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INTERACTIVE SCHEMATIC

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Cover PageTables

SchematicMachine Views

ComponentConnector

Chassis View

Cab View

Engine View

Features

Options

Bookmarks X

EC-C3EC-C2 E-C60

EC-C1

E-C61

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FUNCTION Zoom In

HOTKEYS (Keyboard Shortcuts)

Zoom OutFit to PageHand Tool

“CTRL” / “+”

KEYS

“CTRL” / “-”“CTRL” / “0” (zero)“SPACEBAR” (hold down)

Find “CTRL” / “F”

PressureSwitch

TemperatureSwitch

LevelSwitch

FlowSwitch Circuit Breaker

T

ELECTRICAL SYMBOLS

Spring(Adjustable)

Variability

FluidConditioner

Pumpor Motor

BASIC HYDRAULICCOMPONENT SYMBOLS

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SCHEMATIC SYMBOLS AND DEFINITIONS

HYDRAULIC SYMBOLS - ELECTRICAL

Transducer(Fluid)

Transducer(Gas / Air)

G

Generator ElectricalWire

Pressure Switch

MElectricMotor

Pressure Switch (Adjustable)

TemperatureSwitch

PressureSwitch

TemperatureSwitch

LevelSwitch

FlowSwitch Circuit Breaker

T

ELECTRICAL SYMBOLS

Spring

ControlValves

Restriction Line Restriction(Fixed)

2-SectionPump

MAIN AUX.

Spring(Adjustable)

Variability

Line Restriction(Variable)

PressureCompensation

Pump: Variable andPressure Compensated

Hydraulic PneumaticEnergy Triangles

FluidConditioner

Attachment

Pumpor Motor

BASIC HYDRAULICCOMPONENT SYMBOLS

Line RestrictionVariable and Pressure

Compensated

Vented Pressurized Return Above Fluid Level Return Below Fluid Level

FLUID STORAGE RESERVOIRS

Pressure Temperature Flow

MEASUREMENT

Unidirectional Bidirectional

ROTATING SHAFTS

One Position Two Position Three Position

Two-way Three-Way Four-Way

ENVELOPES

PORTS

CONTROL

BasicSymbol

SpringLoaded

Normal Position

A B

P T

A B

P TShifted Position Infinite Position

Shuttle PilotControlled

VALVES

CHECK

Solenoidor Manual

Solenoidand Pilot

Solenoid and Pilot or Manual

Solenoid Servo Thermal Detent

COMBINATION CONTROLS

T

Fuse: A component in an electrical circuit that will open the circuit if too much current flows through it.

Switch (Normally Open): A switch that will close at a specified point (temp, press, etc.). The circle indicatesthat the component has screw terminals and a wire can be disconnected from it.

Switch (Normally Closed): A switch that will open at a specified point (temp, press, etc.). No circle indicates that the wire cannot be disconnected from the component.

Ground (Wired): This indicates that the component is connected to a grounded wire.The grounded wire is fastened to the machine.

Ground (Case): This indicates that the component does not have a wire connected to ground. It is grounded by being fastened to the machine.

Reed Switch: A switch whose contacts are controlled by a magnet. A magnet closes the contacts ofa normally open reed switch; it opens the contacts of a normally closed reed switch.

Sender:

A component that is used with a temperature or pressure gauge. The sender measures the temperature or pressure.Its resistance changes to give an indication to the gauge of the temperature or pressure.

Relay (Magnetic Switch): A relay is an electrical component that is activated by electricity.It has a coil that makes an electromagnet when current flows through it.The electromagnet can open or close the switch part of the relay.

Solenoid: A solenoid is an electrical component that is activated by electricity. It has a coil that makes an electromagnet when current flows through it.The electromagnet can open or close a valve or move a piece of metal that can do work.

Magnetic Latch Solenoid: An electrical component that is activated by electricity and held latched by a permanent magnet. It has two coils (latch and unlatch) that make electromagnet when current flows through them. It also has an internal switch that places the latch coil circuit open at the time the coil latches.

BASIC ELECTRICAL COMPONENT SYMBOLS

Push-pull Lever PedalGeneral Manual Push Button SpringManual Shutoff

MANUAL CONTROL

External Return Internal Return

Simplified CompleteInternal

Supply Pressure

RELEASED PRESSURE

REMOTE SUPPLY PRESSURE

PILOT CONTROL

Spring Loaded Gas Charged

ACCUMULATORS

Crossing Joining

LINES

Double ActingSingle Acting

CYLINDERSUnidirectional

Bidirectional

FIXED DISPLACEMENT

VARIABLE DISPLACEMENTNON- COMPENSATED

PUMPS

Unidirectional

Bidirectional

Unidirectional

Bidirectional

FIXED DISPLACEMENT

VARIABLE DISPLACEMENTNON- COMPENSATED

MOTORS

Unidirectional

Bidirectional

TwoPosition

InfinitePositioning

FLOW IN ONEDIRECTION

FLOW ALLOWED INEITHER DIRECTION

ThreePosition

CROSSFLOW

PARALLELFLOW

INTERNAL PASSAGEWAYS

1

2

AG-C4111-7898

L-C123E-5179

9X-1123 ComponentPart Number

Pin or Socket Number

Part Number: forConnector Plug

Harness Identification Letter(s): (A, B, C, AA, AB, AC, ...)

Plug

325-AG135 PK-14

Wire ColorWire Gauge

Receptacle

1

12

2Sure-Seal connector: Typical representationof a Sure-Seal connector. The plug and receptacle contain both pins and sockets.

Deutsch connector: Typical representationof a Deutsch connector. The plug contains all sockets and the receptacle contains all pins.

Fuse (5 Amps)

5A

Harness identification code:This example indicates wire group 325,

wire 135 in harness "AG".

L-C123E-5179

Wire, Cable, or Harness Assembly Identification: Includes Harness Identification Letters and Harness Connector Serialization Codes (see sample).

Harness Connector Serialization Code: The "C" stands for "Connector" and the number indicates which connector in the harness (C1, C2, C3, ...)

HARNESS AND WIRE SYMBOLS

UENR3880November 2012

434F Backhoe LoaderHydraulic System434F:LDH1-UPFLY1-UP

Printed in U.S.A.© 2012 Caterpillar, All Rights Reserved

COMPONENT TABLE

* COMPONENTS NOT SHOWN

Description Part Number

Machine Location

Schematic Location

Pump GP -Implement 307-3063 1 B-5 Tank -Hydraulic 358-9301 2 A-5 TANK GROUP -Filter/ Breather / Sight Gage 351-5888 3 A-5 Cooler -Hydraulic 337-9751 4 B-4 Filter -Hydraulic 361-6768 5 B-3 Valve HMU -Load Sense Relief 341-7654 6 C-6 Cylinder -Front Steer 217-5097 7 B-6

LH: 374-8060 RH: 374-8059

Cylinder -Tilt 370-7083 9 B-8 Cylinder -MP Bucket (OPT) 185-1839 10* A-8 Cylinder -Stab 320-5938 11 F-6 Cylinder -Boom 320-5936 12 F-6 Cylinder -Stick 320-5932 13 F-4

LH: 381-8055 F-5

RH: 381-8054 Cylinder -Bucket 320-5937 15 F-4 Cylinder -E-Stick (OPT) 320-5935 16 F-3 Accumulator -Pilot 149-0686 17 D-5 Valve -Ride Control (OPT) 245-8780 18 C-8 Accumulator -Optional 382-8033 19 C-8 Sensor -Ride Control (OPT) 344-7391 20 C-8 Valve -Loader (PL/IT) 359-7209 21 C-7 Valve -Backhoe 359-7214 22 F-7 Valve -Cushion 320-7812 23* F-5 Valve -Check (Stab) 308-3437 24 F-6 Valve -Boosted Brake 220-8226 25 D-3 Manifold -Brake 373-6966 26 D-5 Valve GP -AWS 373-6998 27 A-5 Valve -Boom Hose Burst 389-3096 28 F-6 Valve -Stick Hose Burst 347-1127 29 F-4 Valve -Lift Hose Burst 262-7081 30 B-8 Valve -Tilt Hose Burst 262-7079 31 B-8 Valve -Power Side Shift 351-1637 32* B-2 Cylinder -Power Side Shift 347-2223 33* B-3 Valve -Coupler (HOE) 358-2091 34* A-3 Cylinder -Coupler (HOE) 361-1139 35* B-3 Solenoid - Object Lifting 332-6408 36* X-X Valve - Check (Dual Back Pressure) 424-2971 37* X-X

Cylinder -Swing

8

14

Cylinder -Lift B-8

COMPONENT LOCATIONS

TAP TABLE

Tap Number Description Schematic Location

T1 PUMP DISCHARGE PRESSURE C-5T2 RIGHT REAR SERVICE BRAKE C-4T3 REAR PARK BRAKES D-5

TAP LOCATIONSPressure, Sampling, Sensor

12345678

A

B

C

D

E

F

12345678

A

B

C

D

E

F

DRAIN / RETURN LINE

HYDRAULIC CIRCUIT COLOR DESCRIPTIONSIMPLEMENT AND STEERING PUMP CIRCUIT

SWING CYLINDER CIRCUIT

STEERING CYLINDER CIRCUIT

PILOT OIL CIRCUIT

BUCKET CYLINDER CIRCUIT

STICK CYLINDER CIRCUIT

LOAD SENSE CIRCUITSUPPLY LINE

E-STICK CYLINDER CIRCUIT

BOOM CYLINDER CIRCUITSTABILIZER CYLINDER CIRCUIT

BOOSTED BRAKE OIL CIRCUIT

LIFT CYLINDER CIRCUITTILT CYLINDER CIRCUITLOADER VALVE CIRCUIT

POWER SIDE-SHIFT CYLINDER CIRCUITSIDE-SHIFT LOCK CYLINDER CIRCUIT

COUPLER CIRCUIT (HOE)

LINE PATTERNS

Drain / Return Lines

Component Group

Pilot / Load Sensing Pressure

Pressure Line

CALLOUTS

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

(52) VALVE GP - CONTROL138-1234

Callout Number(Machine Location from

Component LocationsTable)

ComponentName

Part Number

Components are shown installed on a fully operable machine with the key and engine off, transmission shifterin neutral and with parking brake set.Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.

SCHEMATIC PART NUMBER: 362-9204, CHANGE: 02, VERSION: -

434F BACKHOE LOADER HYDRAULIC SYSTEM SCHEMATICMEDIA NUMBER: UENR3880

T2

T1

T3

(3) TANK GROUP - FILTER / BREATHER / SIGHT GAGE

(2) TANK - HYDRAULIC

(4) COOLER - HYDRAULIC

(1) PUMP GP - IMPLEMENT

(7) CYLINDER - FRONT STEER

(27) VALVE GP - AWS (434F ONLY)

(5) FILTER - HYDRAULIC

(25) VALVE - BOOSTED BRAKE

(26) MANIFOLD - BRAKE

(17) ACCUMULATOR - PILOT

(6) VALVE HMU - LOAD SENSE RELIEF

(20) SENSOR - RIDE CONTROL (OPT)

(19) ACCUMULATOR - OPTIONAL

(18) VALVE - RIDE CONTROL (OPT)

(8) CYLINDER - LIFT

(9) CYLINDER - TILT

(10) CYLINDER -MP BUCKET (OPT)

(16) CYLINDER - E STICK(OPT)

(11) CYLINDER - STAB

(24) VALVE - CHECK (STAB)

(13) CYLINDER - STICK

(14) CYLINDER - SWING

(15) CYLINDER - BUCKET

(29) VALVE - STICK HOSE BURST

(23) VALVE - CUSHION

(11) CYLINDER - STAB

(12) CYLINDER - BOOM

(24) VALVE -CHECK (STAB)

(28) VALVE - BOOM HOSE BURST

(22) VALVE - BACKHOE

(31) VALVE - TILT HOSE BURST

(30) VALVE - LIFTHOSE BURST

(21) VALVE - LOADER (PL/IT)

D

DLS

LIFT

TILT

AUX

FRONT STEER CYL.

ACC

R

T

PS

H

RH STAB BOOM SWING BUCKET STICK LH STABE-STICK

A4 B4B3 A6 B6A1 B1

P

A1

B1

A2

B2

A3

B3

A3

LEFTBRAKEPEDAL

TO REAR AXLELEFT WHEEL

BRAKE

TO REAR AXLERIGHT WHEEL

BRAKE

SULIFT

TILT

AUX

A2 B2 A5 B5 A7 B7

SIDESHIFTLOCK

F1F2

R2

R1

REAR STEER CYLINDER

FRONT STEER CYL.

AWS VALVE 434F ONLY

HMU-RHMU-L

R L

B A

NOTE B

P8

LS8

T8

T7P7

B A

RIGHTBRAKEPEDAL

LH:RH:

T8

P8

LSC1 C2

P

T

POWERED SIDESHIFT

LS8

BACKHOE COUPLER

T7

P7

T

P

P

V2

C2

T

V2

PIL

BL

351-5888

358-9301

337-9751

307-3063

214-5097

373-6998

361-6768

220-8226

373-6966

149-0686

341-7654

382-8033

245-8780

370-7083

185-1839

320-5935

320-5938

308-3437

320-5932

381-8054381-8055

320-5937

347-1127

320-7812

320-5938

320-5936

308-3437

389-3096

359-7214

262-7079

262-7081

347-2223

351-1637

358-2091

347-2223

374-8060LEFT:

344-7391

374-8059RIGHT:

359-7209

OPTIONAL ATTACHMENT

OPTIONAL ATTACHMENT

OPTIONAL ATTACHMENT

424-2971

OPTIONAL ATTACHMENT

332-6408

(37) VALVE - CHECK

(33) CYLINDER -POWER SIDE SHIFT

(32) VALVE -POWER SIDE SHIFT

(34) VALVE - COUPLER(HOE)

(35) CYLINDER -COUPLER (HOE)

(36) SOLENOID - OBJECT LIFTING

REAR MACHINE VIEW

15

14

1312

UNDER CAB VIEW

T3

T2

T1

27

26

25

22

21

20

19

18

17

6

5

32

1

LEFT SIDE VIEW

29

28

24

11

4

FRONT VIEW

31

30

9

8

7

BOOM WITH E-STICK VIEW

16