INTERACTIVE SCHEMATIC
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Tap Table
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Electrical Symbols
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EC-C3
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Boom Lowering Control Valve
Hydraulic System (Attachment)
345B and 345B Series II Excavators
©
2001 Caterpillar, All Rights Reserved
Printed in U.S.A.
RENR1907-01
September 2001
CCC1-UP
BFG1-UP
4SS1-UP
7KS1-UP
9GS1-UP
2SW1-UP
COMPONENT LOCATION
Description
Part
Number
Machine
Location
Schematic
Location
Valve Gp - Main Control (Boom Lowering) 239-8977 1 E-3
Valve Gp - Manifold (Boom Lowering) 165-9580 2 D-3
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.
ATTACHMENT: BOOM LOWERING CONTROL VALVE
SCHEMATIC PART NUMBER: 146-1529, CHANGE: 01, VERSION: HE
MEDIA NUMBER: RENR1907-01
THIS SCHEMATIC IS FOR THE 345B AND 345B SERIES II EXCAVATORS
HYDRAULIC SYSTEM
A
B
C
D
E
1234567
A
B
C
D
E
1234567
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
CALLOUTS
Taps (Pressure, Sampling, Sensor - by letter)
YY
(52) VALVE GP - CONTROL
138-1234
Callout Number
(Machine Location from
Component LocationsTable)
Component
Name
Part Number
B A
D R 1
M U
S W I N G
M O T O R
P G 1
S W I N G
M O T O R
M U
D R 2
AB
P G 2 P G 3
( W A T E R )
B
S T I C K
S W I N G
B O O MB U C K E T
J R 1
J R 3
J R 2
J R 4
J R T
J R P
J L 4
J L 2J L 1
J L 3
J L T
J L P
A R 1
B R 1
A L 2B L 2
X
D R
H L
bL 5
a L 5
B L 4
a L 4
A L 3
B L 3bL 3
bL 2
A L 1
B L 1
bL 1
P S W
bR 1
bR 2
A R 2
B R 2
a R 3
a R 4
Y
H R
A R 4
R 1
dS W
a R 2 a R 1 P LP R
P P 1
a L 1
P A T
a L 2 a L 3 bL 4
B O O M ( 1 )
B U C K E TAT C H
T R AV E L (R )
P iL
bR 3dR 4
S A 5
S A 4
S A 3
S A 2
S A 1
S B 5
S B 4
S B 3
S B 2
S B 1
S P
( F )
( F )
( B )
( R )
( L )
S W I N G
( B )
L
L 1
S
X
S T
( U P )
( C L O S E )
( B A C K )
( B A C K )
( R )
( O U T )
( U P )
( O P E N )
( D O W N )
( I N , O U T , D O W N )
dR 5
( F W D )
( F W D )
( L )
D r 1
O W D
X 1X 2D r 2B d1
B d2
AB
CP i2
R I G H T
T
L
A
B
G
G
2 1 5 F
A '
A
B
P i
B '
1
2
T
T
X
B R
A
D r
X
C
A
P i
A R 3
R 1
S
R 2
X 1
X 2
M 3
X 3
A 1
M 1
A 2
M 2
R 1
A 3
) (
) (
) (
) (
( I N )
D r
B R 3
R 2
R 3
X
A P i2
P P 2
C
P i8
P S A
P G
S T I C K ( 1 )
S T I C K ( 2 )
B O O M ( 2 )
T R AV E L (L )
T O U T
D R 1D R 2D R 3
D R 4
D R 5
D R 6
( S L O W )
P i3
( T R A V E L )
( S W I N G )
P I N
P E P U
( P U M P )
P i1
P i2C /V
B R
X
T
T
2
1
B '
B
A
A '
2 1 5 F
G
G
B
A
T R A C K
J P i
P i5
( R E L I E F )
P T A
L E F T
( O I L )
T T
T P
T R A V E L ( R )
P A C
T R A V E L ( L )
T L A 2
T L A 1 T R A 1
T R A 2
P S L
L
P i1
A P i
A D r
A L 4
(1) VALVE GP
MAIN CONTROL
(BOOM LOWERING)
239-8977
(2) VALVE GP
MANIFOLD
(BOOM LOWERING
CONTROL)
165-9580
MACHINE COMPONENT LOCATIONS
2
1
VIEW ALL CALLOUTS
