INTERACTIVE SCHEMATIC
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EC-C3
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©
2003 Caterpillar, All Rights Reserved
Printed in U.S.A.
RENR1905-02
November 2003
345B Excavator
Hydraulic System
BFG1-UP
7KS1-UP
9GS1-UP
4SS1-UP
2SW1-UP
COMPONENT LOCATION
Description
Part
Number
Machine
Location
Schematic
Location
Motor GP-Swing(Left) 123-1998
1
F-7
Motor GP-Swing(Right) 147-5789
2
F-7
Motor GP-Travel(Left) 137-3791
3
F-6
Motor GP-Travel(Right) 137-3791
4
F-5
Valve GP-Travel Counterbalance(Left) 111-9993
6
E-6
Valve GP-Travel Counterbalance(Right) 111-9993
7
E-5
Swivel GP 137-3796
10
E-5
Switch AS-Pressure(Boom Raise) 106-0180
11
E-4
Valve GP-Relief 239-8976
13
D-6
Valve GP-Main Control 122-7760
14
D-5
Switch AS-Pressure(Implement/Swing) 106-0179
15
D-5
Valve GP-Relief 177-2708
17
D-3
Valve GP-Pilot 123-2148
19
C-8
Valve GP-Load Control 156-0844
20
D-7
Valve GP-Load Control - Stick Lowering Control 202-9264
21
D-6
Valve GP-Check and Relief 155-3872
25
C-5
Valve GP-Load Control 156-0844
29
D-4
Valve GP-Load Control - Stick Lowering Control 202-9264
30
D-3
Valve GP-Relief 177-2708
31
C-7
Valve GP-Regeneration 140-0672
32
C-6
Valve GP-Pressure Control 122-7708
34
C-6
Valve GP-Relief(Bucket Cylinder Head End) 177-2708
36
C-4
Valve GP-Relief(Bucket Cylinder Rod End) 177-2708
37
C-4
Valve GP-Relief(Boom Cylinder Rod End) 177-2708
38
C-3
Valve GP-Relief-Negative Flow Control 122-7750
39
C-3
Valve GP-Pilot 123-2147
40
B-7
Filter GP-Oil 4I-3741
41
B-4
Valve GP-Selector 107-7058
42
B-7
Accumulator GP-Hydraulic-Uncharged 087-4456
43
B-5
Valve GP-Pilot 123-2146
44
B-4
Filter GP-Oil-Hydraulic oil 126-2075
45
B-7
Valve GP-Solenoid(Fine Control) 121-1491
46
B-6
Valve GP-Solenoid(Travel Speed) 121-1491
47
B-6
Valve GP-Solenoid(Swing) 121-1491
48
B-5
Valve GP-Relief 143-8145
50
B-5
Manifold GP-Control 111-9950
51
B-5
Sensor AS-Pressure 106-0178
54
B-3
Valve GP-Check 185-0384
57
A-7
Valve As-Check (Cooler Bypass) 123-2505
58
A-7
Filter GP-Oil 126-2112
59
A-6
Cooler GP Engine Oil 115-2990
60
A-7
Radiator GP 139-8823
61
A-7
Motor GP-Piston 155-9107
62
A-7
Tank & Filter GP-Hydraulic 126-2111
63
A-6
Valve GP-Relief 143-8144
64
A-7
FLUID POWER SYMBOLS
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
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 ACTINGSINGLE 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
ELECTRICAL SYMBOLS
Hydraulic Symbols (Electrical)
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
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Flow
Symbol
Electrical Symbols (Electrical)
T
Components are shown installed on a fully operable machine with the key and engine off, transmission shifter
in neutral and with parking brake set.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.
SCHEMATIC PART NUMBER: 115-3138, CHANGE: 09, VERSION: V
MEDIA NUMBER:
THIS SCHEMATIC IS FOR THE 345B EXCAVATOR HYDRAULIC SYSTEM
12345678
A
B
C
D
E
F
12345678
A
B
C
D
E
F
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
CALLOUTS
Taps (Pressure, Sampling, Sensor - by letter)
YY
12
B
A
DR1
MU
PG1
MU
DR2
AB
PG2PG3
JR1
JR3
JR4
JR2
JRT
JRP
JL2
JL4
JL1
JL3
JLT
JLP
AR1
BR1
AL2
BL2
X
DR
HL
dL5
aL5
BL4
bL4
AL3
BL3
aL3
bL2
AL1
BL1
aL1
PSW
aR1
aR2
AR2
BR2
bR3
aR4
Y
HR
AR4
R1
dSW
bR2bR1
PL
PR
Pp1
bL1
PAT
aL2
bL3 aL4
PiL
aR3
dR4
SA5
SA4
SA3
SA2
SA1
SB5
SB4
SB3
SB2
SB1
SP
BPi
dR5
AR3
BR3
R2
R3
APi2
PP2
TT
TP
TLA1
BDr
TLA2 TRA2
TRA1
PSL
APi
ADr
AL4
B
L
L1
S
X
T1
L'L'
B'
A'
BR
BR
MB
MA
MB
A'
B'
T1
A'B'
B
A
T2
X
T2
MA
B
A
X
PTA
Pi8
PSA
PG
TOUT
DR1DR2DR3
DR4
DR5
DR6
Pi3
PIN
PEU
Pi1
Pi2
C/V
JPi
Pi5
PAC
R1
S
R2
X1
X2
M3
X3
A1
M1
A2
M2
R1
A3
(1) MOTOR GP
SWING
123-1998
STICK CYLINDER
(3) MOTOR GP
TRAVEL(LEFT)
137-3791
(10) SWIVEL GP
137-3796
(7) VALVE GP
TRAVEL
COUNTERBALANCE(RIGHT)
111-9993
BUCKET CYLINDER
BOOM CYLINDER
(11) SWITCH AS-PRESSURE
(BOOM RAISE)
106-0180
(54) SENSOR
AS PRESSURE
106-0178
(2) MOTOR GP
SWING
147-5789
(4) MOTOR GP
TRAVEL(RIGHT)
137-3791
(6) VALVE GP
TRAVEL
COUNTERBALANCE(LEFT)
111-9993
(62) MOTOR GP
PISTON
155-9107
(63) TANKER
AND FILTER GP
HYDRAULIC
126-2111
(64) VALVE GP
RELIEF
143-8144
(61) RADIATOR GP
139-8823
(60) COOLER GP
ENGINE OIL
115-2990
(57) VALVE GP
CHECK
185-0384
(59) FILTER GP
OIL
126-2112
(58) VALVE AS CHECK
(COOLER BYEPASS)
123-2505
(41) FILTER GP
OIL
4I-3741
(43) ACCUMULATOR GP
HYDRAULIC UNCHARGED
087-4456
(44) VALVE GP
PILOT
123-2146
(39) VALVE GP
RELIEF
(NEGATIVE FLOW CONTROL)
122-7750
(30) VALVE GP
LOAD CONTROL
(STICK LOWERING CONTROL)
202-9264
(14) VALVE GP
MAIN CONTROL
122-7760
(25) VALVE GP
CHECK
AND RELIEF
155-3872
(31) VALVE GP
RELIEF
177-2708
(40) VALVE GP
PILOT
123-2147
(42) VALVE GP
SELECTOR
123-2147
(45) FILTER GP
OIL HYDRAULIC OIL
126-2075
(32) VALVE GP
GENERATION
140-0672
(34) VALVE GP
PRESSURE
CONTROL
122-7708
(29) VALVE GP
LOAD
CONTROL
156-0844
(19) VALVE GP
PILOT
123-2148
(20) VALVE GP
LOAD
CONTROL
156-0844
(21) VALVE GP
LOAD
CONTROL
(STICK
LOWERING
CONTROL)
202-9264
(13) VALVE GP
RELIEF
(STICK CYLINDER ROD END)
156-0844
(15) SWITCH AS
PRESSURE(IMPLEMENT/SWING)
122-7760
(17) VALVE GP
RELIEF(BOOM CYLINDER
HEAD END)
177-2708
(38) VALVE GP
RELIEF (BOOM
CYLINDER ROD
END)
177-2708
(36) VALVE GP
RELIEF(BUCKET CYLINDER HEAD END)
177-2708
(51) MANIFOLD GP
CONTROL
111-9950
(50) VALVE GP
RELIEF(PILOT)
143-8145
(46) VALVE GP
SOLENOID
(FINE CONTROL)
121-1491
(47) VALVE GP
SOLENOID
(TRAVEL SPEED)
121-1491
(48) VALVE GP
SOLENOID
(SWING)
121-1491
(Stick Cyliner Rod End)(Stick Cyliner Rod End)(Stick Cyliner Rod End)
STICK DRIFT
REDUCTION VALVE
BOOM DRIFT
REDUCTION VALVE
PILOT PUMP
COOLING PUMP
UPPER PUMP
LOWER PUMP
PROPORTIONAL
REDUCING VALVE
(POWERSHIFT)
LEFT TRAVEL
CONTROL
VALVE
STRAIGHT
TRAVEL
CONTROL
VALVE
SWING
CONTROL
VALVE
LOGIC
VALVE
VALVE
(REGENERATION
AND CUT)
RIGHT
TRAVEL
CONTROL
VALVE
ATCH
CONTROL
VALVE
BUCKET
CONTROL
VALVE
(37) VALVE GP
RELIEF(BUCKET CYLINDER ROD END)
177-2708
MACHINE COMPONENT LOCATIONS
63
61
60
59
54
45
41
32
19
14
10
7
6
4
3
2
1
VIEW ALL CALLOUTS
MAIN CONTROL VALVE
AL4
BL3 BL2
BL1
BL4
AL3
AL2
AL1
X
PTA
PSW
PiH
BR1
BR2
AR3
AR4
AR1
AR2
BR3
Y
38
37
36
31
30
29
25 21
20
17
13
VIEW ALL CALLOUTS
PILOT OIL MANIFOLD
PG
PSA
T-OUT
DR6
DR5
DR4
Pi8
Pi3
Pi2
Pi1
PAC
DR3
DR2
DR1
Pi5
JPi
C/V
PEPU
P-IN
50
48
47
46
43
VIEW ALL CALLOUTS
