INTERACTIVE SCHEMATIC
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Hydraulic System - Attachment
345C Excavator
©
2007 Caterpillar, All Rights Reserved
Printed in U.S.A.
RENR7125-02
March 2007
System 3: One-Way / Two Pump Flow / Foot Switch
TBA1-UP
ESD1-UP
WDE1-UP
TDG1-UP
TAJ1-UP
S5M1-UP
DHP1-UP
GJR1-UP
PJW1-UP
BWY1-UP
COMPONENT LOCATION
Description
Part
Number
Machine
Location
Schematic
Location
Tee Assembly 164-5550
2
D-3
Valve Gp - Boom Pilot 119-5219
3
B-1
Valve Gp - Boom Pilot Solenoid 121-6303
4
E-2
Valve Gp - Check 239-9036
5
C-3
Valve Gp - Flow Control Boom 4I-7836
6
B-1
Valve Gp - Negative Flow Control Solenoid 171-0188
7
E-1
Valve Gp - Pilot Shuttle 185-0462
8
B-8
Valve Gp - Relief (Attachment) 239-9102 9
E-2
Accumulator Gp - Pilot Manifold 164-6981
19
B-5
Block Note B
20
D-8
Cylinder Gp - Boom Note A
21
E-6
Cylinder Gp - Bucket Note A
22
E-6
Cylinder Gp - Stick Note A
23
F-6
Filter Gp - Case Drain 126-2075
24
A-5
Filter Gp - Pilot 158-8987
25
A-4
Filter Gp - Return Oil 173-3434
26
A-6
Motor Gp - Cooling Fan 242-6904
27
A-7
Motor Gp - Left Swing 225-4506
28
F-8
Motor Gp - Left Travel 232-6180
29
F-5
Motor Gp - Right Swing 225-4506
30
F-7
Motor Gp - Right Travel 232-6180
31
F-4
Pump Gp - Cooling Fan 259-0814
32
B-2
Pump GP - Drive / Idler / Pilot Hydraulic 259-0818
33
B-3
Swivel Gp 225-4547
34
E-4
Tank Gp - Hydraulic Oil 227-0431
35
A-6
Valve Gp - Boom/Swing Priority 232-4102
36
B-4
Valve Gp - Cooler Bypass Check 123-2505
37
B-7
Valve Gp - Heavy Lift Solenoid 121-6303
38
B-4
Valve Gp - Left Fine Swing Motor 116-3420
39
E-8
Valve Gp - Left Travel / Brake 165-9338
40
E-5
Valve Gp - LH Pilot Control (Stick/Swing) 232-4157
41
C-8
Valve Gp - Main Control 230-2760
42
D-4
Valve Gp - Pilot Manifold 215-5037
43
B-6
Valve Gp - Pilot Control Travel 165-9522
44
D-8
Valve Gp - Power Shift Control Solenoid 225-4518
45
B-3
Valve Gp - RH Pilot Control (Bucket/Boom) 232-4158
46
C-7
Valve Gp - Right Travel / Brake 165-9338
47
E-4
Valve Gp - Slow Return Check 185-0384
48
B-8
Note A: Refer to parts manual for specific cylinder information.
System 3 Attachment
Standard 345C
Note B: Part numbers are located on the main Hydraulic System Schematic according to
the effectivity of the machine.
TAP LOCATION
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 Idler Pump Negative Flow Signal Pressure E-1
FF Drive Pump Negative Flow Signal Pressure E-1
SOS Hydraulic Oil Sampling Port A-4
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
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 AND HEAVY LIFT CONTROL CIRCUITS
LEFT TRAVEL CONTROL & LEFT TRAVEL MOTOR CIRCUIT
SWING CONTROL & SWING MOTOR CIRCUIT
SWING BRAKE CONTROL CIRCUIT
THIS SCHEMATIC IS FOR THE 345C (ATTACHMENT)
PART #: 230-2699 HE01
This Attachment Schematic is intended to be used with the Standard Hydraulic Schematic
for the specific machine.
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling,Sensor) by letter
YY
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations
(7) VALVE GP
NEGATIVE FLOW
CONTROL SOLENOID
171-0188
SOS
AA
(5) VALVE GP
CHECK
239-9036
FILTER GP
DRAIN RETURN
(35) TANK GP
HYDRAULIC OIL
227-0431
(26) FILTER GP
RETURN OIL
173-3434
(43) VALVE GP
PILOT
MANIFOLD
215-5037
(19) ACCU. GP
PILOT MANIFOLD
164-6981
EE
FF
BB
CC
DD
1
2
3
4
56
7
8
A
C
D
E
F
1
23
4
56
7
8
A
B
C
D
E
F
B
(22) CYLINDER GP
BUCKET
BOOM
(21) CYLINDER GP
(23) CYLINDER GP
STICK
BOOM(1)
STICK(2)
BUCKET
ATCH
TRAVEL(R)
TRAVEL(L)
SWING
STICK(1)
BOOM(2)
TRAVEL(R)TRAVEL(L)
SWINGSTICK BOOMBUCKET
OUT IN R L OPEN CLOSE DOWN UP
HL
aL5
Dr
R2
X
Pp1
R1
Y
HR
AR4
R3
Pi1P2 P-IN PSA2 DR1
T-OUT2
DR2
DR3
DR4
Pi2
DR5
DR6
T-OUT1
P1 P2
T
B1
A1
B2
A2
A4
B1
Dr1
Di
PS2
PB
Pi2
D0
PS1
Pi1
a2
a5
a3
A2
a1
a4
A1
PSV
P1
PG2
PB2
DE2
B2
A2
PA2
M2
DB2
PG1
PB1
DE1
B1
A1
PA1
M1
DB1
BA
X
BA
B
A
AG
AG
BG
BG
T2
T2
T1
T1
BR
BR
dL5
(DOWN)
BPi
BDr
(UP)
(CLOSE)
AL2
BL2
PAT
(OPEN)
bL2
(F)(B)
PTAPSW
(BACK)
(FWD)
dST1
(BACK)
(F)
(B)
(R)
(FWD)
(L)
(R) (L)
dSW
PiL
(IN)
(OUT)
APi
ADr
(UP)
APi2
dR5
PSA1
X
(IN)
Pp2
T
OUT
IN
TP
TT
BACK FWD FWD
T2T1
T3
T4
BACK
JLP
JLT
JL1 JL3 JL2 JL4 JR4 JR2 JR3 JR1
JRP
JRT
PiH
A1
B1
A2
B2
A3
B3
A4
B4
A5
B5
A6
B6
A7
B7
A8
B8
SINGLE
SINGLE
P
T
A1
A2
B1
B2
A
B
P
T
A
CA
CD
CB1
CB2
(2) TEE AS.
164-5550
8
1
7
6
2
4
L
B
A
A
B
L
P
T
A
S
L1
L
B
X
5
BR3 AR3
AR2 BR2
AL3BL3 BL4 AL4
AR1BR1 AL1 BL1
bR1 aR1
aL1
bL1
aR3 bR2 bR3 aR2aR4 bL3 bL4 aL3
AR3
BR3
aR3
BR2 AR2
bR2
BR1
AR1
bR1
bL1
BL1
AL1
bL3
BL3
AL3
BL4
AL4
bR3 aR2 aR1
PR
PL
aL1 aL3 bL4
PR
PL
bL2
bL2
aR4
dR4
aL4
aL4
NO.1
(TRAVEL)
NO.2
(SWING)
NO.3
(LOCK)
dR4
µµµ µ
µµµ µ µµµ µ
DR
DR1
L2
L3
A
B
(3) VALVE GP
BOOM PILOT
119-5219
(6) VALVE GP
FLOW CONTROL
BOOM
4I-7836
(4) VALVE GP
BOOM PILOT
SOLENOID
121-6303
(8) VALVE GP
PILOT
SHUTTLE
185-0462
(42) VALVE GP
MAIN CONTROL
230-2760
(31) MOTOR GP
RIGHT TRAVEL
232-6180
(40) VALVE GP
LEFT
TRAVEL/BRAKE
165-9338
(47) VALVE GP
RIGHT
TRAVEL/BRAKE
165-9338
(34) SWIVEL GP
225-4547
(29) MOTOR GP
LEFT TRAVEL
232-6180
(28) MOTOR GP
LEFT SWING
225-4506
(39) VALVE GP
LEFT FINE SWING MOTOR
116-3420
(30) MOTOR GP
RIGHT SWING
225-4506
(44) VALVE GP
PILOT CONTROL
TRAVEL
165-9522
(20) BLOCK
(41) VALVE GP
LH PILOT CONTROL
STICK/SWING
232-4157
(46) VALVE GP
RH PILOT CONTROL
BUCKET/BOOM
232-4158
(27) MOTOR GP
COOLING FAN
242-6904
(48) VALVE GP
CHECK
SLOW RETURN
185-0384
(37) VALVE GP
CHECK COOLER
BYPASS
123-2505
(24) FILTER GP
CASE DRAIN
126-2075
(36) VALVE GP
BOOM/SWING PRIORITY
232-4102
(25) FILTER GP
PILOT
158-8987
(38) VALVE GP
HEAVY LIFT SOL
121-6303
aL2
(9) VALVE GP
ATTACHMENT
RELIEF
239-9102
FINE
SWING
(33) PUMP GP
DRIVE/IDLER/PILOT
HYDRAULIC
259-0818
(45) VALVE GP
POWER SHIFT
CONTROL SOL
225-4518
(32) PUMP GP
COOLING FAN
259-0814
PC
PG
DRIVE
IDLER
PILOT
NEGATIVE FLOW CONTROL
FF
EE
7
VIEW ALL CALLOUTS

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