©
2003 Caterpillar
All Rights Reserved
Printed in U.S.A.
RENR1066-01
December 2003
345B Excavator
Super Long Demolition
2SW1-UP
Hydraulic System - Attachment
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
PEDAL
GENERAL 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
1
2
3
4
5
6
7
8
BA
ls T
p2
p1
TT
TP
P
Dr
BA
DR1
MU
PG1
MU
DR2
AB
PG2
PG3
B
P
T
LS
M
B
A
AR3
JR1
JR3
JR2
JR4
JRT
JRP
JL4
JL2
JL1
JL3
JLT
JLP
AR1
BR1
AL2BL2
X
DR
HL
bL5
aL5
BL4
aL4
AL3
BL3bL3
bL2
AL1
BL1
bL1
PSW
bR1
bR2
AR2
BR2
aR3
aR4
Y
HR
AR4
R1
dSW
aR2aR1
PLPR
PP1
aL1
PAT
aL2 aL3 bL4
PiL
bR3dR4
SA5
SA4
SA3
SA2
SA1
SB5
SB4
SB3
SB2
SB1
SP
L1
S
X
T
S3
S2S1
P
dR5
L
A
B
G
G
A'
A
B
B'
1
2
T
T
X
BR
AR3
R1
S
R2
X1
X2
M3
X3
A1
M1
A2
M2
R1
A3
BR3
R2
R3
APi2
PP2
Pi8
PSA
PG
TOUT
DR1DR2DR3
DR4
DR5
DR6
Pi3
PIN
PEPU
Pi1
Pi2C/V
BR
X
T
T
2
1
B'
B
A
A'
G
G
B
A
JPi
Pi5
PTA
A
Pp
TT
TP
T
PAC
TLA2
TLA1 TRA1
TRA2
PSL
L
D
C1
AL4
Dr1
OWD
X1
X2
Dr2Bd1
Bd2
AB
C
Dr
T
Pi
A
Dr
X
A
Pi
)(
)(
)(
)(
Dr
X
C
Pi
Item
Component
No.
1
2
3
4
5
6
Valve Group
Check Valve
Fore Cylinder Valve
Valve Group
Check Valve
Valve Group
Standard Components
7
8
Solenoid Valve
Selector Valve
This Attachment Schematic is intended to
be used in conjunction with the Standard
Hydraulic Schematic in this Service Manual.
Hydraulic Schematic
157-2105
PILOT LINE
DRAIN LINE
MAIN CONNECTOR LINE
