RENR3756-04
September 2011
345B Series II Excavator
Hydraulic System
Printed in U.S.A.© 2011 Caterpillar, All Rights Reserved
345BII:
ALB1-UP
ALD1-UP
AMD1-UP
AKJ1-UP
AMJ1-UP
AMN1-UP
AYR1-UP
AGS1-UP
AKX1-UP
DCW1-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
RENR3756-04
16 Page, (Dimensions: 34 inches x 24 inches)
PG
PSA
T-O UT
DR6
DR5
DR4
Pi8
Pi3
Pi2
Pi1
PAC
DR3
DR2
DR1
Pi5
JPi
C/V
PEPU
P-IN
f03780
43
49
48
47
46
50
Pilot Oil Manifold
51
AL4
BL3 BL2
BL1
BL4
AL3
AL2
AL1
X
PTA
PSW
PiH
BR1
BR2
AR3
AR4
AR1
AR2
BR3
Y
36
18
17
30
29 28
27
26
24
25
23
0222
13
31
37
38
12
14
Main Control Valve
21
SE
RI
E
S
I
I
3
54
6
56
32
47
45
41
59
63
10
9
60 61
14
1
2
19
5
8
Travel Motor (Right)
Item
Component
STANDARD COMPONENTS
Component
No.
Item
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
27
26
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
Left Swing Motor
Right Swing Motor
Travel Motor (Left)
Stick Cylinder
Travel Brake Valve (Left)
Travel Brake Valve (Right)
Bucket Cylinder
Boom Cylinder
Swivel
Boom Raise Pressure Switch
Stick Drift Reduction Valve
Line Relief Valve (Stick Cyliner Rod End)
Main Control Valve
Implement/Swing Pressure Switch
Travel Pressure Switch
Line Relief Valve (Boom Cylinder Head End)
Boom Drift Reduction Valve
Pilot Control Valve (Trav
el)
Boom II Control Valve
Stick I Control Valve
Swing Control Valve
Left Travel Control Valve
Straight Travel Control Valve
Main Relief Valve
Right Travel Control Valve
Attachment Control Valve
Bucket Control Valve
Boom I Control Valve
Stick II Control Valve
Line Relief Valve (Stick Cylinder Head End)
Valve (Regeneration)
Valve (Regeneration and Cut)
Pressure Control Valve
Logic Valve
Line Relief Valve (Bucket Cylinder Head End)
Line Relief Valve (Bucket Cylinder Rod End)
Line Relief Valve (Boom Cylinder Rod End)
Negative Flow Control Relief Valve
Pilot Filter
Hydraulic Activation Control Valve
Accumulator
Drain Filter
Solenoid Valve (Fine Control)
Solenoid Valve (Travel Speed)
Solenoid Valve (Swing)
Pilot Relief Valve
Pilot Oil Manifold
Upper Pump
Lower Pump
Automatic Travel Speed Change Valve
Cooling Pump
Pilot Pump
Sl
ow Return Check Valve
Bypass Check Valve
Return Filter
Oil Cooler
Radiator
Fan Motor
Hydraulic Tank
Cooling Pump Relief Valve
Screen
Pilot Control Valve (Stick/Swing)
Pilot Control Valve (Boom/Bucket)
Proportional Reducing Valve (Powershift)
55
53
RENR3756-04
16 Page, (Dimensions: 34 inches x 24 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.
SCHEMATIC PART NUMBER: 165-9624
MEDIA NUMBER: RENR3756-03
THIS SCHEMATIC IS FOR THE 345B SERIES II EXCAVATOR HYDRAULIC SYSTEM
A
B
C
D
E
1234567
A
B
C
D
E
1234567
44
Hydraulic Schematic
MAIN CONNNECTOR LINE
PILOT LINE
DRAIN LINE
165-9624
BA
DR1
MU
SWING
MOTOR
`
PG1
SWING
MOTOR
MU
DR2
AB
3GP2GP
(COOLANT)
B
STICK
SWING
BOOMBUCKET
JR1
JR3
JR4
JR2
JRT
JRP
JL2
JL4
JL1
JL3
JLT
JLP
AR1
BR1
AL2BL2
X
DR
HL
dL5
aL5
BL4
bL4
AL3
BL3aL3
bL2
AL1
BL1
aL1
PSW
aR1
aR2
AR2
BR2
bR3
aR4
Y
HR
AR4
R1
dSW
LP1Rb2RbPR
Pp1
bL1
PAT
aL2 bL3 aL4
BOOM(1)
BUCKETATCH
TRAVEL(R)
PiL
aR3dR4
SA5
SA4
SA3
SA2
SA1
SB5 SB4
SB3
SB2
SB1
SP
(B)
BPi
(F)
(B)
(R)
(L)
SWING
(F)
L
L1
S
ST
(DOWN)
(OPEN)
(FWD)
(FWD)
(L)
(IN)
(UP)
(CLOSE)
(UP)
(IN,OUT,DOWN)
dR5
(BACK)
(BACK)
(R)
AR3
R1
S
R2
X1
X2
M3
X3
A1
M1
A2
M2
R1
A3
T1
RIGHT
L'L'
(OUT)
BR3
R2
'A'B
S2
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
(SLOW)
Pi3
(TRAVEL)
(SWING)
PIN
PEU
(PUMP)
Pi1
Pi2C/V
TRACK
JPi
Pi5
(RELIEF)
T2
PTA
X
T2
MA
(OIL)
TT
TP
TRAVEL(R)
PAC
TRAVEL(L)
TLA1
BDr
2ART2ALT
TRA1
B
X
PSL
A
X
APi
ADr
AL4
5
1
2
3
6
4
7
10
19
12
13
20
31
32
33
21
34
35
22
23
24
25
14
15
16
40
42
57
58
60
61
64
62
59
45
63
46
47
48
49
50
51
43
65
41
52
53
54
56
55
8
99
26
27
28
29
36
37
38
30
17
18
39
11
39