RENR7391-01
30 Page: (Dimensions: 39 inches x 28 inches)
Fine Filtration
RENR7391-01
September 2006
SPC1-UP
GPH1-UP
GCL1-UP
ELS1-UP
LYS1-UP
©
2005 Caterpillar
All Rights Reserved
Printed in U.S.A.
345C Excavator
Hydraulic System - Attachment
33
BB
DD
CC
SOS
AA
Last Modified: 10/15/2003
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)
Last Modified: 05/10/2004
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
PUMP & FILTER GROUP
1
40 20
2143
44 21 22
23
34
29
38
31
3524
25
26
33 30
45
39
28
46
37
19
42
36
41
27
32
2321
24
25
30
45
28
39
26 35
42
19
36
33
32
27
29
31
38
43
2034
44
40
46
37
41
22
MACHINE COMPONENT LOCATIONS
1
Description
Part
Number
Machine
Location
Schematic
Location
Filter Gp - Fine Filtration 250-0729 1 B-1
Accumulator Gp - Pilot Manifold Note B 19 B-5
Cylinder Gp - Boom Note A 21 F-2
Cylinder Gp - Bucket Note A 22 F-3
Cylinder Gp - Stick Note B 23 E-8
Filter Gp - Drain Return Note B 24 A-6
Filter Gp - Pilot Note B 25 A-4
Filter Gp - Return Oil 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-6
Motor Gp - Right Travel
Note B 30 F-4
Motor Gp - Swing Left
Note B 31 F-7
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-5
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-7
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
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
SOS Hydraulic Oil Sampling Port A-4
RENR7391-01
30 Page: (Dimensions: 39 inches x 28 inches)
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
DRAIN / RETURN LINE
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
PILOT PUMP OUTPUT
SUPPLY LINE
DRIVE PUMP OUTPUT
IDLER PUMP
POWER SHIFT CONTROL CIRCUIT
COOLING FAN PUMP
ATTACHMENT CONTROL CIRCUIT
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
LEFT TRAVEL CONTROL & LEFT TRAVEL MOTOR CIRCUIT
SWING CONTROL & SWING MOTOR CIRCUIT
SWING BRAKES
1
3
4
5
6
7
8
A
C
D
E
F
1
23
4
56
7
8
A
B
C
D
E
F
B
M
BR1
BUCKET CYLINDER
BOOM
CYLINDER
BOOM
CYLINDER
STICK CYLINDER
PG2
PB2
DE2
B2
A2
PA2
M2
DB2
PG1
PA1
M1
DB1
B
A
X
BA
B
A
AG
AGBG
BG
T2
T2
T1
T1
BR
X
B
A
L
BR3 AR3
AR2 BR2
AL3BL3 BL4 AL4
TRAVEL(R)TRAVEL(L)
SWINGSTICK
OUT IN R L
TP
TT
BACK FWD FWD
T2T1 T3 T4
BACK
JLP
JLT
JL1 JL3 JL2 JL4
BOOMBUCKET
OPEN CLOSE UP
JR4 JR2 JR3 JR1
JRP
JRT
bR1 aR1 aL1 bL1
aR2
bR2
bR3aR3
bL3
bL4
aL4
L2
L3
A
B
µµ
µ
DOWN
Pi1P2 P-IN PSA2 DR1
T-OUT2 DR2
DR3
DR4
Pi2 DR5
DR6T-OUT1
P1 P2
T
B1
A1
B2 A2
P1
PSA1
T
OUT
8
6
5
NO.1
(TRAVEL)
NO.2
(SWING)
NO.3
(LOCK)
A4
B1 Dr1 Di PS2 PB
Pi2
B
D0
a2
a5
a3
A2
a1
a4
A1
PSV
IN
1
7
LL1
X
PR
PL
BOOM(1) STICK(2)BUCKETATCH
HL
aL5
Dr
R2
X
dL5(DOWN)
BPiBDr
(UP)(CLOSE)
AL2BL2
aL2PAT
(OPEN)bL2
(B) (F)
PTAPSW
(BACK)
aL4
(IN)
CV1
CV2
A
MU
(OUT)
bL1
BL1
AL1
bL3
BL3 AL3 BL4
AL4
TRAVEL(R)
TRAVEL(L)SWING
Pp1
Pi1
(FWD)
dST1
(BACK)(F)(B)(R)
(FWD)
(L)
(R) (L)
dSWPiL
(OUT)
Pp2
PiH
MU1
aR3
BR2
AR2
bR2
BR1
AR1
bR1
aR2
aR1
PR
PL aL1 aL3
bL4
STICK(1)BOOM(2)
R1
Y
HR
AR4
R3
dR4 (IN)
APiADr
APi2
dR5
A A
MU2
MU1
CV CV
AR3BR3aR4
bR3
AR1
AL1 BL1
PS1
PB1
PUMP GP
COOLING FAN
VALVE GP
BOOM/SWING
PRIORITY
PUMP GP
DRIVE/IDLER
& PILOT
FILTER GP
PILOT
PCPG
VALVE GP
PILOT
MANIFOLD
TANK GP
HYDRAULIC
FILTER GP
RETURN
ACCUMULATOR GP
PILOT MANIFOLD
FILTER GP
DRAIN RETURN
MOTOR GP
COOLING FAN
VALVE GP
CHECK COOLER
BYPASS
VALVE GP
CHECK
SLOW RETURN
VALVE GP
LH PILOT CONTROL
STICK/SWING
VALVE GP
RH PILOT CONTROL
BUCKET/BOOM
VALVE GP
PILOT CONTROL
TRAVEL
VALVE GP
LEFT SWING MOTOR
MOTOR GP
LEFT TRAVEL
VALVE GP
LEFT
TRAVEL/BRAKE
MOTOR GP
LEFT SWING
MOTOR GP
RIGHT SWING
MOTOR GP
RIGHT TRAVEL
VALVE GP
RIGHT
TRAVEL/BRAKE
SWIVEL GP
VALVE GP
MAIN CONTROL
(UP)
aL3
FILTER GP
CASE DRAIN
FILTER GP
FINE FILTRATION
250-0729
DR
DR1
THIS SCHEMATIC IS FOR THE 345C (ATTACHMENT)
Components are shown installed on a fully operable machine with the key and engine off and transmission
shifter in neutral.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations
PART #: 253-0013 (V) CHG00
BB
CC
DD
SOS
AA
µµµ µµµµ µ
µ
MU2
BR
L
B
A
DE1
B1
A1
S
2
