Printed in U.S.A.© 2010 Caterpillar, All Rights Reserved
Pin Grabber Coupler Circuit
UENR1751
November 2010
345D Excavator
Hydraulic System - Attachment
BYC1-UP
RAE1-UP
YEE1-UP
NEG1-UP
EEH1-UP
RAJ1-UP
PBT1-UP
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
UENR1751
30 Page, (Dimensions: 39 inches x 28 inches)
COMPONENT LOCATIONS
PUMPS AND FILTERS
31
31
1
1
24
3
24
2
19
20
15
15
24
24
11
12
11
12
18
17
18
17 6
6
10
10
27
27
25
1913
13
38
14
21
22
23
23
30 34
30 34 33
33
8
8
5
5
7
5
6
BB
FF
DD CC AA SOS EE
7
7
15
26
26
13
MAIN CONTROL / PILOT
1
26
36
37
21
32
19
31
AL1AL2
BL1BL2BL3
AL3
AL4
BL4
X
HEAVY LIFT
40
1
32
31
Tap Locations
Pressure and Sampling
Tap
Number
Description
Schematic
Location
AA Pump Pressure (Right Bank) B-3
BB Pump Pressure (Left Bank) A-3
CC Power Shift Pressure A-3
DD Pump Case drain A-2
EE Pilot Pressure B-1
FF Pump Pilot Pressure D-3
SOS SOS (Scheduled Oil Sampling) B-1
Description
Part
Number
Machine
Location
Schematic
Location
Accumulator Gp - Pilot Man. 164-6981 1 C-1
Cylinder Gp - Boom Note A 2 F-3
Cylinder Gp - Bucket Note A 3 F-4
Cylinder Gp - Stick Note A 4 E-4
Filter Gp - Case Drain 289-8194 5 B-2
Filter Gp - Oil, Drain Return 289-8194 6 C-2
Filter Gp - Pilot 158-8987 7 B-1
Filter Gp - Oil, Return 188-4145 8 C-1, C-2
Motor Gp - Cooling Fan 295-9429 10 A-4
Motor Gp - Left Travel 232-6180 11 B-8
Motor Gp - Right Travel 232-6180 12 B-7
Motor Gp - Swing 225-4506 13 A-5, B-6
Pump Gp - Cooling Fan 295-9426 14 A
-3
Pump Gp - Drive, Idler, Pilot 295-9663 15 A-2
Sensor Gp - Pressure, Bm Dn Pilot 297-4483 16 C-4
Sensor Gp - Pressure, Pump 260-2180 17 A-3
Sensor Gp - Pressure, Pump 260-2180 18 B-3
Sensor Gp - Pressure, Boom Cyl. Head 221-8859 F-3
Switch As - Pressure, Swing Pilot 309-5769 E-8
Switch As - Press., Bm Up/Stck In Pilot 309-5769 E-7
Switch As - Press., Implmnt, Trvl Pilot 106-0179 F-7, F-8
Swivel Gp 225-4547 A-7
Valve Gp - Solenoid, Neg. Flow Control 171-0188 D-2
Valve Gp - Boom
Down Relief 310-0147 E-3
Valve Gp - Priority, Boom/Stick 310-0210 E-7
Valve Gp - Check, Clr Bypass 123-2505 B-4
Valve Gp - Check, Slow Return 285-1715 B-5
Valve Gp - Left, Travel Counterbalance 266-7843 A-8
Valve Gp - LH Plt Cntrl, Stck/Swng 297-0533 F-6
Valve Gp - Main Control 323-7681 C-3 To D-8
Manifold Gp - Control, Pilot Oil Supply 215-5037 C-2
Valve Gp - Plt Contr. Travel 310-0415 F-7
Valve Gp - RH Plt Cntrl, Bckt/Bm 297-0532 F-6
Valve Gp - Right, Travel Cntrbalance 266-7843 A-7
Valve Gp - Shuttle, Stick Pilot 123-2430 E-7
Valve Gp - Shuttle,
Swing Pilot 123-2430 E-8
- Swing Cushion (Fine Swing) 295-9423
A-6
Valve Gp - Sol. / Manifold, Quick Cplr 328-2035 E-4
NOTE A : CHECK PARTS MANUAL FOR IDENTIFICATION NUMBERS
Component Locations
Pin Grabber Coupler Circuit
STICK(2) BUCKET TRAVEL(R) TRAVEL(L) STICK(1)
BOOM(1) ATCH STR TRAVEL SWING BOOM(2)
AR2AR1 BR3
AR4
BR1 BR2
AR3
PiH
Y
PTA PSW
Valve Gp - Swing Cushion
295-9422
16
16
19
20
21
22
23
25
26
27
28
29
30
31
32
33
34
35
36
37
38
41
26
24
28
28
Connector As - Orifice 148-8336 39 E-8
39
Valve Gp - Solenoid (Heavy Lift) 121-6303 B-5
40
PIN GRABBER COUPLER CIRCUIT
41
DRAIN / RETURN LINE
LINES GROUP COLOR DESCRIPTIONS
DRIVE PUMP OUTPUT
IDLER PUMP OUTPUT
POWER SHIFT CONTROL CIRCUIT
PILOT PUMP OUTPUT
HYDRAULIC OIL COOLING PUMP OUTPUT
PIN GRABBER COUPLER CONTROL CIRCUIT
SUPPLY LINE
BUCKET CONTROL AND BUCKET CYLINDER CIRCUIT
RIGHT TRAVEL CONTROL AND RIGHT TRAVEL MOTOR CIRCUIT
TRAVEL SPEED CONTROL CIRCUIT
STICK CONTROL AND STICK CYLINDER CIRCUIT
BOOM CONTROL AND BOOM CYLINDER CIRCUIT
HEAVY LIFT CONTROL CIRCUIT
LEFT TRAVEL CONTROL AND LEFT TRAVEL MOTOR CIRCUIT
SWING CONTROL AND SWING MOTOR CIRCUIT
SWING BRAKE CONTROL CIRCUIT
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
UENR1751
30 Page, (Dimensions: 39 inches x 28 inches)
THIS SCHEMATIC IS FOR THE 345D EXCAVATOR HYDRAULIC SYSTEM
PART NUMBER: 297-0246, CHANGE: 02, VERSION: HE
Components are shown installed on a fully operable machine.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.
THIS SCHEMATIC IS FOR THE 345D EXCAVATOR
HYDRAULIC SYSTEM
ATTACHMENT: PIN GRABBER COUPLER CIRCUIT
PART NUMBER: 344-4215, CHANGE: 00, VERSION: HE
Components are shown installed on a fully operable machine.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations.
12345678
A
B
C
D
E
F
12345678
A
B
C
D
E
F
(2) CYLINDER GP - BOOM
(4) CYLINDER GP - STICK
(3) CYLINDER GP - BUCKET
CV
CH CR
Pi DR
T
TRAVEL MOTOR (LEFT)
TRAVEL MOTOR (RIGHT)
X
BA
BA
AG AGBG BG
T2
T2
T1
T1
BR
BR
X
B
A
L
LB
A
(23) SWIVEL GP
225-4547
DR3 DR4
DR5 T-OUT1
DR6
DR2T-OUT2PSA1
DR1
PSA2P-INP2
P1
1
2
3
4
5
6
7
SDr HL
Dr
XR2
Pp1
Pp2
bR4 SPi2 SDr2
dSW
dST1 PiH
Pi2
P1 P2
A1B1 A2B2
TP
TT
JLP
JRP
JLT
JRT
PSW PTA
R3 YR1
A
B
A2 B2
MU1
MU2
PG2
DB2
DB1
PG1
DE2
Pi1
aL4
T
(1) ACCUMULATOR GP -
PILOT MANIFOLD
164-6981
A4B1
Dr1
Di
PS2
PB
D0
PS1
S
L1
L
X
B
a2
a5
a3
PSV
TP
A1
A1 A2 A3 A4 A5 A6 A8A7
B1
B2
B3
B4
B5
B6
B7
B8
JL1 JL3 JL2 JL4 JR4 JR2 JR3 JR1
PAT
aL2
BL2AL2
bL2
A1 B1
A2
A1
a1
a4
AL4
BL4 aL5SPi
T
OUT
PGPC
IN
SWING MOTOR
AG1
BG1
AG2
BG2
1
2
3
4
56
1
2
3
4
56
T1 T2 T3 T4
STICK
SWING BUCKET
BOOM
(OUT) (IN) (R) (L) (OPEN)(CLOSE) (DOWN) (UP)
DE1
Pi1
Pi2
SWING MOTOR
HR
AR4
B1
A2
B2
μμμμ
TRAVEL(L)
TRAVEL(R)
(BACK)
(FWD)
(FWD)(BACK)
AR1BR1 AL1 BL1
PR
PL
PLPR
BR2AR2
BR3
aR4
aR3
AR3 BR2 AR2
bR2
BR1
AR1
bR1
bL3
bL1
BL1
AL1
AL3BL3
bR3
bR1
aR4bL3 bL4 aL3 aR3 bR2 bR3 aR2
aR1 aL1 bL1
aR2 aR1 aL1
aL3
bL5
bL5 PiL
PiL
DR
DR1L2 L3
A
B
AL3BL3
AR3BR3
TRAVEL(R)
TRAVEL(L)
STICK(1)
SWING
ATCH
BOOM(2)
(UP)
(DOWN)
BUCKET
(OPEN)
(CLOSE)
(BACK)
(FWD)
BOOM(1)
(IN)
(OUT)
(FWD)
(BACK)
STICK(2)
(IN)
(OUT)
(R)
(L)
(UP)
NO.1
(TRAVEL)
NO.2
(SWING)
NO.3
(LOCK)
(15) PUMP GP -
DRIVE/IDLER PILOT
295-9663
(14) PUMP GP -
COOLING FAN
295-9426
(5) FILTER GP - OIL
(CASE DRAIN)
289-8194
(6) FILTER GP - OIL
DRAIN RETURN
289-8194
(8) FILTER GP -
OIL, RETURN
188-4145
(32) MANIFOLD GP
CONTROL
(PILOT OIL SUPPLY)
215-5037
(10) MOTOR GP - COOLING FAN
295-9429
(13) MOTOR GP -
SWING
225-4506
(28) VALVE GP - CHECK
(SLOW RETURN)
285-1715
(27) VALVE GP - CHECK
(COOLER BYPASS)
123-2505
(13) MOTOR GP - SWING
225-4506
(38) VALVE GP -
SWING CUSHION: 295-9422
SWING CUSHION (FINE SWING): 295-9423
(35) VALVE GP - RIGHT
TRAVEL COUNTERBALANCE
266-7843
(12) MOTOR GP - RIGHT TRAVEL
232-6180
(11) MOTOR GP - LEFT TRAVEL
232-6180
(29) VALVE GP - LEFT
TRAVEL COUNTERBALANCE
266-7843
(36) VALVE GP -
SHUTTLE
(BOOM / STICK)
123-2430
(26) VALVE GP -
BOOM AND STICK PRIORITY
310-0210
(33) VALVE GP - PILOT (TRAVEL)
310-0415
(30) VALVE GP -
LH PILOT CONTROL
(STICK/SWING)
297-0533
(34) VALVE GP -
RH PILOT CONTROL (BUCKET/BOOM)
297-0532
(22) SWITCH AS - PRESSURE
(PILOT HYDRAULIC OIL)
106-0179
(31) VALVE GP -
MAIN CONTROL
323-7681
BB
AA
(17) SENSOR AS -
PRESSURE
(PUMP
CONTROL)
260-2180
(18) SENSOR AS -
PRESSURE
(PUMP CONTROL)
260-2180
CC
DD
SOS
EE
FF
(24) VALVE GP - SOLENOID
(NEGATIVE FLOW CONTROL)
171-0188
PILOT VALVE GP -
BOOM DOWN RELIEF
310-0147
(20) SWITCH AS -
PRESSURE (SWING)
309-5769
(20) SWITCH AS - PRESSURE
(BOOM UP / STICK IN)
309-57693
bL4
(40) VALVE GP -
SOLENOID
(HEAVY LIFT)
121-6303
(16) SENSOR AS - PRESSURE
(BOOM DOWN)
297-4483
(19) SENSOR AS -
PRESSURE
(BOOM CYLINDER)
221-8859
(7) FILTER GP -
PILOT (HYDRAULIC OIL)
158-8987
(37)
VALVE GP
SHUTTLE
SWING PILOT
123-2430
(39) CONNECTOR AS
ORIFICE
148-8336
P
T
C1 C2
UNLOCK
LOCK
(41) VALVE GP -
SOL. / MANIFOLD
QUICK COUPLER
328-2035
