INTERACTIVE SCHEMATIC
The Bookmarks panel will allow you to
quickly navigate to points of interest.
Click on any text that is BLUE and underlined.
These are hyperlinks that can be used to navi-
gate the schematic and machine views.
When only one callout is showing on a machine view this
button will make all of the callouts visible. This button is
located in the top right corner of every machine view page.
VIEW ALL CALLOUTS
Cover Page
Information
Schematic
Machine Views
Component Table
Tap Table
Fluid Power Symbols
Electrical Symbols
Front Frame
Rear Frame
Tap Views
Features
Options
Bookmarks
X
EC-C3
EC-C2
E-C60
EC-C1
E-C61
To set your screen resolution do the following:
RIGHT CLICK on the DESKTOP.
Select PROPERTIES.
CLICK the SETTINGS TAB.
MOVE THE SLIDER under SCREEN RESOLUTION
until it shows 1024 X 768.
CLICK OK to apply the resolution.
This document is best viewed at a
screen resolution of 1024 X 768.
FUNCTION
Zoom In
HOTKEYS (Keyboard Shortcuts)
Zoom Out
Fit to Page
Hand Tool
“CTRL” / “+”
KEYS
“CTRL” / “-”
“CTRL” / “0” (zero)
“SPACEBAR” (hold down)
Find
“CTRL” / “F”
©
2006 Caterpillar, All Rights Reserved
Printed in U.S.A.
RENR7126-01
July 2006
System 5: Two-Way / One Pump / Pedal
345C Excavator
Hydraulic System - Attachment
TBA1-UP
ESD1-UP
WDE1-UP
TDG1-UP
TAJ1-UP
DHP1-UP
GJR1-UP
PJW1-UP
BWY1-UP
COMPONENT LOCATION
Description
Part
Number
Machine
Location
Schematic
Location
Control Gp - Hydraulic Pedal 206-3336 1 E-8
Valve Gp - Relief (Attachment) 239-8964 2 C-3
Accumulator Gp - Pilot Manifold 164-6981 19 B-5
Block Note B 20 D-8
Cylinder Gp - Boom Note A 21 E-1
Cylinder Gp - Bucket Note A 22 E-2
Cylinder Gp - Stick Note A 23 E-6
Filter Gp - Case Drain 126-2075 24 A-5
Filter Gp - Pilot 158-8987 25 A-4
Filter Gp - Return Oil 173-3434 26 A-6
Motor Gp - Cooling Fan 242-6904 27 A-7
Motor Gp - Left Swing 225-4506 28 F-7
Motor Gp - Left Travel 232-6180 29 F-5
Motor Gp - Right Swing 225-4506 30 F-6
Motor Gp - Right Travel 232-6180 31 F-4
Pump Gp - Cooling Fan 259-0814 32 B-2
Pump GP - Drive / Idler / Pilot Hydraulic 259-0818 33 B-3
Swivel Gp 225-4517 34 E-4
Tank Gp - Hydraulic Oil 227-0431 35 A-6
Valve Gp - Boom/Swing Priority 232-4102 36 B-4
Valve Gp - Cooler Bypass Check 123-2505 37 B-7
Valve Gp - Heavy Lift Solenoid 121-6303 38 B-4
Valve Gp - Left Fine Swing Motor 116-3420 39 E-7
Valve Gp - Left Travel/Brake 165-9338 40 E-5
Valve Gp - LH Pilot Control (Stick/Swing) 232-4157 41 C-8
Valve Gp - Main Control 230-2760 42 D-4
Valve Gp - Pilot Manifold 215-5037 43 B-5
Valve Gp - Pilot Control Travel 165-9522 44 D-8
Valve Gp - Power Shift Control Solenoid 225-4518 45 B-2
Valve Gp - RH Pilot Control (Bucket/Boom) 232-4158 46 C-7
Valve Gp - Right Travel/Brake 165-9338 47 E-4
Valve Gp - Slow Return Check 185-0384 48 B-7
Note A: Refer to parts manual for specific cylinder information.
System 5 Attachment
Standard 345C
Note B: Part numbers are located on the main Hydraulic System Schematic according
to the effectivity of the machine.
TAP LOCATION
Tap
Number
Description
Schematic
Location
AA Pilot Pump Delivery Pressure A-4
BB Drive Pump Delivery Pressure B-2
CC Pump Power Shift Pressure A-2
DD Idler Pump Delivery Pressure A-2
SOS Hydraulic Oil Sampling Port
A-4
FLUID POWER SYMBOLS
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 PEDALGENERAL 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
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 ACTINGSINGLE 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
ATTACHMENT
MANUAL SHUTOFF
SHUTTLE PILOT
CONTROLLED
ELECTRICAL SYMBOLS
Hydraulic Symbols (Electrical)
325-AG135 PK-14
Circuit Identification
Number
Wire Color
Wire Gauge
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
A
Wire
Wire
(EXAMPLE VALVE)
Current Standard
Transducer
(Fluid)
Transducer
(Gas / Air)
G
Generator
Electrical Wire
Pressure Switch
M
Electric Motor
Pressure Switch
(Adjustable)
Temperature Switch
Pressure
Symbol
Temperature
Symbol
Level
Symbol
Flow
Symbol
Electrical Symbols (Electrical)
T
LINE PATTERNS
Drain / Return Lines
Component Group
Pilot / Load Sensing Pressure
Pressure Line
Attachment
Air Line
CALLOUTS
Taps (Pressure, Sampling,Sensor) by letter
YY
THIS SCHEMATIC IS FOR THE 345C (ATTACHMENT)
PART #: 230-2701 HE02
This Attachment Schematic is intended to be used with the Standard Hydraulic Schematic
for the specific machine.
Refer to the appropriate Service Manual for Troubleshooting, Specifications and Systems Operations
DRAIN / RETURN LINE
HYDRAULIC CIRCUIT COLOR DESCRIPTIONS
DRIVE PUMP OUTPUT
IDLER PUMP
POWER SHIFT CONTROL CIRCUIT
PILOT PUMP OUTPUT
COOLING FAN PUMP
ATTACHMENT CONTROL CIRCUIT
SUPPLY LINE
BUCKET CONTROL & BUCKET CYLINDER CIRCUIT
RIGHT TRAVEL CONTROL & RIGHT TRAVEL MOTOR CIRCUIT
TRAVEL SPEED CONTROL CIRCUIT
STICK CONTROL & STICK CYLINDER CIRCUIT
BOOM CONTROL & BOOM CYLINDER CIRCUIT
NEGATIVE FLOW CONTROL CIRCUIT
LEFT TRAVEL CONTROL & LEFT TRAVEL MOTOR CIRCUIT
SWING CONTROL & SWING MOTOR CIRCUIT
SWING BRAKE CONTROL CIRCUIT
1
2
3
4
56
7
8
A
C
D
E
F
1
23
4
56
7
8
A
B
C
D
E
F
B
(43) VALVE GP
PILOT
MANIFOLD
215-5037
(19) ACCUMULATOR GP
PILOT
MANIFOLD
164-6981
FILTER GP
DRAIN RETURN
(35) TANK GP
HYDRAULIC OIL
227-0431
(26) FILTER GP
RETURN OIL
173-3434
BB
CC
DD
SOS
AA
(22) CYLINDER GP
BUCKET
(21) CYLINDER GP
BOOM
(23) CYLINDER GP
STICK
BOOM(1) STICK(2)BUCKETATCHTRAVEL(R)TRAVEL(L)SWINGSTICK(1)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
T-OUT2 DR2
DR4 Pi2 DR5 T-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
X
B
A B
A
AG
BG
BG
AG
L
L
T2
T2
T1
T1
BR
BR
dL5(DOWN)
BPi
BDr
(UP)(CLOSE)
AL2BL2PAT
(OPEN)
(B) (F)PTAPSW
(BACK)
(FWD)dST1
(BACK)
(F)(B)
(R)
(FWD)(L)
(R) (L)
dSWPiL(IN)
(OUT)
APi
ADr
(UP)
APi2 dR5
PSA1
X
(IN)
Pp2
PC
PG
T
OUT IN
TP
TT
BACK
FWD FWD
T2
T1
T3
T4
BACK
JLP
JLT
JL1 JL3 JL2 JL4 JR4 JR2 JR3 JR1
JRP
JRT
PiH
A1
A2
A3 A4
A5
A6
A7
A8
B1
B2
B3
B4
B5
B6
B7
B8
8
1
7
6
B
B
A
A
P
T
1 23
DR6
DR1
DR3
P
T
A
S
L
L1
X
B
(OUT)
bR4
aL4
BR3 AR3
AR2 BR2
AL3BL3
BL4 AL4
AR1BR1 AL1 BL1
bR1
aR1 aL1 bL1
aR4 bL3 bL4 aL3 aR3 bR2 bR3 aR2
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
NO.1
(TRAVEL)
NO.2
(SWING)
NO.3
(LOCK)
bL2
aR4
bL2
µµµ µ
µµµ µµµµ µ
DR
DR1
L2
L3
A
B
aL2
aL2
HIGH PRESS. LINE
5
(33) PUMP GP
DRIVE/IDLER
AND PILOT
HYDRAULIC
259-0818
(45) VALVE GP
POWER SHIFT
CONTROL SOL
225-4518
(32) PUMP GP
COOLING FAN
259-0814
(24) FILTER GP
CASE DRAIN
126-2075
(36) VALVE GP
BOOM/SWING
PRIORITY
232-4102
(25) FILTER GP
PILOT
158-8987
(38) VALVE GP
HEAVY LIFT
SOLENOID
121-6303
(27) MOTOR GP
COOLING FAN
242-6904
(37) VALVE GP
CHECK
COOLER
BYPASS
123-2505
(48) VALVE GP
CHECK
SLOW RETURN
185-0384
(44) VALVE GP
PILOT CONTROL TRAVEL
165-9522
(20) BLOCK
(41) VALVE GP
LH PILOT CONTROL
STICK/SWING
232-4157
(46) VALVE GP
RH PILOT CONTROL
BUCKET/BOOM
232-4158
(1) CONTROL GP
HYDRAULIC
PEDAL
206-3336
(28) MOTOR GP
LEFT SWING
225-4506
(39) VALVE GP
LEFT FINE
SWING MOTOR
116-3420
(30) MOTOR GP
RIGHT SWING
225-4506
FINE
SWING
(31) MOTOR GP
RIGHT TRAVEL
232-6180
(40) VALVE GP
LEFT TRAVEL/BRAKE
165-9338
(47) VALVE GP
RIGHT TRAVEL/BRAKE
165-9338
(34) SWIVEL GP
225-4547
(29) MOTOR GP
LEFT TRAVEL
232-6180
(42) VALVE GP
MAIN CONTROL
230-2760
(2) VALVE GP
ATTCH RELIEF
239-8964
MACHINE COMPONENT LOCATIONS
48
48
47
47
46
46
44
44
43
43
42
42
41
41
40
40
39
39
38
38
37
37
36
36
34
34
35
35
32
32
31
31
30
30
29
29
28
28
27
27
26
26
25
25
24
24
23
23
22
22
21
21
21
20
20
19
19
2
2
1
1
VIEW ALL CALLOUTS
PUMP AND FILTER GROUP
45
33
SOS
DD
CC
BB
AA
VIEW ALL CALLOUTS
