RENR7357
30 Page: (Dimensions: 39 inches x 28 inches)
October 2006
©
2006 Caterpillar
All Rights Reserved
Printed in U.S.A.
345C Excavator
Hydraulic System - Attachment
System 12: Two Way / One Pump Flow / Pedal
RENR7357
SPC1-UP
GPH1-UP
GCL1-UP
GJR1-UP
ELS1-UP
LYS1-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)
VARIABILITY
LINE RESTRICTION
(VARIABLE)
LINE RESTRICTION
VARIABLE and PRESSURE
COMPENSATED
PRESSURE
COMPENSATION
PUMP: VARIABLE and
PRESSURE 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 CONDITIONER
PUMP or MOTOR
FLUID POWER SYMBOLS
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
VALVES
PILOT CONTROL SYMBOLS
RELEASED PRESSURE
EXTERNAL RETURN
INTERNAL RETURN
REMOTE SUPPLY PRESSURE
SIMPLIFIED
COMPLETE
INTERNAL
SUPPLY PRESSURE
ACCUMULATORS
SPRING LOADED
GAS CHARGED
SOLENOID
or MANUAL
SOLENOID
and PILOT
SOLENOID and
PILOT or MANUAL
COMBINATION CONTROLS
SOLENOID
SERVO
THERMAL
DETENT
HYDRAULIC AND PNEUMATIC CYLINDERS
DOUBLE ACTING
SINGLE ACTING
BASIC
SYMBOL
SPRING
LOADED
CHECK VALVES
TWO
POSITION
INFINITE
POSITIONING
FLOW IN ONE
DIRECTION
FLOW ALLOWED IN
EITHER DIRECTION
THREE
POSITION
CROSS
FLOW
PARALLEL
FLOW
INTERNAL PASSAGEWAYS
NORMAL POSITION
A B
P T
A B
P T
SHIFTED POSITION
INFINITE POSITION
CONTROL VALVES
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOT
CONTROLLED
Hydraulic Symbols (Electrical)
Electrical Symbols Table
325-AG135 PK-14
Circuit Identification
Number
Wire Color
Wire Gauge
Harness identification code
This example indicates
wire 135 in harness "AG".
325-PK-14
Wire Gauge
Wire Color
Circuit Number
Identification
Wire Number Identification Codes
Current Standard
Previous Standard
Electrical Schematic Example
Hydraulic Schematic Example
325-PK
Wire Color
Circuit Number
Identification
B
A
Wire
Wire
(EXAMPLE VALVE)
Current Standard
Transducer
(Fluid)
Transducer
(Gas / Air)
G
Generator
Electrical Wire
Pressure Switch
M
Electric Motor
Pressure Switch
(Adjustable)
Temperature Switch
T
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Flow
Symbol
Electrical Symbols (Electrical)
2
PUMP & FILTER GROUP
MACHINE COMPONENT LOCATIONS
40
214344
21 22
23
3429
38
31
3524 25 263045
39
28
46
37
19 4236 41
2732
2321
24 253045 2839 26 35 4219 3633
32 27 29 31 38
43
34 44 404637 41
22
33
BBDD
CC
SOS
AA
Description
Part
Number
Machine
Location
Schematic
Location
Pump Gp - Gear (Auxilary) 136-8899 33 B-3
Valve Gp - Solenoid (Work Tool) 190-7820 33 D-1
Valve Gp - Bank 2 239-9031 33 E-3
Accumulator Gp - Pilot Manifold Note B 19 B-5
Cylinder Gp - Boom Note A 21 E-6
Cylinder Gp - Bucket Note A 22 F-6
Cylinder Gp - Stick Note B 23 F-6
Filter Gp - Return Note B 24 A-6
Filter Gp - Pilot Note B 25 A-4
Filter Gp - Drain Return Note B 26 A-6
Motor Gp - Cooling Fan Note B 27 A-7
Motor Gp - Left Travel Note B 28 F-5
Motor Gp - Right Swing Note B 29 F-7
Motor Gp - Right Travel Note B 30 F-4
Motor Gp - Swing Left Note B 31 F-8
Pump Gp - Cooling Fan Note B 32 B-2
Pump Gp - Drive / Idler / Pilot Hydraulic Note B 33 B-3
Swivel Gp Note B 34 E-4
Tank Gp - Hydraulic Oil Note B 35 A-6
Valve Gp - Boom/Swing Priority Note B 36 B-4
Valve Gp - Cooler Bypass Check Note B 37 B-7
Valve Gp - Left Swing Motor Note B 38 E-7
Valve Gp - Left Travel / Brake Note B 39 E-5
Valve Gp - LH Pilot Control (Stick/Swing) Note B 40 C-8
Valve Gp - Main Control Note B 41 D-2 thru D-6
Valve Gp - Pilot Manifold Note B 42 B-5 thru B-6
Valve Gp - Pilot Travel Note B 43 D-7 , D-8
Valve Gp - RH Pilot Control (Bucket/ Boom) Note B 44 C-7
Valve Gp - Right Travel / Brake Note B 45 E-4
Valve Gp - Slow Return Check Note B 46 B-8
Note A: Refer to parts manual for specific cylinder information.
Note B: Part Numbers are located on the main Hydraulic System Schematic according to the
effectivity of the machine.
Component Locations
Attachment
Standard 345C
2
41
3
WORK TOOL GROUP
EE FF
EE FF
HYD.
TANK
View C-C
View B-B
FWD
2
13
33
3 1
Tap
Number
Description
Schematic
Location
AA Pilot Pump Delivery Pressure A-4
BB Drive Pump Delivery Pressure B-2
CC Pump Power Shift Pressure A-2
DD Idler Pump Delivery Pressure A-2
EE Work Tool Pressure (A1) D-1
FF Work Tool Pressure (A2) D-1
SOS Hydraulic Oil Sampling Port A-4
RENR7357
30 Page: (Dimensions: 39 inches x 28 inches)
DRAIN / RETURN LINE
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
DRIVE PUMP OUTPUT
IDLER PUMP
POWER SHIFT CONTROL CIRCUIT
PILOT PUMP OUTPUT
COOLING FAN PUMP
ATTACHMENT CONTROL CIRCUIT
SUPPLY LINE
BUCKET CONTROL & BUCKET CYLINDER CIRCUIT
RIGHT TRAVEL CONTROL & RIGHT TRAVEL MOTOR CIRCUIT
TRAVEL SPEED CONTROL CIRCUIT
STICK CONTROL & STICK CYLINDER CIRCUIT
BOOM CONTROL & BOOM CYLINDER CIRCUIT
NEGATIVE FLOW CONTROL
LEFT TRAVEL CONTROL & LEFT TRAVEL MOTOR CIRCUIT
SWING CONTROL & SWING MOTOR CIRCUIT
SWING BRAKE CONTROL CIRCUIT
WORK TOOL
DRIVE/IDLER
A4
B1
Dr1
Di
PS2 PB
Pi2
D0 PS1
Pi1
a2
a5
a3
A2
a1
a4
A1
PSV
PUMP GP
136-8899
B
S L
L1
X
PR
PL
P1 P2
T
B1
A1 B2 A2
PC
PG
T
OUT
IN
8
1
6
A
P
T
5
7
Pi1
P2
P-IN
PSA2
DR1
T-OUT2
DR2
DR3
DR4 Pi2 DR5
DR6
T-OUT1
P1
PSA1
NO.1
(TRAVEL)
NO.2
(SWING)
NO.3
(LOCK)
DR
DR1
L2
L3
A
B
SWINGSTICK BOOMBUCKET
OUT
IN
R L
OPEN CLOSE
DOWN
UP
JLP
JLT
JL1
JL3
JL2
JL4
JR4
JR2 JR3 JR1
JRP
JRT
A1 A2 A3 A4 A5 A6 A7 A8
B1 B2 B3 B4 B5 B6 B7 B8
aR4 bL3 bL4 aL3 aR3 bR2 bR3 aR2
µµµ µµµµ µ
TRAVEL(R)TRAVEL(L)
TP
TT
BACK
FWD FWD
T2
T1
T3
T4
BACK
bR1 aR1 aL1 bL1
µµµ µ
BUCKET CYLINDER
PG2
PB2
DE2
B2
A2
PA2
M2
DB2
PG1
PB1
DE1
B1A1
PA1
M1
DB1
B
A
AR2 BR2
BOOM
CYLINDER
BOOM
CYLINDER
STICK CYLINDER
X
B
A
AG
BG
L
T2
T1
BR
BR3 AR3AL3BL3
BL4 AL4
AR1BR1
B
A
AG
BG
L
T2
T1
BR
X
VALVE GP
232-4103
M
LS
PB
AL1 BL1
P
T
A
B
PA
BOOM(1)
STICK(2)
HL
aL5
Dr
R2
X
dL5(DOWN)
BPi
BDr
(UP)
(IN)
VALVE GP
190-7820
aL4
T
P
A1
A2
(OUT)
AL3
BL4
AL4
BUCKET
ATCH
TRAVEL(R)
TRAVEL(L)
SWING
Pp1
(CLOSE)
AL2
BL2
(OPEN)
bL2
(B)
(F)
PTA
PSW
(BACK)
(FWD)
dST1
(BACK)
(F)
(B)
(R)
(FWD)
(L)
Pp2
PiH
BR2
AR2
bR2 BR1
AR1
bR1
bL1
BL1
AL1
bL3
BL3
aR1 PR
PL
aL1 aL3 bL4
PAT
STICK(1)
BOOM(2)
R1
Y
HR
AR4
R3
dR4
(L)
(R)
PiL
(IN)
(OUT)
APi
ADr
(UP)
APi2
dR5
AR3
BR3
aR3
bR3 aR2
aR4
dSW
1
2
3
4
5
6
7
8
C
D
E
F
1
23
4
56
7
8
A
B
C
D
E
F
B
VALVE GP
LH PILOT CONTROL
STICK/SWING
VALVE GP
RH PILOT CONTROL
BUCKET/BOOM
VALVE GP
PILOT CONTROL
TRAVEL
VALVE GP
LEFT
TRAVEL/BRAKE
MOTOR GP
LEFT SWING
VALVE GP
LEFT SWING MOTOR
MOTOR GP
RIGHT SWING
MOTOR GP
RIGHT TRAVEL
VALVE GP
RIGHT
TRAVEL/BRAKE
SWIVEL GP
VALVE GP
MAIN CONTROL
MOTOR GP
LEFT TRAVEL
MOTOR GP
COOLING FAN
VALVE GP
CHECK
SLOW RETURN
VALVE GP
CHECK COOLER
BYPASS
FILTER GP
DRAIN RETURN
TANK GP
HYDRAULIC
FILTER GP
RETURN
VALVE GP
PILOT
MANIFOLD
ACCUMULATOR GP
PILOT MANIFOLD
FILTER GP
CASE DRAIN
VALVE GP
BOOM/SWING
PRIORITY
FILTER GP
PILOT
PUMP GP
COOLING FAN
PUMP GP
& PILOT
THIS SCHEMATIC IS FOR THE 345C (ATTACHMENT)
PART #: 239-8956 (HE00)
Components are shown installed on a fully operable machine with the key and engine
of and transmission shifter in neutral.
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling,Sensor) by letter
Components
YY
52
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations
Control (Median Pressure)
SOLENOID (WORK TOOL)
(AUXILARY)
B2
B1
FINE SWING
FF
EE
BB
CC
DD
SOS
AA
by number
