RENR3819-07August 2009

320C ExcavatorHydraulic System

Printed in U.S.A. 2009 Caterpillar, All Rights Reserved

BEA1-UPFBA1-UPGAA1-UPGLA1-UPMAA1-UPPAA1-UPANB1-UPBCB1-UPBDB1-UPMAB1-UPPAB1-UPAMC1-UPBBC1-UPBDC1-UPHBC1-UPCCD1-UPBDE1-UP

ALF1-UPDBG1-UPGNG1-UPJTG1-UPAKH1-UPAXK1-UPBBL1-UPEGL1-UPBCN1-UPSBN1-UPBER1-UPBPR1-UPHKT1-UPRAW1-UPBRX1-UPBMZ1-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)

PUMP(2 - SECTION)

SPRING(ADJUSTABLE)

VARIABILITY LINE RESTRICTION(VARIABLE)

PRESSURECOMPENSATION

PUMP(VARIABLE & PRESSURE

COMPENSATED)

MEASUREMENT

PRESSURE TEMPERATURE FLOW

ROTATING SHAFTS

UNIDIRECTIONAL BIDIRECTIONAL

PUSH - PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING

FIXEDDISPLACEMENT

VARIABLE DISPLACEMENTNON-COMPENSATED

UNIDIRECTIONAL

BIDIRECTIONAL

VALVE ENVELOPES VALVE PORTS

FLUID CONDITIONERPUMP OR MOTOR

FLUID POWER SYMBOLS

UNIDIRECTIONAL

BIDIRECTIONAL

RELEASED PRESSURE

EXTERNAL RETURN INTERNAL RETURN

REMOTE SUPPLY PRESSURE

SIMPLIFIED

HYDRAULIC PUMPS

ACCUMULATORS

SPRING LOADED GAS CHARGED

SOLENOID OR MANUAL

SOLENOID & PILOT

SOLENOID &PILOT OR MANUAL

SOLENOID SERVO THERMAL DETENT

HYDRAULIC & PNEUMATIC CYLINDERS

DOUBLE ACTINGSINGLE ACTING

BASICSYMBOL

SPRINGLOADED

CHECK VALVES

2 POSITIONINFINITE

POSITIONING

FLOW IN ONEDIRECTION

FLOW INEITHER

DIRECTION

3 POSITION

CROSSFLOW

PARALLELFLOW

INTERNAL PASSAGEWAYS

NORMAL POSITION

A B

P T

A B

P TSHIFTED POSITION INFINITE POSITION

CONTROL VALVES

ATTACHMENT

MANUAL SHUTOFF

SHUTTLE PILOTCONTROLLED

MAIN AUX

LINE RESTRICTION(VARIABLE & PRESSURE

COMPENSATED)

MANUAL CONTROL SYMBOLS

HYDRAULIC MOTORS

FLUID STORAGE RESERVOIRS

CROSSING & JOINING LINES

VALVES

PILOT CONTROL SYMBOLS

COMBINATION CONTROLS

BASIC COMPONENT SYMBOLS

ENERGY TRIANGLESHYDRAULIC PNEUMATIC

INTERNALSUPPLY PRESSURE

COMPLETE

FIXEDDISPLACEMENT

VARIABLE DISPLACEMENTNON-COMPENSATED

HYDRAULIC SYMBOLS (ELECTRICAL)

ELECTRICAL SYMBOLS TABLE

325-AG135 PK-14

HARNESS IDENTIFICATION CODE THIS EXAMPLEINDICATES WIRE 135 IN HARNESS AG

325-PK-14

WIRE GAUGE

WIRE COLOR

CIRCUIT NUMBERIDENTIFICATION

WIRE NUMBER IDENTIFICATION CODES

CURRENT STANDARD

PREVIOUS STANDARD

ELECTRICAL SCHEMATIC EXAMPLE HYDRAULIC SCHEMATIC EXAMPLE

325-PK

WIRE COLORCIRCUIT NUMBER

IDENTIFICATION

B

WIRE

WIRE

(EXAMPLE VALVE)

CURRENT STANDARD

TRANSDUCER(FLUID)

MELECTRIC MOTORTRANSDUCER

(GAS / AIR)

G

GENERATOR

PRESSURE SWITCH ELECTRICAL WIREPRESSURE SWITCH(ADJUSTABLE)

TEMPERATURESWITCH

PRESSURESWITCH

TEMPERATURESWITCH

LEVELSWITCH

FLOWSWITCH

ELECTRICAL SYMBOLS (ELECTRICAL)

A

CIRCUIT NUMBERIDENTIFICATION

WIRECOLOR

WIRE GAUGE

T

K

E

N

R

5

0

8

4

-

0

1

1

6

P

a

g

e

,

(

D

i

m

e

n

s

i

o

n

s

:

3

4

i

n

c

h

e

s

x

2

4

i

n

c

h

e

s

)

Pi4

HR

R3

HL

Pi2Pi1

AR5

aR5 aR4 aR3 aR2 aR1 aL1 aL2 aL3 aL4

AR4 AR3 AR2 AR1 Pi4 AL1 AL2 AL3 AL4

BR5 BR4 BR3 BR2 BR1 BL1 BL2 BL3 R2 Pi3

bR5 bR4 bR3 bR2 bR1 DST bL1 bL2 bL3 bL4

P1

P2

PIN

PSA2

PSA1

PAC

T-OUT(2)

DR2

RD3

RD4

Pi2

DR5

T-OUT(1)

DRG

45

46

48

47

23 22 21 20 19 18 16 15 1314

41PILOT OIL MANIFOLDf04860

17

30

10MAIN CONTROL VALVE

RE

N

R

3

8

1

9

-

0

7

1

6

P

a

g

e

,

(

D

i

m

e

n

s

i

o

n

s

:

3

4

i

n

c

h

e

s

x

2

4

i

n

c

h

e

s

)

THIS SCHEMATIC IS FOR THE 320C EXCAVATOR MEDIA NUMBER: RENR3819-07 PART NUMBER: 158-8176Components are shown installed on a fully operable machine.

Refer to the appropriate Service Manual for Troubleshooting, Specifications.

PILOT LINE

DRAIN LINE

IN

T

OUT

BDr

Pi2

(LOCK)

Pi

Dr1

A3 M1

M2

A1

A2

NO3

TOUT1PIN

PACPi1P2P1 PSA2

DR6DR5

PSA1

DR4DR3DR2DR1

BP1 BT

B A

T

(LOWER)

DR

RR

FR

U

(OUT)

(IN)

T

S1

G

F

S3

Pn1

PsM2

Ps1

PsM1

(RAISE)

(REV)

(FWD)(R) (OPEN)

(CLOSE)

(L)

(FWD)

(REV)

(TRAVEL)

T

P1P2

B2

A2 B1

B8B7B6C B5B4B3B2B1

A8A7A6A5A4

Pn2

A3A2A1

E

D

C

B

G3

SDr

PD6

ST

G4

DB6

Pm

PB2

SP1

A

SP2

Pi3 Di3 DST

(IN)

PRPL(OUT)

AR4

R1BR4AR3BR3AR2BR2

Dr2

Ps2

SPi

SP3

(RAISE)

AR1BR1

BR5Di4

Pi4

AL1

bL3

AR5

G2

G1

AL4

DB2

BL1

C

L

O

S

E

AL2

O

P

E

N

A B

DB1

A1

R3BL2

BPi

AL3

PB1

D

O

W

N

R2

BP3

L

R

BP2

bR4

aR5Pi1aR4

bR5HR

Di1

aR3

bR3

aR2

bR2

aR1

bR1

aL1

bL1HL

aL2

bL2bL4 Pi2

aL4

Di2

I

N

U

P

Pp3Pp3

O

U

T

NO1

TOUT2

(SWPARKING)

BL3aL3

MU

DR

AB

PG

1 2 3

4

5 6 7 8

9

11

1

ItemComponent

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

ComponentNo.ItemNo.

21

22

23

COMPONENTS

Swing Motor

Left Travel Motor

Right Travel Motor

Bucket Cylinder

Swivel

Stick Drift Reduction Valve

Swing Control Valve

Right Travel Control Valve

Attachment Control Valve

Bucket Control Valve

Line Relief Valve (Stick Cylinder Head End)

Straight Travel Control Valve

24

25

26

27

28

29

30

Stick Unloading Valve

Main Relief Valve

Stick Cylinder

Boom Cylinder

Boom II Control Valve

Stick I Control Valve

Left Travel Control Valve

Straight Travel Control Solenoid

Stick Regeneration Valve

Negative Flow Control Relief Valve

Boom I Control Valve

Boom Drift Reduction Valve

Main Control Valve

Stick II Control Valve

Line Relief Valve (Bucket Cylinder Rod End)

Line Relief Valve (Bucket Cylinder Head End)

Boom Regeneration Valve

Pressure Switch

Pressure Switch

Pilot Control Valve (Swing and Stick)

Pilot Control Valve (Boom and Bucket)

Pressure Switch

Accumulator

Reducing Valve (Boom/Swing Priority Mode)

Pressure Sensor (Left Pump)

Travel Speed Solenoid Valve

34

35

32

33

31

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

37

36

53

54

55

56

57

58

59

Valve

Left Pump

Pilot Pump

Slow Return Check Valve

Bypass Check Valve

Return Filter

Right Pump

Pilot Relief Valve

Pilot Filter

Pressure Sensor (Right Pump)60

Oil Cooler

Pilot Control Valve (Travel)

Negative Flow Control Relief Valve

Travel Brake Valve (Left)

Travel Brake Valve (Right)

Line Relief Valve (Boom Cylinder Rod End)

Swing Parking Brake Solenoid Valve

Solenoid Valve (Hydraulic Activation)

Pilot Oil Manifold

1012

13 14 1516 18

19 20 21 22 23 24

25

17

28 302627

29

31 32 33 34

35

36 37

38

39

40 41 42

43

44

45 46 47 48

49

5051

52

53

55

56

57 58 59 60

54

Variable Swing Priority Valve

Hydraulic Tank

Case Drain Filter

7

4

8

9

55

5610

1535859574950543625

f04859

MAIN CONNECTOR LINE