KENR9543
May 2009
345C UHD Excavator
Hydraulic System
SCN1-UP
Printed in U.S.A.© 2009 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
KENR9543
30 Page, (Dimensions: 39 inches x 28 inches)
Tap Locations
Standard 345C Component Locations
Description
Part
Number
Machine
Location
Schematic
Location
Accumulator Gp - Hydr., Charged 164-6981 1 A-6
Filter and Valve Gp - Hydr. Oil 158-8987 2 A-5
Filter Gp - Hydr. Oil, Case Drain Return 126-2075 3 A-6, A-7
Filter Gp - Hydr. Oil, Return 173-3434 4 A-7
Manifold Gp - Control, Pilot Oil Supply 215-5037 5 B-6 to B-7
Motor Gp - Swing 334-9975 7 E-7, E-8
Motor Gp - Travel 232-6180 8 F-6, F-7
Pump Gp - Auxiliary 136-8899 9 B-5
Pump Gp -
Drive, Idler,Pilot 322-8732 10 A-4 to B-4
Pump Gp - Hydr. Fan 259-0814 11 B-4
Switch As - Press., Fore-Boom Pilot 309-5795 12 D-1
Switch As - Press., Free Rotate 266-5881 13 E-5
Switch As - Press., Travel 309-5795 14 D-5
Swivel Gp 225-4547 15 E-6
Tee As 164-5550 16 D-5
Valve Gp - Check, Bucket Cylinder 202-6281 17 F-3
Valve Gp - Check, Stick, Fore-Boom 233-7881 18 E-1, E-3
Valve Gp - Check, Supply 239-9036 19 C-5
Valve Gp - Check, Boom Float
, Up 215-4890 20 E-3, E-4
Valve Gp - Check, Cooler 185-0384 21 B-8
Valve Gp - Check, Cooler Bypass 123-2505 22 B-7
Valve Gp - Check, E-CV1, E-CV2, E-CV3 297-0372 23 E-5, F-5
Valve Gp - Control, Cab Tilt, Rotator 310-7149 24 B-1 to B-2
Valve Gp - Control, Reverse Flow Fan 234-4624 25 A-8
Valve Gp - Emergency, Boom Lower 239-8823 26 F-4
Valve Gp - Flow Control, Boom Float 255-5745 27 E-3
Valve Gp - Flow Control, Drain, Fore-Bm 4I-
7836 28 D-2
Valve Gp - Load Control, Boom Cylinder 263-1964 29 F-3, F-4
Valve Gp - Load Control, Cab Tilt Cylinder 179-2123 30 C-1
Valve Gp - Load Control, Fore-Boom Cylinder 329-7252 31 E-1
Valve Gp - Load Control, Stick Cylinder 116-3440 32 E-2
Valve Gp - Pilot, 1 Pump/ 2 Pump, Boom 119-5219 34 D-2
Valve Gp - Pilot, Bucket / Boom 232-4158 35 C-8
Valve Gp - Pilot, Fore-Boom Cylinder 206-3336 36 D-1
Valve Gp - Pilot, Stick / Sw
ing 232-4157 37 C-8
Valve Gp - Pilot, Travel 165-9522 38 D-8
Valve Gp - Press. Reducing, Bm/Swng Priority 310-0210 39 B-5
Valve Gp - Relief, Line 239-8984 40 C-4
Valve Gp - Shuttle, Pilot 185-0462 41 B-8
Valve Gp - Shuttle, Fore-Boom Pilot 8J-6875 42 D-1, E-5
Valve Gp - Solenoid, Pilot, Heavy Lift / Fore-Boom 121-6303 43 A-5, D-2
Valve Gp - Solenoid, Pilot, Negative Flow 171-0188 44 A-3
Valve Gp - Solenoid, Pilot, Stick 2 / Fr-Bm / Bm 185-0472 45 A-6, D-1
, E-3
Valve Gp - Solenoid, Pilot, Tool Rotator / Tilt Cab 185-0507 46 A-2 to A-3
Valve Gp - Solenoid, Pilot, Fan Reverse 242-6880 47 A-8
Valve Gp - Solenoid, Fore-Boom Supply 297-0370 48 D-4
Valve Gp - Solenoid and Relief, E-RV2 239-8680 49 E-5
Valve Gp - Solenoid and Relief, E-RV1 270-5649 50 E-5
Valve Gp - Solenoid, Work Tool / Free Rotate 219-7876 51 C-2
Valve Gp - Swing Motor 322-8715 52 E-8
Valve Gp - Travel Counterbalan
ce 266-7843 53 E-6, E-7
Valve GP - Main Control
259-7774
259-7777 33 C-3 to C-7
Component Locations
Motor Gp - Hydraulic Fan
Reversing Hydraulic Fan
266-8034
247-8952
6A-8
Component Locations
323-7735
PUMP & FILTER GROUP
NEGATIVE FLOW CONTROL
46
23
10
44
4 - FUNCTION WORK TOOL
CONTROL VALVE
44
LOCATED BEHIND 4-FUNCTION VALVE
NN
LL
MM
OO
36
36
51
51 18
4245
45
24
24
1
5
33
14
53
8
53
87
52
2
4
3
1011 15
38
37
35
22
6
1
13
14
42
Boom Cylinders
Fore-Boom Cylinder
Stick Cylinder
Bucket Cylinder
Hydraulic Oil
Tank
9
1
2
2
5
5
25
7
7
7
10
11
13
20
14
14 15
15
16
16
19
19 20
22
22
21
21
23
23
23
48
24
6
27
28
34
33
33
34
28
38
39
39
40
40
42
42
42
4243
43 43
43
44
44
45
45
46
46
47
47
24
48 49
49
49
50
FF
EE
KK
JJ
HH
GG
SOS
AA
BB
CC
DD
FORE-BOOM CONTROL VALVE
STICK LOAD CONTROL VALVE
TOOL ROTATOR / TILT CAB
CONTROL VALVE
BOOM FOOT
TILT CAB - FLOOR REMOVED
30
12
30 20 29
12
18
17
32
18
51
18
30
41
12
36
45
33
46
32
31
26
Tap Locations
Pressure and Sampling
Tap
Number
Description
Schematic
Location
AA Pilot Pump Delivery Pressure A-5
BB Drive Pump Delivery Pressure B-4
GG Attachment Pilot Pressure (A1) A-2
HH Attachment Pilot Pressure (A2) A-2
JJ Rotator Pilot Pressure (A3) A-2
KK Rotator Pilot Pressure (A4) A-3
SOS Hydraulic Oil Sampling Port A-5
CC Pump Power Shift Pressure A-4
DD Idler Pump Delivery Pressure A-4
EE Idler Pump Negative Flow Signal Pressure A-3
FF Drive Pump Negative Flow Signal Pressure A-3
LL Fore-Boom Pilot Pressure (P2) E-1
MM Fore-Boom Pilot Pressure (P1) E-1
NN Stick Pilot Pressure E-2
OO Auxiliary Pump Supply Pressure B-2
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
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
PILOT PUMP OUTPUT AND CIRCUIT
DRIVE PUMP OUTPUT
TOOL ROTATOR CIRCUIT
LEFT TRAVEL MOTOR CIRCUIT
AUXILIARY PUMP OUTPUT
POWER SHIFT CONTROL CIRCUIT
COOLING FAN CIRCUIT
SUPPLY LINE
STICK CYLINDER CIRCUIT
FORE-BOOM CYLINDER CIRCUIT
ATTACHMENT CIRCUIT
SWING MOTORS CIRCUIT
DRAIN / RETURN LINE
SWING BRAKE CONTROL CIRCUIT
IDLER PUMP OUTPUT
TRAVERL SPEED CONTROL CIRCUIT
BUCKET CYLINDER CONTROL CIRCUIT
RIGHT TRAVEL MOTOR CIRCUIT
BOOM CYLINDERS CONTROL CIRCUIT
TILT CAB CONTROL CIRCUIT
KENR9543
30 Page, (Dimensions: 39 inches x 28 inches)
THIS SCHEMATIC IS FOR THE 345C UHD EXCAVATOR
MEDIA NUMBER: KENR9543
PART NUMBER: 323-6661, CHANGE: 03, VERSION: V
Components are shown installed on a fully operable machine.
Refer to the appropriate Service Manual for Troubleshooting, Specifications.
12345678
A
B
C
D
E
F
12345678
A
B
C
D
E
F
NOTE A: FREE ROTATE PRESSURE SWITCH
(89.6-107 BARS)
NOTE B: FREE ROTATE VALVE ACTUATED BY PRESSURE SWITCH
(UHD FRONT PARTS)
SEE SCHEMATIC ELEC. 261-5157 FOR FURTHER DETAILS
ABOUT BOOM RECOGNITION
NOTE C: STICK IN SELECTION VALVE 1/2 PUMP (ON IN UHD)
NOTE D: FORE-BOOM DEACTIVATED PTA PRESSURE SWITCH ON
NOTE E: HYDRAULIC SCHEMATIC SHOWS MACHINE IN UHD CONFIGURATION.
VALVES SHOWN IN NEUTRAL POSITION.
FOR INFORMATION ABOUT MACHINE IN RETROFIT POSITION,SEE
STD HYDRAULIC SCHEMATIC (SLCV) 230-2713.
AL3 BL3
A
Pp
TD
C1
STICK CYLINDER
p2p1LS
TP
FORE-BOOM CYLINDER
B
A
AR3BR3bR3
dR4
BUCKET CYLINDER
Dr
32
1
p
t
NOTE D
T
A
P
A
B
A
B
T
C1’
TILT CAB CYLINDER
C2'
V2
V1
C2C1
CDAB
Pb PaP
LS
M
BOOM
CYLINDER
BOOM
CYLINDER
SW-1
DR
DR
B
A
B
A
CYL
Dr
CV
Pi
X
X
CYL
Dr
CV
Pi
T
T
A
B
P
T
A
bL4
bL4-1
BL4
AL4
NOTE B
TOOL ROTATOR
T-OUT2
TRAVEL MOTOR (LEFT)
TRAVEL MOTOR (RIGHT)
X
BA
B
A
AG
AG
BG
BG
T2
T2
T1
T1
BR
BR
X
DOUBLE
SINGLE
DOUBLE
SINGLE
P
T
A1
A2
B1
B2
DR
DR
DR
B
A
A
B
A
B
DR
B
A
L
B
A
A
B
L
AR1BR1 AL1 BL1
T
P
A1B1A2B2A3B3A4B4
aL2
NOTE A
bL2
SWING MOTOR
SWING MOTOR
BOOM
STICK(2)
BUCKET
ATCH
TRAVEL(R)
TRAVEL(L)
SWING
STICK
BOOM(2)
TRAVEL(R)TRAVEL(L)
SWINGSTICK BOOMBUCKET
OUT IN R L OPEN CLOSE DOWN UP
HL
aL5
Dr
R2
X
Pp1
R1
Y
HR
AR4
R3
Pi1P2 P-IN PSA2 DR1
T-OUT2
DR2
DR3 DR4 Pi2 DR5 DR6T-OUT1
P1 P2
T
B1
A1
B2
A2
A4
B1
Dr1
Di
PS2
PB
Pi2
D0
PS1
Pi1
a2
a5
a3
A2
a1
a4
A1
PSV
P1
PG2
PB2
DE2
B2
A2
PA2
M2
DB2
PG1
PB1
DE1
B1
A1
PA1
M1
DB1
BA
dL5
(DOWN)
(UP)
(CLOSE)
AL2
BL2
PAT
(OPEN)
bL2
(F)(B)
PTAPSW
(BACK)
(FWD)
dST1
(BACK)
(F)
(B)
(R)
(FWD)
(L)
(R) (L)
dSW
PiL
(IN)
(OUT)
(UP)
APi2
dR5
PSA1
(IN)
Pp2
PC
PG
T
OUT
IN
TP
TT
BACK FWD FWD
T2T1
T3
T4
BACK
JLP
JLT
JL1 JL3 JL2 JL4 JR4 JR2 JR3 JR1
JRP
JRT
PiH
A1
B1
A2
B2
A3
B3
A4
B4
A5
B5
A6
B6
A7
B7
A8
B8
A
B
P
T
A
CA
CD
CB1
CB2
8
1
7
6
2
4
P
T
A
S
L1
L
B
X
AR2 BR2
bR1 aR1
aL1
bL1
aR3 bR2 bR3 aR2aR4 bL3 bL4-1 aL3
AR3
BR3
aR3
BR2 AR2
bR2
BR1
AR1
bR1
bL1
BL1
AL1
bL3
BL3
AL3
BL4
AL4
bR3 aR2 aR1
PR
PL
aL1 aL3 bL4
PR
PL
aL2
bL2
aR4
aL4
aL4
NO.1
(TRAVEL)
NO.2
(SWING)
NO.3
(LOCK)
dR4
μμμ μ
DR
DR1
L2
L3
A
B
P
T
A
(OUT)
NOTE D
NOTE C
T-OUT2
BA
TP
S
S
T
Pi
LL
MM
NN
OO
GGHH
JJ
KK
FF
EE
DD
CC
BB
AA
SOS
MOTOR GP
SWING
334-9975
VALVE GP
SWING MOTOR
322-8715
MOTOR GP
TRAVEL
232-6180
VALVE GP
TRAVEL
COUNTERBALANCE
266-7843
VALVE GP
TRAVEL
COUNTERBALANCE
266-7843
SWIVEL GP
225-4547
VALVE GP
CHECK
(E-CV3)
297-0372
VALVE GP
SOLENOID / RELIEF
(E-RV2)
239-8680
VALVE GP
CHECK
(E-CV2)
297-0372
VALVE GP
CHECK
(E-CV1)
297-0372
VALVE GP
SOLENOID / RELIEF
(E-RV1)
270-5649
VALVE GP
SOLENOID
297-0370
VALVE GP
SHUTTLE
8J-6875
SWITCH AS
PRESSURE
FREE ROTATE
266-5881
VALVE GP
LOAD CONTROL
BOOM CYLINDER
263-1964
VALVE GP
LOAD CONTROL
BOOM CYLINDER
263-1964
VALVE GP
CHECK
BOOM FLOAT, UP
(E-CV1)
215-4890
VALVE GP
EMERGENCY
BOOM LOWER
239-8823
VALVE GP
CHECK
BOOM FLOAT, UP
(E-CV2)
215-4890
VALVE GP
FLOW CONTROL
BOOM FLOAT
255-5745
VALVE GP
SOLENOID
185-0472
VALVE GP
CHECK
202-6281
VALVE GP
LOAD CONTROL
STICK CYLINDER
116-3440
VALVE GP
CHECK
233-7881
VALVE GP
LOAD CONTROL
FORE-BOOM CYLINDER
329-7252
VALVE GP
CHECK
233-7881
VALVE GP
CHECK
233-7881
VALVE GP
SHUTTLE
8J-6875
VALVE GP
SHUTTLE
8J-6875
VALVE GP
SOLENOID
185-0472
VALVE GP
PILOT,
FORE-BOOM
CYLINDER
206-3336
VALVE GP
FLOW CONTROL
DRAIN
FORE-BOOM
4I-7836
VALVE GP
PILOT
1PUMP / 2PUMP
BOOM
119-5219
VALVE GP
SOLENOID
121-6303
VALVE GP
SOLENOID
WORK TOOL
FREE ROTATE
219-7876
VALVE GP
LOAD CONTROL
CAB TILT CYLINDER
179-2123
VALVE GP
CONTROL
CAB TILT / ROTATOR
310-7149
VALVE GP
SOLENOID
185-0507
VALVE GP
SOLENOID
171-0188
PUMP GP
HYDRAULIC FAN
259-0814
PUMP GP
DRIVE, IDLER, PILOT
322-8732
PUMP GP
AUXILIARY
136-8899
VALVE GP
RELIEF, LINE
239-8984
VALVE GP
MAIN CONTROL
323-7735
TEE AS
164-5550
SWITCH AS
309-5769
VALVE GP
CHECK
239-9036
FILTER AND VALVE GP
HYDR. OIL
158-8987
VALVE GP
SOLENOID
121-6303
VALVE GP
PRESS. RED.
BM /SWING PRIORITY
310-0210
ACCMLTR GP
HYDR.
164-6981
VALVE GP
SOLENOID
185-0472
FILTER GP
CASE DRAIN RETURN
126-2075
FILTER GP
HYDR. OIL RETURN
173-3434
FILTER GP
CASE DRAIN RETURN
126-2075
MANIFOLD GP
CONTROL
PILOT OIL SUPPLY
215-5037
VALVE GP
CONTROL
REV. FAN FLOW
234-4624
MOTOR GP
HYDR. FAN : 266-8034
REVERSING HYDR. FAN : 247-8952
VALVE GP
SOLENOID
242-6880
VALVE GP
CHECK
COOLER BYPASS
123-2505
VALVE GP
CHECK
COOLER
185-0384
VALVE GP
SHUTTLE
185-0462
VALVE GP
PILOT
STICK / SWING
232-4157
VALVE GP
PILOT
BUCKET / BOOM
232-4158
VALVE GP
PILOT, TRAVEL
165-9522
SWITCH AS
PRESSURE
FORE-BOOM
PILOT
309-5769
MOTOR GP
SWING
334-9975
