RENR2520-01 September 2012
FLUID POWER SYMBOLS BASIC COMPONENT SYMBOLS MAIN
Component Location
Tap Location Pressure and Sampling Tap Number G1
Lift Cylinder Head End Pressure
G2
Connector - Orifice
Lift Cylinder Rod End Pressure
Cooler - Hydraulic Oil Cylinder Gp - Lift
B-2 B-2
G3
Tilt Cylinder Head End Pressure
D-2
G4
Tilt Cylinder Rod End Pressure
D-2
G5
Oil Sampling Port
G-5
G6
Implement Pilot Pressure
F-8
Cylinder Gp - Tilt (LH) Cylinder Gp - Tilt (RH)
43 42
38
44 37
FLUID CONDITIONER
SPRING
CONTROL VALVES
VARIABILITY
SPRING (ADJUSTABLE)
LINE RESTRICTION (VARIABLE)
PRESSURE COMPENSATION
RESTRICTION
LINE RESTRICTION (FIXED)
AUX
PUMP (2 - SECTION)
Part Machine Schematic Number Location Location
Description
Schematic Location
Description
PUMP OR MOTOR
4I-6206
1
E-6, E-5
355-1656
2
B-8
3
C-1
4
C-1
5
D-1
(STD)
193-4076
(High Lift)
193-4075
(STD)
112-3172
(High Lift)
219-6272
(STD)
112-3171
(High Lift)
219-6273
Filter Gp - Case Drain (Center Imp. Pump)
8E-0769
6
C-7
Filter Gp - Case Drain (Left Imp. Pump)
8E-0769
7
B-7
Filter Gp - Case Drain (Right Imp. Pump)
8E-0769
8
D-7
Filter Gp - Oil (Pilot)
8E-0769
9
C-7 B-8
Filter Gp - Oil (Cooler Screen)
6E-0874
10
Gauge - Liquid Level
147-9560
11
A-5
Pump Gp - Gear (Pilot, Hyd. Oil Cooler)
6E-0456
12
C-7 C-6
Pump Gp - Implement (Center)
112-5381
13
Pump Gp - Implement (Left)
124-3761
14
A-6
Pump Gp - Implement (Right)
124-3761
15
C-6
Screen As
9T-9227
16
A-7
Screen Gp
7J-2656
17
A-7
Screen Gp - Hydraulic
169-4073
18
B-5, C-6, D-6
Sender - Temperature (Hyd. Oil)
8N-3844
19
A-8
Sensor Gp - Pressure (Lift)
3E-6934
20
B-2
Sensor Gp - Temperature (Hyd. Oil)
100-3055
21
A-8
Switch As - Pressure (Imp. Oil Cooling Filter)
144-5661
22
B-8
Switch Gp - Bypass (Pilot Oil Filter)
164-7577
23
C-8
Switch Gp - Liquid Level
123-2993
24
A-5
Tank As - Expansion
225-3743
25
A-4
Tank As - Expansion (LH)
221-3694
26
A-5
Tank As - Expansion (RH)
221-3693
27
A-4
Tank Gp - Hydraulic (Implement)
131-6448
28
A-7
Valve - Breaker Relief (Filler)
9T-0818
29
A-2
Valve - Breaker Relief (Expansion Tank)
220-0812
30
A-3
Valve Gp - Check (Cooler)
6E-1454
31
B-8
Valve Gp - Check (Implement)
117-3513
32
D-6, B-6
Valve Gp - Check (Implement)
140-0491
33
C-6
Valve Gp - Check (Pilot)
6E-5444
34
D-8
Valve Gp - Check (Pilot Ctrl)
9T-3096
35
D-7
Valve Gp - Cooler Bypass
6E-4473
36
C-8
Valve Gp - Main Control (LH)
133-8675
37
C-3
Valve Gp - Main Control (RH)
133-8673
38
C-4
Valve Gp - Pilot (Tilt, Lift)
119-5991
39
F-7
Valve Gp - Relief (Main)
6E-6197
40
D-6, C-6, B-6
Valve Gp - Relief (Pilot)
118-0018
41
D-8
Valve Gp - Relief (Tilt Cyl. Head End)
9T-9196
42
C-3
Valve Gp - Relief (Tilt Cyl. Rod End)
9T-9197
43
C-3
Valve Gp - Relief (Lift Cyl. Head End)
142-4281
44
B-3
Valve Gp - Selector (Hydraulic)
140-8243
45
E-6, E-5
Valve Gp - Selector and Pressure Ctrl
119-5988
46
E-8
ATTACHMENT
VALVE PORTS
THREE POSITION
TWO - WAY
THREE - WAY
CONTROL VALVES
FOUR - WAY
CHECK VALVES
A B
P T
P T
NORMAL POSITION
SHIFTED POSITION
BASIC SYMBOL
INFINITE POSITION
SPRING LOADED
SHUTTLE
PILOT CONTROLLED
FLUID STORAGE RESERVOIRS
PRESSURIZED
VENTED
994D Wheel Loader Hydraulic System
RETURN ABOVE FLUID LEVEL
RETURN BELOW FLUID LEVEL
MEASUREMENT
PRESSURE
ROTATING SHAFTS
TEMPERATURE
FLOW
UNIDIRECTIONAL
BIDIRECTIONAL
COMBINATION CONTROLS
3TZ1-UP SOLENOID
SOLENOID OR MANUAL
SOLENOID & PILOT
SOLENOID & PILOT OR MANUAL
SERVO
THERMAL
DETENT
MANUAL CONTROL SYMBOLS
PUSH - PULL LEVER
GENERAL MANUAL
MANUAL SHUTOFF
EXTERNAL RETURN
INTERNAL RETURN
GAS CHARGED
© 2012 Caterpillar, All Rights Reserved
FIXED DISPLACEMENT
SINGLE ACTING
BIDIRECTIONAL
BIDIRECTIONAL
DOUBLE ACTING
INTERNAL PASSAGEWAYS
VARIABLE DISPLACEMENT NON-COMPENSATED
UNIDIRECTIONAL
INTERNAL SUPPLY PRESSURE
HYDRAULIC & PNEUMATIC CYLINDERS
LINES JOINING
UNIDIRECTIONAL
Volume 1 of 2: Implement System
COMPLETE
HYDRAULIC MOTORS
VARIABLE DISPLACEMENT NON-COMPENSATED
SPRING
REMOTE SUPPLY PRESSURE
SIMPLIFIED
LINES CROSSING
HYDRAULIC PUMPS FIXED DISPLACEMENT
PEDAL
CROSSING & JOINING LINES
ACCUMULATORS
SPRING LOADED
PUSH BUTTON
PILOT CONTROL SYMBOLS
RELEASED PRESSURE
Check Part Numbers in the Parts Manuals for your Specific Machine
MAIN CONTROL VALVE
TWO POSITION
AB
LINE RESTRICTION (VARIABLE & PRESSURE COMPENSATED)
VALVES
VALVE ENVELOPES
ONE POSITION
HYDRAULIC PNEUMATIC ENERGY TRIANGLES
PUMP (VARIABLE & PRESSURE COMPENSATED)
INFINITE POSITIONING
3 POSITION
FLOW IN ONE DIRECTION
PARALLEL FLOW
CROSS FLOW
2 POSITION
FLOW IN EITHER DIRECTION
Printed in U.S.A.
ELECTRICAL SYMBOLS TABLE
10 22 G6
41
31 36 39 12
29
31
40 30
22 4
16
G3 G6 G2 29
41 39 G1 30 40 5
36
G
27 32
M
TRANSDUCER (FLUID)
TRANSDUCER (GAS / AIR)
GENERATOR
ELECTRIC MOTOR
PRESSURE SWITCH
PRESSURE SWITCH (ADJUSTABLE)
TEMPERATURE SWITCH
ELECTRICAL WIRE
33
28
11 ELECTRICAL SYMBOLS (ELECTRICAL)
4 20
T
PRESSURE SWITCH
TEMPERATURE SWITCH
17 45 46 1
34 35
G1 G3 G2 G4
5
3
2
34 46 45 G5 35 1
3 12
8
ELECTRICAL SCHEMATIC EXAMPLE
HYDRAULIC SCHEMATIC EXAMPLE
CURRENT STANDARD
CURRENT STANDARD
HARNESS IDENTIFICATION CODE THIS EXAMPLE INDICATES WIRE 135 IN HARNESS “AG”
19
WIRE CIRCUIT NUMBER IDENTIFICATION
325-AG135 PK-14
21
CIRCUIT NUMBER IDENTIFICATION
WIRE COLOR
WIRE COLOR
WIRE GAUGE
325-PK
PREVIOUS STANDARD
6 23
9
7
18
WIRE
FRONT FRAME - LEFT REAR VIEW
WIRE COLOR
B
325-PK-14
CIRCUIT NUMBER IDENTIFICATION
MACHINE COMPONENT LOCATIONS
FLOW SWITCH
WIRE NUMBER IDENTIFICATION CODES
24 2
LEVEL SWITCH
WIRE GAUGE
A
(EXAMPLE VALVE)
(Dimensions: 39 inches x 28 inches)
10
14 13 15 25 26
30 Page,
G4
RENR2520-01 VOL 1 of 2
HYDRAULIC SYMBOLS (ELECTRICAL)