RENR7218
30 Page
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)
System 16 Prime : One Way / Two Pump / Joystick Switch
RENR7218
July 2006
345C Excavator
Hydraulic System - Attachment
GPH1-UP
GCL1-UP
GJR1-UP
ELS1-UP
LYS1-UP
©
2006 Caterpillar
All Rights Reserved
Printed in U.S.A.
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
Description
Part
Number
Machine
Location
Schematic
Location
Pump Gp - Auxilliary 136-8899 1 B-3
Tee Assembly 164-5550 2 D-3
Valve Gp - Boom Pilot 119-5219 3 B-1
Valve Gp - Boom Pilot Solenoid 121-9102 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-3
Accumulator Gp - Pilot Manifold Note B 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 B 23 F-6
Filter Gp - Case Drain Note B 24 A-5
Filter Gp - Pilot Note B 25 A-4
Filter Gp - Return Oil Note B 26 A-7
Motor Gp - Cooling Fan Note B 27 A-7
Motor Gp - Left Swing Note B 28 F-8
Motor Gp - Left Travel Note B 29 F-5
Motor Gp - Right Swing Note B 30 F-7
Motor Gp - Right Travel Note B 31 F-4
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 - Heavy Lift Solenoid Note B 38 B-4
Valve Gp - Left Fine Swing Motor Note B 39 E-8
Valve Gp - Left Travel / Brake Note B 40 E-5
Valve Gp - LH Pilot Control (Stick/Swing) Note B 41 C-8
Valve Gp - Main Control Note B 42 D-1 thru D-6
Valve Gp - Pilot Manifold Note B 43 B-5 thru B-6
Valve Gp - Pilot Travel Note B 44 D-7 , D-8
Valve Gp - Power Shift Control Solenoid Note B 45 B-2
Valve Gp - RH Pilot Control (Bucket/Boom) Note B 46 C-7
Valve Gp - Right Travel / Brake Note B 47 E-4
Valve Gp - Slow Return Check Note B 48 B-8
Note A: Refer to parts manual for specific cylinder information.
Component Locations
System 16 Attachment
Standard 345C
Note B: Part numbers are located on the main Hydraulic System Schematic according to
the effectivity of the machine.
8 41 20
2144
46 21 22
23
34
30
39
28
3524
25
26
14 31
47
40
29
48
37
5
9
3
6
2
42
19
3836
27
32
2321
24
25
31
47
29
40
19
36
3
35
4338
14
32
27
28
30
39
4420834
46
41
48
37
42
6
9
52
7
33
BB
DD
CC
FF
EE
SOS
AA
45
22
26
33
33
45
45
7
7
43
NEGATIVE FLOW CONTROL
MACHINE COMPONENT LOCATIONS
PUMP & FILTER GROUP
RENR7218
30 Page, Color 2
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 #: 239-8957 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
Components by number
YY
52
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations
VALVE GP
NEGATIVE FLOW
CONTROL SOLENOID
171-0188
VALVE GP
CHECK
239-9036
FILTER GP
DRAIN RETURN
TANK GP
HYDRAULIC
FILTER GP
RETURN
VALVE GP
PILOT
MANIFOLD
ACCUMULATOR GP
PILOT MANIFOLD
PUMP GP
AUXILLIARY
136-8899
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
BUCKET CYLINDER
BOOM
CYLINDER
BOOM
CYLINDER
STICK CYLINDER
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
PC
PG
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
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
VALVE GP
BOOM PILOT
119-5219
VALVE GP
FLOW CONTROL
BOOM
4I-7836
VALVE GP
BOOM PILOT
SOLENOID
121-6303
VALVE GP
PILOT
SHUTTLE
185-0462
VALVE GP
MAIN CONTROL
MOTOR GP
RIGHT TRAVEL
VALVE GP
LEFT
TRAVEL/BRAKE
VALVE GP
RIGHT
TRAVEL/BRAKE
SWIVEL GP
MOTOR GP
LEFT TRAVEL
MOTOR GP
LEFT SWING
VALVE GP
LEFT FINE SWING MOTOR
MOTOR GP
RIGHT SWING
VALVE GP
PILOT CONTROL
TRAVEL
BLOCK
VALVE GP
LH PILOT CONTROL
STICK/SWING
VALVE GP
RH PILOT CONTROL
BUCKET/BOOM
MOTOR GP
COOLING FAN
VALVE GP
CHECK
SLOW RETURN
VALVE GP
CHECK COOLER
BYPASS
FILTER GP
CASE DRAIN
VALVE GP
BOOM/SWING
PRIORITY
FILTER GP
PILOT
VALVE GP
HEAVY LIFT
SOLENOID
aL2
VALVE GP
ATTACHMENT
RELIEF
239-9102
FINE
SWING
PUMP GP
DRIVE/IDLER
& PILOT
VALVE GP
POWER SHIFT
CONTROL SOL
PUMP GP
COOLING FAN
