FLUID POWER SYMBOLS
SENR5884-01 November 2003
BASIC COMPONENT SYMBOLS MAIN AUX.
PUMP or MOTOR
LINE RESTRICTION (FIXED)
RESTRICTION
PRESSURE COMPENSATION
LINE RESTRICTION (VARIABLE)
SPRING (ADJUSTABLE)
VARIABLILTY
CONTROL VALVES
SPRING
FLUID CONDITIONER
PUMP: VARIABLE and PRESSURE COMPENSATED
2-SECTION PUMP
HYDRAULIC PNEUMATIC ENERGY TRIANGLES
ATTACHMENT
LINE RESTRICTION VARIABLE and PRESSURE COMPENSATED
VALVES VALVE ENVELOPES
TWO POSITION
ONE POSITION
2
1 2
1
3
3
4 5
5
4
6
5 7
6
8
9
7
8
11
10
VALVE PORTS
TWO-WAY
THREE POSITION
FOUR-WAY
THREE-WAY
9
CONTROL VALVES
12
P T SHIFTED POSITION
P T NORMAL POSITION
A
CHECK VALVES
AB
AB
INFINITE POSITION
SPRING LOADED
BASIC SYMBOL
A AA
MEASUREMENT
ROTATING SHAFTS
BB PRESSURE
FLOW
TEMPERATURE
980G Wheel Loader Hydraulic System
CC 17
15 16
B
BIDIRECTIONAL
FLUID STORAGE RESERVOIRS
13
14
UNIDIRECTIONAL
18
19
B
DD EE
20
VENTED
RETURN ABOVE FLUID LEVEL
PRESSURIZED
RETURN BELOW FLUID LEVEL
COMBINATION CONTROLS
9CM1-Up 2KR1-Up 2SR1-Up
SOLENOID or MANUAL
SOLENOID
SERVO
SOLENOID and PILOT or MANUAL
SOLENOID and PILOT
DETENT
THERMAL
MANUAL CONTROL SYMBOLS
22
21
PUSH-PULL LEVER
PEDAL
PUSH BUTTON
GENERAL MANUAL
SPRING
PILOT CONTROL SYMBOLS
FF 24
23
GG
25
RELEASED PRESSURE
26
EXTERNAL RETURN
HH 27
28
29
30
31
INTERNAL RETURN
SIMPLIFIED
CROSSING AND JOINING LINES
ACCUMULATORS
C
C
REMOTE SUPPLY PRESSURE
SPRING LOADED
GAS CHARGED
LINES CROSSING
HYDRAULIC PUMPS FIXED DISPLACEMENT
32
HYDRAULIC AND PNEUMATIC CYLINDERS
SINGLE ACTING
LINES JOINING
VARIABLE DISPLACEMENT NON-COMPENSATED
FIXED DISPLACEMENT
UNIDIRECTIONAL
UNIDIRECTIONAL
BIDIRECTIONAL
BIDIRECTIONAL
DOUBLE ACTING
INTERNAL PASSAGEWAYS
HYDRAULIC MOTORS
VARIABLE DISPLACEMENT NON-COMPENSATED
INTERNAL SUPPLY PRESSURE
COMPLETE
TWO POSITION
THREE POSITION
INFINITE POSITIONING
33
34
35
CROSS FLOW
FLOW ALLOWED IN EITHER DIRECTION
36
D
D
37
PARALLEL FLOW
FLOW IN ONE DIRECTION
Printed in U.S.A.
© 2003 Caterpillar All Rights Reserved
38
JJ
11
41, 51, 52 41
43
42
44
47
46
45
Chart B 980G Hydraulic Component Locations Item No.
48
49
50
51
53
52
LINE PATTERNS
55
54
Pressure Line 56
Pilot / Load Sensing Pressure Drain / Return Lines
F
F
MM
Component Group 58
57
60
59
Attachment Air Line
61
62
63
64
NN
THIS SCHEMATIC IS FOR THE 980G Part #: 108-0135-05
66
66
G
G
Components are shown installed on a fully operable machine with the key and engine off and transmission shifter in neutral. E95179
1
2
3
49, 53
9
5
E
KK
LL
AA, BB 10
GG
KK
E
1, 4, 16, 27, 30, 32, CC, DD, EE, HH, LL
28
4
5
6
7
8
9
Chart A 980G Hydraulic Pressure Tap Locations Pressure Tap
Description
Schematic Location
AA
Tilt Rod End
BB
Tilt Head End
CC
Lift Head End
DD
Lift Rod End
EE
Brake Pressure
B8
FF
Implement Relief
C1
GG
Implement Return
C5
HH
Pilot Pressure
C3
A4
Component
11
Main Control Valve *
2
Auxiliary Head End Relief Valve
33
Auxiliary Rod End Relief Valve
44
Auxiliary Cylinder
55
Tilt Cylinder #
66 77
Lift Cylinder Ride Control Relief Valve @
8
Ride Control Solenoid Valve @
9
Ride Control Accumulator @
10
Front Service Brakes
11
Rear Service Brakes
Chart B 980G Hydraulic Component Locations Schematic Location
Item No.
Component
Schematic Location D7
34
Pressure Relief Valve
35
Transmission Control Module Pressure Switch
D8
36
Parking Brake
D9
37
Steering Cylinder Port (A)
D6
38
Steering Cylinder Port (B)
D7
39
Pilot/Brake Pump
40
Transmission Pump
41
Cooler Bypass Valve
42
Pilot Valve
43
Check Valve
A7
44
Pilot Port (B)
A1
A2 A3,A4 A5
A6
12
Service Brake Control Valve
A8
45
Steering Valve
13
Ride Control Check Valve @
B5
46
Crossover Relief
14
Tilt Rod End Relief Valve
B3
47
Shuttle Valve
E2
11 E5
E6
Tilt Head End Relief Valve
B4
48
Load Sensing Pump Port
B5
49
Selector Valve
F4
50
Steering Pump
F2
51
Hydraulic Oil Cooler
52
Fan Motor
53
Steering Pilot Oil Shuttle Valve
F4
54
Pilot Port (A)
F6 F7
16
Check Valve Rear Service Brakes Accumulator
18
Front Service Brakes Accumulator
19
Tandem Spool Assembly
20
Accumulator Charging Valve
21
Inverse Shuttle Check Valve
B7 B9 B7
22
Parking Brake Control Valve
B9
55
Makeup Check Valve
Load Sensing Spool
C7
56
Implement Pumps
24
Service Brake Low Oil Presure Switch
57
Breaker Relief Valve
58
Filter Element
F3
59
Supplemental Steering Pump
F4
25
Manually Operated Parking Brake Spool
26
Parking Brake Pressure Spool
C9
56, 61, LL, MM
37, 38, 44, 45, 46, 47, 48, 54, 55, 60, 62, 63, 64
39, 40, 50, JJ
10
6 17, 18
12, 20, 22, 24, 35, FF
7, 8, 13
36
F3
23
C8
42
57, 58, 65
E7
15 17
33
E3
F2
27
Main Relief Valve
C1
60
Backup Relief
F7
28
Ride Control Diverter Valve @
C6
61
Fan Pump
F2
29
Service Brake Oil Pressure Switch
C7
62
Regulated Pressure Port to Pilot Valve
30
Pilot Valve
C6
63
Pressure Reducing Valve
31
Flow Control Valve Group
C7
64
Pump Port
32
Screen
C2
65
Hydraulic Oil Tank
G3
33
Steering Cylinders
D6
66
Diverter Valve
G5
56, 61, LL, MM
41, 51, 52
37, 38, 44, 45, 46, 47, 48, 54, 55, 60, 62, 63, 64 59, 66, NN
39, 40, 50, JJ
KK
42
AA, BB 9
F7
1, 4, 16, 27, 30, 32, CC, DD, EE, HH, LL
36
17, 18
28
5
* The one stem valve is an attachment field conversion. The two stem valve is standard. The three stem valve is the logger attachment. # Available in standard, logger, or high lift configurations.
B5
JJ
Steering Pressure
E1
KK
Oil Cooler Return
E3
LL
Implement Pressure
F1
MM
Steering Relief
F5
NN
Fan Relief
F1
@ Ride Control Attachment
GG 57, 58 33, 49, 53 11
12, 20, 22, 24, 35, FF
65
6 7, 8, 13
10
20 Page, DGM
40
6
33
SENR5884-01
39
59, 66, NN