CAT 304C & 305C CR Mini Excavator Hydraulic System Schematic Manual - PDF DOWNLOAD

Component Locations Description

Machine

Accumulator Gp - Hydraulic, Charged

304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR

Cooler Gp -Hydraulic Oil Cylinder Gp - Arm Cylinder Gp -Blade Cylinder Gp -Boom Cylinder Gp -Boom Swing Cylinder Gp -Bucket Drive Gp -Swing Motor Drive Gp -Travel Motor (Left) Drive Gp -Travel Motor (Right) Filter As -Return Oil Manifold Pump Gp -Main & Pilot Swivel Gp Tank Gp -Hydraulic Oil Valve Gp -Boom Swing Solenoid Valve Gp -Check (Return Oil) Valve Gp -Check Valve Gp -Control (Main) Valve Gp -Control (Pilot Manifold) Valve Gp -Pilot (Arm / Swing) Joystick Valve Gp -Pilot (Blade) Joystick Valve Gp -Pilot (Boom/Bucket) Joystick Valve Gp -Pilot (Travel)

304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR

Part Number

Schematic Location

Description

Machine

087-4456

21

B-8

Coupling -Quick Disconnect (Female)

267-1079

1

B-98

Coupling -Quick Disconnect (Female)

282-8550 282-1537 293-7159 293-7158 282-8548 282-1535 266-6975

2

G-8

Coupling -Quick Disconnect (Male)

3

G-4

Coupling -Quick Disconnect (Male)

4

G-5

Cylinder Gp -Boom

5

F-9

Valve As. - Manual

G-7

Valve Gp - Aux. Pilot

266-6969 266-696776

6

282-1534

7

H-9

Valve Gp -Ball (Bucket Stop)

8

H-2

Valve Gp -Check (Boom Load)

300-4246 266-1533 300-4246 282-1533

Tap Locations Pressure and Sampling

Attachments Machine Location

9

H-4, H-5

Valve Gp -Diverter Sol (Boom Swing)

120-8757

10

A-10

Valve Gp -Selector (Pattern Change)

293-9743

17

B-7

Valve Gp -Pilot (Travel)

266-6942 266-6827

18

B-10

268-3054

19

F-2,F-3, F-3, F-4

265-8601

10

A-10

267-0424

20

C-6

093-5537

10

A-9

284-2243

1

B-98

304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR 304C CR 305C CR

Part Number

Machine Location

Schematic Location

153-2997

21

I-11, I-12

153-2994

22

B-12

153-2996

23

I-11, I-12

153-2995

24

B-12

270-9475 273-7025

25

D-12

RENR9636-02 May 2007

BASIC COMPONENT SYMBOLS

Tap Number

Description

Schematic Location

AA

Main Pump Pres. (at Main Control Valve)

F-2

BB

Pilot Pump Pressure Test Port

B-8

Hydraulic Oil Sampling Test Port

D-5

SOS

FLUID POWER SYMBOLS MAIN AUX.

PUMP or MOTOR

TWO POSITION

27

B-12

267-0424

28

B-13

P T SHIFTED POSITION

P T NORMAL POSITION

INFINITE POSITION

224-9575

29

I-12, I-12

284-4372

30

D-12

274-4203

31

I-11

268-3578

32

E-12

282-1540

16

G-12

VENTED

304C CR and 305C CR Mini Excavator Hydraulic System HWJ1-UP FPK1-UP

RETURN ABOVE FLUID LEVEL

PRESSURIZED

12

B-8

PRESSURE

ROTATING SHAFTS

FLOW

TEMPERATURE

13

SOLENOID or MANUAL

SOLENOID

BIDIRECTIONAL

SERVO

SOLENOID and PILOT or MANUAL

SOLENOID and PILOT

DETENT

THERMAL

MANUAL CONTROL SYMBOLS

MANUAL SHUTOFF

GENERAL MANUAL

PUSH BUTTON

PILOT CONTROL SYMBOLS

INTERNAL RETURN

SPRING LOADED

PEDAL

CROSSING AND JOINING LINES

LINES CROSSING

SPRING

REMOTE SUPPLY PRESSURE

SIMPLIFIED

GAS CHARGED

INTERNAL SUPPLY PRESSURE

COMPLETE

HYDRAULIC AND PNEUMATIC CYLINDERS

LINES JOINING

SINGLE ACTING

DOUBLE ACTING

INTERNAL PASSAGEWAYS

HYDRAULIC MOTORS

C-4 FIXED DISPLACEMENT

191-1392

14

C-3

267-0420

15

A-3

282-1539

UNIDIRECTIONAL

COMBINATION CONTROLS

HYDRAULIC PUMPS

267-0420

PILOT CONTROLLED

RETURN BELOW FLUID LEVEL

MEASUREMENT

ACCUMULATORS

274-4199

SHUTTLE

SPRING LOADED

BASIC SYMBOL

FLUID STORAGE RESERVOIRS

EXTERNAL RETURN

D-2 to F-10

FOUR-WAY

THREE-WAY

CHECK VALVES

RELEASED PRESSURE

11

TWO-WAY

AB

PUSH-PULL LEVER

282-8546 282-1513

16

VARIABLE DISPLACEMENT NON-COMPENSATED

FIXED DISPLACEMENT

VARIABLE DISPLACEMENT NON-COMPENSATED

UNIDIRECTIONAL

UNIDIRECTIONAL

BIDIRECTIONAL

BIDIRECTIONAL

FLOW IN ONE DIRECTION

15

TWO POSITION

THREE POSITION

INFINITE POSITIONING

PARALLEL FLOW

CROSS FLOW

FLOW ALLOWED IN EITHER DIRECTION

A-5

Printed in U.S.A.

© 2007 Caterpillar All Rights Reserved

AA 18

ATTACHMENT

LINE RESTRICTION VARIABLE and PRESSURE COMPENSATED

VALVE PORTS

CONTROL VALVES AB

4I-6188

HYDRAULIC PNEUMATIC ENERGY TRIANGLES

THREE POSITION

PUMP: VARIABLE and PRESSURE COMPENSATED

2-SECTION PUMP

VALVES

VALVE ENVELOPES

ONE POSITION

LINE RESTRICTION (FIXED)

RESTRICTION

PRESSURE COMPENSATION

LINE RESTRICTION (VARIABLE)

SPRING (ADJUSTABLE)

VARIABILITY

CONTROL VALVES

SPRING

FLUID CONDITIONER

10

2

Electrical Symbols Table Hydraulic Symbols (Electrical)

G

4 25

Electric Motor

Electrical Wire

Temperature Switch

Electrical Symbols (Electrical)

22 24 T

Temperature Symbol

Pressure Symbol LEFT RIGHT TRAVEL TRAVEL BLADE

28 16

22 24

32

BOOM

WORK BUCKET STICK TOOL

Wire Number Identification Codes

Electrical Schematic Example

Hydraulic Schematic Example Current Standard

Current Standard Harness identification code This example indicates wire 135 in harness "AG".

14 13 19 7

9

1

12 21 BB

11 36

Wire Circuit Number Identification

SOS

Wire Color

325-AG135 PK-14

26 8

Flow Symbol

SWING BOOM SWING

2

15

Level Symbol

325-PK Circuit Identification Number

6

Wire Color

Wire Gauge

Previous Standard Wire Color

Wire

325-PK-14

4 23

B Circuit Number Identification

17

30 3

BB BB 12

31 19 7

COMPONENT LOCATIONS

5

29

20

12

21

23 21

TAP LOCATIONS

A

Wire Gauge (EXAMPLE VALVE)

(Dimensions: 39 inches x 28 inches)

Pressure Switch (Adjustable)

Pressure Switch

Generator

30 Page,

10

Transducer (Gas / Air)

RENR9636-02

11

SOS

AA

Transducer (Fluid)

M

13

12

COUPLING 153-2996

I

11

COUPLING 153-2997

COUPLING 153-2996

BUCKET CYLINDER

A6

VALVE AS MANUAL STOP 224-9575

B6

Pa6

C1 C2

8

7

6

5

4

B9

3

2

DRIVE GP TRAVEL MOTOR (RIGHT) 305C CR: 266-1533

DRIVE GP TRAVEL MOTOR (RIGHT) 304C CR: 300-4246

DRIVE GP SWING MOTOR 282-1534

R/G

1

DRIVE GP TRAVEL MOTOR (LEFT) 305C CR: 282-1533

RED

RED

VALVE GP DIVERTER 274-4203

P1 A9

Pb9

Pb6

9

COUPLING 153-2997

BOOM SWING CYLINDER

VALVE AS MANUAL STOP 224-9575

10

D1

D2

D1

D2

P2

P3

P2

P3

DRIVE GP TRAVEL MOTOR (LEFT) 304C CR: 300-4246

I

R/G P

P

PS

PS

Pa9 DB

BUCKET FUNCTION

SECOND AUXILIARY ATTACHMENT SH

H

SECOND AUXILIARY ATTACHMENT

H

PG

VALVE GP PILOT (TRAVEL) 282-1540

P

P1

B

G

2

TRAVEL(RH)

P4

B

P1

A

B

P4

T P1

1 Pa2

A

5

Pb2

3

TRAVEL(LH)

Pa1

M

A

CYLINDER GP BUCKET 304C CR: 266-6969 305C CR: 266-6976

CYLINDER GP STICK 304C CR: 282-8550 305C CR: 282-1537

4 Pb1

F

Pb9 B9

A9

Pb8 B8

A8

Pb7

B7

A7

Pb6

B6

A6

Pb5 B5

Pi1 Dr1

A5

P2

P1

T1

G

SWIVEL GP 268-3054

VALVE GP ORIFICE SLOW RETURN Pb4 287-4804

VALVE GP CONTROL (MAIN) 304C CR: 282-8546 305C CR: 282-1513

CYLINDER GP BOOM SWING 266-6975

T2

CYLINDER GP BLADE 304C CR: 266-6987 305C CR: 266-6977

CYLINDER GP BOOM 304C CR: 282-8548 305C CR: 282-1535

SWITCH AS PILOT, TRAVEL 286-2305

TRAVEL ALARM FUNCTION ATTACHMENT

P2

F

E

F

E

SWIVEL GP 268-3054

B

D

B

D

SWIVEL GP 268-3054 A

C

A

C

SWIVEL GP 268-3054 G P

G P

AA A4

Pb3

B4

B3

A3

Pb2 B2

A2

Pb1 B1

F

A1 P PPS1

STICK CYLINDER

BOOM CYLINDER

(Dimensions: 39 inches x 28 inches)

30 Page, Color 2,

RENR9636-02

Pb7

Pa7 Pa4

E L1 R1

Pb4

B1 A1

C1 D1

A2 B2

D2 C2

E

VALVE GP SELECTOR ( 2- WAY) 268-3578

R3 L3

JOY STICK SIDE Pp22

PILOT PATTERN CHANGE ATTACHMENT

Pp21 Pp12 Pp11

D

CYLINDER GP BOOM 304C : 270-9475 305C : 273-7025

D

T3

T1

C2 Pa9

Pa8

Pa7

Pa6

Pa5

T3

Pa4

VALVE GP CHECK (PILOT OPERATED) 288-8571

Pa3

Pa2

A4

Pi1 B4

Pb4

Pa4

C

VALVE GP PILOT (STICK / SWING) JOYSTICK 267-0420

P T

BOOM LOWERING CHECK VALVE ATTACHMENT

COUPLING QUICK DISC (MALE) 153-2995

PP

VALVE GP PILOT (BLADE) JOYSTICK 191-1392

HYDRAULIC CIRCUIT COLOR DESCRIPTIONS MAIN PUMP OUTPUT PILOT PUMP OUTPUT SWING MOTOR CIRCUIT BOOM CYLINDER CIRCUIT STICK CYLINDER CIRCUIT LOAD SENSE CIRCUIT

T

PPS

A2

BOOM SWING A1 Pb9 Pa9

VALVE GP CHECK 284-2243

P

VALVE AS. MANUAL 4I-6188

P

B

ARM

Pb7

A

L1 Pa7

L2

SWING

Pb8

L4

2 BLADE Pb3

Pa8

SUPPLY LINE DRAIN / RETURN LINE RH TRAVEL MOTOR CIRCUIT BOOM SWING CYLINDER CIRCUIT

1 Pa3

TRAVEL MOTOR PILOT CIRCUIT LH TRAVEL CIRCUIT AUXILIARY OPTIONS CIRCUIT BLADE LIFT CIRCUIT BUCKET CYLINDER CIRCUIT

(TRAVEL)

(LOCK)

MANIFOLD 293-9743

T

AUXILARY CONTROL ATTACHMENT

M

PUMP GP MAIN/PILOT 304C CR: 266-6942 305C CR: 266-6827

T

PAC ACCUMULATOR GP HYDRAULIC, CHARGED 087-4456

A2 B5

A5

C

D

P

P

P

T

T

12

11

Component Group Attachment Air Line

1 Pa2

TRAVEL(RH)

2 Pb2

3 Pa1

VALVE GP CHECK RETURN OIL 093-5537

10

9

Pilot / Load Sensing Pressure

VALVE GP CONTROL PILOT MANIFOLD 274-4199 BOOM

R1

R2 BUCKET

CALLOUTS

R4

A

AUXILARY CONTROL ATTACHMENT

Pressure Line

Drain / Return Lines

R3 FILTER AS RETURN OIL 120-8757

LINE PATTERNS

VALVE GP PILOT (BOOM / BUCKET) JOYSTICK 267-0420

BB

COOLER GP HYD OIL 267-1079

TANK GP HYD OIL 265-8601

Pa5 Pb5

13

B

TO T3

TO TRAVEL VALVE

VALVE GP AUX. PILOT 267-0424

T

L3

COUPLING QUICK DISC (FEMALE) 153-2994

B

P

C

VALVE GP BOOM SWING SOLENOID 267-0424 PLS

A1

PLS

SOS

V2

P

Pa1

TRAVEL(LH)

4 Pb1

VALVE GP PILOT (TRAVEL) 282-1539

Pb4

Pa4

Pb6

Pa6

YY

Taps (Pressure, Sampling,Sensor) by letter

52

Components by number

THIS HYDRAULIC SCHEMATIC IS FOR THE 304C CR and 305C CR MINI-HYDRAULIC EXCAVATOR PART #: 266-6948 CHNG 02 AND 266-6829 CHNG 03 Components are shown installed on a fully operable machine with the key and engine off and transmission shifter in neutral.

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

8

7

6

5

4

3

2

1

A