICATES WIRE 135 IN HARNESS “AG” WIRE CIRCUIT NUMBER IDENTIFICATION

325-AG135 PK-14

B

CIRCUIT NUMBER IDENTIFICATION

WIRE COLOR

WIRE COLOR

WIRE GAUGE

325-PK

PREVIOUS STANDARD WIRE

VIEW B

SERVICE BRAKE

PILOT VALVE

B

325-PK-14

CIRCUIT NUMBER IDENTIFICATION

B

WIRE COLOR

WIRE GAUGE

A

(EXAMPLE VALVE)

(Dimensions: 39 inches x 24 inches)

18

32

9

988F NOT USED

Accumulator (Ride Control Att.)

BASIC COMPONENT SYMBOLS

20 Page,

19

16 13

35

26

Schematic Location

SENR5736-03

12

Part Number

Description

Machine Location

9

8

7

WHEEL STEER

6

5

4

3

2

1

STICK STEER

E

E

(5) CYLINDER GP STEERING 9J-8165

(5) CYLINDER GP STEERING 9J-8165

(12) MOTOR GP FAN DRIVE MOTOR (STANDARD) - 6E1141 (HIGH AMBIENT) - 110-6351

E

D

C

E

D

(35) VALVE GP LEFT STEERING NEUTRALIZER 8J-1553

(43) VALVE GP RIGHT STEERING NEUTRALIZER 8J-1553

(27) VALVE GP BRAKE OIL ACCUMULATOR CHARGING 9J-4693 LEFT

C

PARKING BRAKE PRESSURE

B

(25) SWITCH AS TRANSMISSION NEUTRALIZER 4E-8950

(43) VALVE GP RIGHT STEERING NEUTRALIZER 9T-7426

G

VENT

LOWER

H.E. R.E.

(21) SERVICE BRAKES

D

(Dimensions: 39 inches x 24 inches)

20 Page,

SENR5736-03

(28) VALVE GP CHECK 104-7108

C

A

B

(44) VALVE GP SELECTOR 6E-5566

A

R.E. H.E. T

T P P

H.E. R.E T

T P P

H.E. R.E T

IMP PILOT VALVE RETURN

(45) VALVE GP SELECTOR 6E-5566

LIFT CYL PRESSURE

(52) VALVE GP MAIN RELIIEF (STANDARD) - 6E-2920 (LOGGER) - 3G-3460

(51) VALVE GP CONTROL (TILT, LIFT AND AUX) 9T-1483

(50) VALVE GP CONTROL (TILT AND LIFT) 9T-1484

(36) VALVE GP LIFT CYLINDER HEAD END CHECK 9T-3096

IMPL PILOT SUPPLY

B

D

A

IMPL RETURN

(34) VALVE GP HYDRAULIC TANK RELIEF 9T-0818

(18) PUMP GP IMPLEMENT (STANDARD) - 109-3420(988F II) , 6E-3718(988F) (LOGGER) - 6E-5853

B IMPL CASE DRAIN

ON DASH

(24) SWITCH AS SUPPLIMENTAL STEERING FLOW 9X-0008

C

(37) VALVE GP LIFT CYLINDER ROD END CHECK 9T-3096

(42) VALVE GP PILOT SYSTEM RELIEF 6E-6178

(33) VALVE GP FLUID SAMPLE 8C-3446

TO LIGHT

T P P

Parking and Service Brake

B (29) VALVE GP CHECK 9T-4543

ACU T

(21) SERVICE BRAKES (9) FILTER GP PILOT SYSTEM OIL 6P-4603

(30) VALVE GP CHECK 104-7108

LIFT

SERVICE BRAKE PRESSURE

(47) VALVE GP STEERING DUAL CHECK 6E-3723

B

TILT

(1) ACCUMULATOR (RIDE CONTROL ATT.) 6E-6400

(23) SWITCH AS PARKING BRAKE 171-7085 (988F II) 3E-6452 (988F)

STEER

(17) PUMP GP HAND METERING (STEERING) 6E-2726

(10) HYDRAULIC TANK 9T-4971

(19) PUMP GP STEERING (BRAKE AND PILOT) 109-3421 (988F II) 6E-3719 (988F)

(11) JUNCTION BLOCK 2V-7777

LINE PATTERNS

(8) FILTER GP MAIN OIL

Pressure Line

IMPL PUMP SUPPLY

Pilot / Load Sensing Pressure Drain / Return Lines

(20) PUMP GP SUPPLIMENTAL STEERING 3G-6856

Component Group Attachment

(49) PUMP GP SUPPLIMENTAL STEERING DIVERTER 8J-6099

Air Line

A

CALLOUTS Taps (Pressure, Sampling, Sensor - by letter)

YY

HYDRAULIC CIRCUIT COLOR DESCRIPTIONS PILOT CIRCUIT IMPLEMENTS PUMPS SUPPLIMENTAL STEERING PUMP TILT CYLINDERS STEERING CIRCUIT SUPPLY LINE PARKING AND SERVICE BRAKE DRAIN / RETURN LINE LIFT CYLINDER AUX CYLINDERS

988F II ONLY 9

D

E

(26) VALVE GP BRAKE CONTROL 9J-4080

RIGHT

(48) VALVE GP STEERING PILOT CONTROL 6E-3182

RIGHT

LEFT

(35) VALVE GP LEFT STEERING NEUTRALIZER 9T-7426

4E-0110

AUX

RACK BACK

A

(2) ACCUMULATOR GP BRAKE OIL (14) ORIFICE 100-6909 7I-3032, 127-5801(For 988F II Only)

RAISE/OPEN

C

(31) VALVE GP DIVERTER (RIDE CONTROL ATT.) 124-5752

F

LOWER/CLOSE

A

C

(15) PARKING BRAKE

(22) SWITCH AS LOW BRAKE OIL PRESSURE 174-4312 (988F II) 3E-6452 (988F)

DUMP

(7) FILTER GP FAN DRIVE OIL 4T-4284

(4) CYLINDER GP LIFT 9T-8257

(3) CYLINDER GP AUXILIARY

RAISE

(32) VALVE GP FAN DRIVE MAKE-UP (STANDARD) - 105-2470 (HIGH AMBIENT) - 110-5270

RACK BACK

(16) PUMP GP FAN DRIVE PUMP (STANDARD) - 6E1229 (HIGH AMBIENT) - 6E-6425

D

(39) VALVE GP PARKING BRAKE CONTROL 100-8941

LOWER/CLOSE

(46) VALVE GP STEERING CONTROL 128-5347 (988F II) 6E-4031 (988F)

(46) VALVE GP STEERING CONTROL 8J-2318

(6) CYLINDER GP TILT (STANDARD) - 9J-3632 (LOGGER) - 3G-2976 (HIGH LIFT) - 4T-6792

(13) OIL COOLER 4P-4710

LOWER

(53) VALVE GP RELIEF 118-4297

(40) VALVE GP PILOT (TILT AND LIFT) 111-1528 (998F II) 108-6262 (988F)

(41) VALVE GP PILOT (TILT, LIFT AND AUX) 111-1529 (988F II) 108-6263 (988F)

RAISE

(38) VALVE GP OIL COOLER BYPASS 6E-1129

DUMP

RIGHT TURN STEERING CYLINDERS

RAISE/OPEN

RIGHT TURN STEERING CYLINDERS

8

7

6

5

4

3

THIS SCHEMATIC IS FOR THE 988F AND 988F II WHEEL LOADER HYDRAULIC SYSTEM MEDIA NUMBER: SENR5736-03 SCHEMATIC PART NUMBER: 6E-5381, CHANGE: 00, VERSION: SCHEMATIC PART NUMBER: 128-5712, CHANGE: 00, VERSION: Components are shown installed on a fully operable machine with the key and engine off, transmission shifter in neutral and with parking brake set.

Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.

2

1

A