©2003 CaterpillarAll Rights Reserved

Printed in U.S.A.

RENR5437-02June 2003

330C ExcavatorHydraulic SystemCYA1-UPHAA1-UPMCA1-UPJAB1-UPKDD1-UPGAG1-UP

GKX1-UPDKY1-UP

12 Main Control Valve

24 23 22 21 20 19 18 17 16

27

36

32

34

37 Pilot Oil Manifold

IN

T

OUT

BDr

Pi2A3

M1

M2

J2

J1

R3

A2

A1

M3

X2

X1

R2

S

S4A4

T2

B A

T1

T2

T1

A B

X X

TOUTPIN

PACPi1P2P1 PSA2

DR6DR5

PSA1

DR4DR3DR2DR1

PR

C

D

D

C

BA

G

F E

BP1 BT

(LOWER)

(OUT)

(IN)

T

(RAISE)

(REV)

(FWD)(R) (OPEN)

(CLOSE)

(L)

(FWD)

(REV)

P1P2

B2

A2 B1

B8B7B6C B5B4B3B2B1

A8A7A6A5A4A3A2A1

SDr

STSP1

SP2

Pi3 Di3 DST

(IN)

PRPL(OUT)

AR4R1BR4

AR3BR3AR2BR2

SPi

SP3

(RAISE)

AR1BR1

BR5Di4

Pi4

AL1

bL3

AR5AL4

BL1

CLO

SE

AL2

OP

EN

A1

R3BL2

BPi

AL3

DO

WN

R2

BP3

LR

R4

BP2

X3

bR4

aR5Pi1aR4

bR5HR

Di1

aR3

bR3

aR2

bR2

aR1

bR1

aL1

bL1HL

aL2

bL2bL4 Pi2

aL4

Di2

IN UP

R1

OU

T

M4

BL3aL3

AB

ItemComponent

STANDARD COMPONENTS

ComponentNo.ItemNo.

123456789

1011121314151617181920212223242526

Swing Motor

Travel Motor (Left)

Travel Motor (Right)

Stick Cylinder

2728293031323334353637383940414243444546474849505152

Hydraulic Tank

Gear Pump (Fan Motor)

Relief Valve (Fan Pump)

Fan Motor (Hydraulic Oil Cooler)

Return Filter

Oil Cooler

Pressure Sensor (Idler Pump)

Bypass Check Valve

Slow Return Check Valve

Pilot Pump

Idler Pump (View from Shaft End)

Pilot Filter

Pilot Relief Valve

Drain Filter

Pilot Oil Manifold

Travel Speed Solenoid Valve

Drive Pump (View from Shaft End)

Solenoid Valve (Hydraulic Activation) Valve

Swing Parking Brake Solenoid Valve

Pressure Sensor (Drive Pump) Reducing Valve (Boom/Swing Priority Mode)

Accumulator

Pressure Switch

Main Relief Valve

Pilot Control Valve (Boom and Bucket)

Pilot Control Valve (Swing and Stick)

Stick II Control Valve

Boom I Control Valve

Bucket Control Valve

Attachment Control Valve

Right Travel Control Valve

Left Travel Control Valve

Swing Control Valve

Stick I Control Valve

Boom II Control Valve

Pressure Switch

Pressure Switch

Boom Drift Reduction Valve Main Control Valve

Stick Drift Reduction Valve

Pilot Control Valve (Travel)

Swivel

Boom Cylinder

Bucket Cylinder

Travel Brake Valve (Right)

Travel Brake Valve (Left)

Power Shift Proportional Reducing Valve

MAIN CONNECTOR LINE

PILOT LINE

DRAIN LINE

Hydraulic Schematic190-7786

1 2

5

3

7 8

9

10 11 12 13

1415

16 17 18

1920 21 22

23 24

25 26

27

28

47

4443

52

3632 33

34

29

4849

38

39 40

3051

50

42

41

35

41

31

45

4

7

8

9

1

12 16 17 1918 20 21 22 23 24 27

42

49

52

63

4135

4

F04649

47

46

37

6