SENR1990-03
July 2012
Third Pedal
345B and 345B II Excavators
Hydraulic System - Attachment
345B:
4SS1-UP
5WS1-UP
6XS1-UP
9GS1-UP
2NW1-UP
345B II:
ALB1-UP
ALD1-UP
AKJ1-UP
AGS1-UP
DCW1-UP
AKX1-UP
Printed in U.S.A.© 2012 Caterpillar, All Rights Reserved
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)
PUMP
(2 - SECTION)
SPRING
(ADJUSTABLE)
VARIABILITY LINE RESTRICTION
(VARIABLE)
PRESSURE
COMPENSATION
PUMP
(VARIABLE & PRESSURE
COMPENSATED)
MEASUREMENT
PRESSURE TEMPERATURE FLOW
ROTATING SHAFTS
UNIDIRECTIONAL BIDIRECTIONAL
PUSH - PULL LEVER PEDALGENERAL MANUAL PUSH BUTTON SPRING
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
UNIDIRECTIONAL
BIDIRECTIONAL
VALVE ENVELOPES VALVE PORTS
FLUID CONDITIONERPUMP OR MOTOR
FLUID POWER SYMBOLS
UNIDIRECTIONAL
BIDIRECTIONAL
RELEASED PRESSURE
EXTERNAL RETURN INTERNAL RETURN
REMOTE SUPPLY PRESSURE
SIMPLIFIED
HYDRAULIC PUMPS
ACCUMULATORS
SPRING LOADED GAS CHARGED
SOLENOID
OR MANUAL
SOLENOID
& PILOT
SOLENOID &
PILOT OR MANUAL
SOLENOID SERVO THERMAL DETENT
HYDRAULIC & PNEUMATIC CYLINDERS
DOUBLE ACTINGSINGLE ACTING
BASIC
SYMBOL
SPRING
LOADED
CHECK VALVES
2 POSITION
INFINITE
POSITIONING
FLOW IN ONE
DIRECTION
FLOW IN
EITHER
DIRECTION
3 POSITION
CROSS
FLOW
PARALLEL
FLOW
INTERNAL PASSAGEWAYS
NORMAL POSITION
AB
PT
AB
PT
SHIFTED POSITION INFINITE POSITION
CONTROL VALVES
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOT
CONTROLLED
MAIN AUX
LINE RESTRICTION
(VARIABLE & PRESSURE
COMPENSATED)
MANUAL CONTROL SYMBOLS
HYDRAULIC MOTORS
FLUID STORAGE RESERVOIRS
CROSSING & JOINING LINES
VALVES
PILOT CONTROL SYMBOLS
COMBINATION CONTROLS
BASIC COMPONENT SYMBOLS
ENERGY TRIANGLES
HYDRAULIC PNEUMATIC
INTERNAL
SUPPLY PRESSURE
COMPLETE
FIXED
DISPLACEMENT
VARIABLE DISPLACEMENT
NON-COMPENSATED
HYDRAULIC SYMBOLS (ELECTRICAL)
ELECTRICAL SYMBOLS TABLE
325-AG135 PK-14
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
WIRE
WIRE
(EXAMPLE VALVE)
CURRENT STANDARD
TRANSDUCER
(FLUID)
M
ELECTRIC MOTORTRANSDUCER
(GAS / AIR)
G
GENERATOR
PRESSURE SWITCH ELECTRICAL WIREPRESSURE SWITCH
(ADJUSTABLE)
TEMPERATURE
SWITCH
PRESSURE
SWITCH
TEMPERATURE
SWITCH
LEVEL
SWITCH
FLOW
SWITCH
ELECTRICAL SYMBOLS (ELECTRICAL)
A
CIRCUIT NUMBER
IDENTIFICATION
WIRE
COLOR
WIRE GAUGE
T
SENR1990-03
24 Page, (Dimensions: 34 inches x 28 inches)
12
Component
Schematic
Location Location
Valve Gp - Pilot B-7 1
Valve Gp - Logic B-7 2
Component Location
Machine
SENR1990-03
24 Page, (Dimensions: 34 inches x 28 inches)
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: THIRD PEDAL
SCHEMATIC PART NUMBER: 123-2551
MEDIA NUMBER: SENR1990-03
THIS SCHEMATIC IS FOR THE 345B AND 345B II EXCAVATORS HYDRAULIC SYSTEM
A
B
C
D
E
F
1234567
A
B
C
D
E
F
1234567
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Components (By number)
52
P
M
BA
DR1
MU
SWING
MOTOR
PG1
SWING
MOTOR
MU
DR2
AB
PG2 PG3
(WATER)
B
STICK
SWING
BOOMBUCKET
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
aR2 aR1 PLPR
PP1
aL1
PAT
aL2 aL3 bL4
BOOM(1)
BUCKETATCH
TRAVEL(R)
PiL
bR3bR4
SA5
SA4
SA3
SA2
SA1
SB5
SB4
SB3
SB2
SB1
SP
(F)
BPi
(F)
(B)
(R)
(L)
SWING
(B)
L
L1
S
X
(40 MESH)
ST
(40 MESH)
(UP)
(CLOSE)
(BACK)
(BACK)
(R)
(OUT)
(UP)
(OPEN)
(DOWN)
(IN,OUT,DOWN)
dR5
(FWD)
(FWD)
(L)
AR3
J
R1
S
R2
X1
X2
M3
X3
A1
M1
A2
M2
R1
A3
T1
RIGHT
L'L'
(IN)
BR3
R2
B' A'
BR
R3
BR
MB
MA
MB
A'B'
T1
LEFT
APi2
A'
PP2
Pi8
PSA
PG
B'
STICK(1)
STICK(2)
BOOM(2)
TRAVEL(L)
TOUT
DR1DR2DR3
B
A
DR4
DR5
DR6
(1/2)
Pi3
(TRAVEL)
(SWING)
PIN
PEPU
(PUMP)
Pi1
Pi2C/V
TRACK
JPi
Pi5
(RELIEF)
T2
PTA
X
T2
MA
(OIL)
P
T
(1) VALVE GP
PILOT
R
TT
F
ATR1
TP
TRAVEL(R)
PAC
TRAVEL(L)
CTR1
CTR3
TLA2
BDr
TR3
TR4
TLA1
CTR4
TRA1
TR1
TRA2
B
PSL
A
X
TR2
(40 MESH)
CTR2
ATR2
APi
ADr
AL4
(2) VALVE GP
LOGIC
