RENR6506-00

30Page,B/W,D.G.M.

©2003 Caterpillar

All Rights Reserved

Printed in U.S.A.

RENR6506-00July 2003

773 and 775E Off-Highway TruckHydraulic System

BDA259-UPBEC202-UP

ONE POSITION TWO POSITION THREE POSITION

VENTED PRESSURIZED RETURN ABOVE FLUID LEVEL RETURN BELOW FLUID LEVEL

LINES CROSSING LINES JOINING

TWO-WAY THREE-WAY FOUR-WAY

SPRING CONTROL VALVES RESTRICTION LINE RESTRICTION

(FIXED)

2-SECTION PUMP

MAIN AUX.

SPRING

(ADJUSTABLE)

VARIABLILTY LINE RESTRICTION

(VARIABLE)

LINE RESTRICTION(VARIABLE and PRESSURE COMPENSATED)

PRESSURE

COMPENSATION

PUMP: VARIABLE andPRESSURE COMPENSATED

ENERGY TRIANGLES

HYDRAULIC PNEUMATIC

MEASUREMENT

PRESSURE TEMPERATURE FLOW

ROTATING SHAFTS

UNIDIRECTIONAL BIDIRECTIONAL

PUSH-PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING

MANUAL CONTROL SYMBOLS

HYDRAULIC MOTORS

FIXED

DISPLACEMENT

VARIABLE DISPLACEMENT

NON-COMPENSATED

UNIDIRECTIONAL

BIDIRECTIONAL

HYDRAULIC PUMPS

FLUID STORAGE RESERVOIRS

CROSSING AND JOINING LINES

VALVE ENVELOPES VALVE PORTS

BASIC COMPONENT SYMBOLS

FLUID CONDITIONERPUMP or MOTOR

FLUID POWER SYMBOLS

FIXED

DISPLACEMENT

VARIABLE DISPLACEMENT

NON-COMPENSATED

UNIDIRECTIONAL

BIDIRECTIONAL

VALVES

PILOT CONTROL SYMBOLSRELEASED PRESSURE

EXTERNAL RETURN INTERNAL RETURN

REMOTE SUPPLY PRESSURE

SIMPLIFIED COMPLETE INTERNAL

SUPPLY PRESSURE

ACCUMULATORS

SPRING LOADED GAS CHARGED

SOLENOIDor MANUAL

SOLENOIDand PILOT

SOLENOID andPILOT or MANUAL

COMBINATION CONTROLS

SOLENOID SERVO THERMAL DETENT

HYDRAULIC AND PNEUMATIC CYLINDERS

DOUBLE ACTINGSINGLE ACTING

BASIC SYMBOL SPRING LOADED

CHECK VALVES

TWO

POSITION

INFINITE

POSITIONING

FLOW IN ONE

DIRECTION

FLOW ALLOWED IN

EITHER DIRECTION

THREE

POSITION

CROSS

FLOWPARALLEL

FLOW

INTERNAL PASSAGEWAYS

NORMAL POSITION

A B

P T

A B

P T

SHIFTED POSITION INFINITE POSITION

CONTROL VALVES

Hoist Control Valve Main Pump

Steering Check and Relief Valve (43)

52G704-YLE790-PK 11

43

1015

704-GY922-BR

703-BU922-BR

G705-GNE790-PK

54

Pump and Motor for the Secondary Steering, Brake Release,Prelubrication, and QuickEvac

Transmission Hydraulic Control (58) Transmission Rear View

22 3123

UpshiftSolenoid

705-PK922-BR

Lockup ClutchSolenoid

DownshiftSolenoid

Traction Control Valve

Parking and Secondary Brake Valve (47)

Diverter Valve (Towing) (40)

Selector Solenoid(4 Way)

40

47

774-YLK952-BR775-BRK952-BR

773-GYK952-BR

ProportionalSolenoidValve

ItemPart

NumberDescription

Schematic

LocationItem

Part

NumberDescription

Schematic

Location

1 2A-7070 Service and Parking Brake (Rear)F-3, I-3

D-12 , I-1232 138-4733

Check Valve

(Parking Brake Release)H-10 / H-2

2 9C-4937Air Breather

(Torque Converter and Transmission)B-10 33 123-5150 Check Valve B-7

3 145-5155 Hoist Cylinder D-8 35 104-1817 Oil Cooler (Power Train) C-12

4 8X-3572 Plate (Orifice) D-8 36 9T-5665 Hydraulic Filter (Steering) G-3

5 8P-3795 Screen A-11 37 8X-6987 Air/Hydraulic Cylinder (Front Brake) H-7

6 9P-0673 Relief Valve (Torque Converter Inlet) A-10 38 170-8018 Hydraulic Tank (Steering) B-3

7 111-6841 Transmission Charging Pump Section A-12 39 9T-0818 Steering Pump Case Drain Filter B-3

8 111-6841 Transmission Scavenge Pump Section A-12 40 3G-2887 Diverter Valve (Towing) G-10

9 8P-3795 Screen A-13 41 8X-4575 Air Breather (Hoist and Brake) E-9

10 111-8399 Brake Pump Section G-8 / H-1 42 9P-0673 Air/Hydraulic Cylinder (Rear Brake) G-12

11 111-8399 Hoist Pump Section G-8 43 Check and Relief Valve (Steering) D-2

12 105-3357 Steering Cylinder F-2 44Relief Valve

(Primary Steering Backup)D-2

13 8W-7374 Hydraulic Caliper Service Brake (Front) F-5 / H-5 45Relief Valve

(Secondary Steering Backup)D-2

14 192-4286 Metering Pump (Steering) E-2 46 Pressure Reducing Valve (Steering) D-3

15 219-1964 Piston Pump (Steering) G-8 / C-2 47 113-1543 Brake Valve (Parking and Secondary) H-10

16 219-1964 Pressure Compensator Valve C-2 48 153-2739 Hydraulic Tank (Hoist and Brake) D-9 / D-10

17 212-0394Lockup Clutch and Solenoid Valve

(Torque Converter)B-12 49 9T-9227 Screen D-9

18 132-5447 Hydraulic Filter (Power Train) B-11 50 7J-3723 Screen D-9

19 132-5448 Hydraulic Filter (Parking Brake Release) G-8 / H-2 51 Control Valve (Hoist) E-6

20 8J-6875 Shuttle Valve (Resolver Valve – Steering) D-2 52Proportional Solenoid

(Hoist – Raise)E-7

21 9Y-1911 Oil Filter (Engine) B-8 53 Relief Valve (Brake Oil Cooler) E-7

22Brake Release Section of the Electric

Drive Pump54

Proportional Solenoid

(Hoist – Lower)F-7

23Secondary Steering Section of the

Electric Drive Pump55 143-9426 Makeup Tank (Brake) I-11

24 Load Sensing Valve 56 3E-6450 Pressure Switch (Steering Pump Oil) D-3

25 Relief Valve (Secondary Steering – Main) 57 Torque Converter Housing A-13

26 2G-6535 Slack Adjuster (Rear) F-12 / G-3 58 Transmission Hydraulic Control B-11

27 8P-1471 Relief Valve (Torque Converter Outlet) C-13 59 Transmission Housing A-11

28 9G-9208 Traction Control Valve G-1 60 200-5375Power Train Electronic Control Module

(ECM)C-1

29 141-4109 Oil Cooler (Rear Brake) F-11 61 212-0394 Relief Vavle (Vacum Breaker) C-1

30 6E-6640 Screen F-10 62 9X-4455 Pressure Switch Assembly C2

31 209-3406Prelubrication and QuickEvac Section of

the Electric Drive PumpB-6 / G-10

(*) 773E Only

(**) 775E Only

212-0394

D-2

B-7

G-10

D-2

Component Locations

*194-1465

**175-7852

175-7050

175-7051

209-3406

14

26

Hoist and Brake Hydraulic Tank

Steering Hydraulic Tank

Slack Adjuster Rear Brake (26)

Steering Metering Pump (14)

13 12 14 3 3247484950515253

LL

404137

3839

43444546

56 54

5542

KK

14

2930

33

35

DD

20

27GG

34

36

2324

2531

62

21PP

4 3567891011AA1213 151617BB18CC

19

12

2626

28

FF

HH

JJ

EE

58 RR

22

2832 4152 48 4734 36 53 544237

38 39

5146 162 101145 56 1555

4443

14

20

21

60

30

29

19

1 2658 59408 509 24 344957172712131822

Machine Component and Tap Locations

765

62

61

59

MM NN

24

QQ 60

61

57

35 33 23

3125

Tap

NumberDescription

Schematic

Location

AA Pressure Tap (Hoist) G-8

BB Pressure Tap (Lockup Clutch Maximum Pressure) B-12

CC Sampling Valve (Torque Converter Pressure) C-11

DD Oil Sampling Valve (Brake) G-8 / H-2

EE Pressure Tap (Transmission Lubrication Pressure) B-10

FF Pressure Tap (Rear Brake Service) F-12

GG Pressure Tap (Torque Converter Pressure) C-13

HH Pressure Tap (Parking Brake) D-12

JJ Pressure Tap (Brake Cooling) D-11

KK Pressure Tap (Steering) E-2

LL Sampling Valve (Steering Oil) B-3

MM Pressure Tap (Hoist Cylinder - Head End) D-8

NN Pressure Tap (Hoist Cylinder - Head End) D-8

PP Scheduled Oil Sampling Valve (Engine Oil) G-9

QQ Pressure Tap (Front Brake) L-7

RR Pressure Tap (Transmission Control) W-7

Tap Locations

Pressure, Sampling, and Sensor

Description Media Number

Specifications RENR6507

Systems Operation RENR6508

Testing and Adjusting RENR6509

Disassembly and Assembly SENR1574

Specifications: (Hydraulic System) RENR6515

Testing & Adjusting: (Hydraulic System) RENR6516

Specifications: (Steering System) RENR6510

Testing & Adjusting: (Steering System) RENR6511

Specifications: (Air System & Brakes) RENR6512

Testing & Adjusting: (Air System & Brakes) RENR6513

Specifications, Systems Operation, Testing &

Adjusting: (Oil Evacuation System)RENR3391

Specifications, Systems Operation, Testing &

Adjusting: (Suspension Cylinder)RENR6514

Schematic: (Electrical System) RENR6518

Automatic Electronic Traction Aid (AETA) SENR2986

Additional Manuals

Related Manuals

Power Train

Machine System

Electrical System

RR FF

LL

PP

KK

CC GG BBQQ

RENR6506-00

30Page,Color2,DGM

A

B

C

D

E

F

G

H

I

123456789101112

123456789101112

A

B

C

D

E

F

G

H

I

13

13

HYDRAULIC CIRCUIT COLOR DESCRIPTIONSPump Output(Brake)(Hoist)(Steering).

Pump Output(Brake Release)(Secondary Steering)(Prelube and Quickevac).

Pump Output(Transmission).

Supply Line.Drain/Return Line.Brake Circuit.Engine Prelube and Quickevac Circuit.Steering Circuit.Torque Converter/Transmission Circuit.Hoist Circuit.Traction Control Circuit.

M

12

14

1615

46

KK 20

24

43 44

4525

36

38

39

56

60

61

LL

23

22

31

CC

5

6

17

18

2

7

8

9

BB

27

35

GGEE

58

57

59

M

1

1

4

3

13

13

AA

10

11

15 19

47

32

26

29 30

50

48

49

53

52

51

22

40

FF

41

JJ

HH

37

DD

NNMM

54

55

23

31

42

32

47

1

26

1

10

28

19

Selector(4 Way)Solenoid

ProportionalSolenoid

DD

33

31

2322

21

M

Engine Prelubrication and Quickevac

Traction Control System

Steering Hydraulic System

Torque Converter and Transmission Hydraulic System

62

ECM

Main

LINEAR PATTERNS

Drain / Return Lines

Components

Pilot/Load Sensing Pressure

Pressure Line

THIS SCHEMATIC IS FOR THE 773E and 775E OFF HIGHWAY TRUCK

Components are shown installed on a fully operable machine with the key and engine

off and transmission shifter in neutral.