RENR8824-01 October 2011
Component Locations Part Number
Machine Location
Schematic Location
Accumulator Gp - Brake (Charged)
219-2949
1
B-7, C-7
Accumulator Gp - Pilot Oil (Charged)
226-0420
2
D-8
Adapter As
164-5633
3
F-6
Core As - Hydraulic Oil Cooler (Hydraulic Fan, Steering)
191-4600
4
C-11
Core As - Hydraulic Oil Cooler (Implement / Brake Supply)
261-3853
5
B-5
Cylinder Gp - Lift
9T-9569
6
H-3, H-4
Cylinder Gp - Lift (High Lift)
4Z-6390
7
H-3, H-4
Cylinder Gp - Steering (Left)
6E-1244
8
G-14
Cylinder Gp - Steering (Right)
9T-9568
9
G-14
Cylinder Gp - Tilt
251-1490
10
G-4
Cylinder Gp - Tilt (High Lift)
252-5213
11
G-4
Elbow - (Orificed)
127-9015
12
C-10
Filter Element As - Oil (Hydraulic) (Implement Tank)
4T-3134
13
B-5
Filter Element As - Oil (Hydraulic) (Steering Tank)
4T-3134
14
B-11
Filter Gp - Oil (Hydraulic Fan Motor Case Drain)
166-4647
15
C-11
Filter Gp - Oil (Hydraulic Fan Pump Case Drain)
166-4647
16
B-11
Filter Gp - Oil (Implement Pump Case Drain)
166-4647
17
A-4
Filter Gp - Oil (Steering Pump Case Drain)
166-4647
18
B-12
6V-3965
19
B-13 C-12
Motor Gp - Piston (Hydraulic Fan)
229-0100
20
D-10
Pump Gp - Gear (Pilot, Brake)
230-0914
21
B-7
Pump Gp - Piston (Hydraulic Fan) (Std, Mid Range Ambient Temperature) (High Ambient Temperature)
229-0099 235-0843
22 23
B-11
Pump Gp - Piston (Steering)
229-8604
24
B-12
Pump Gp - Piston (Tandem, Implement)
229-8602
25
B-4
Screen As (Hydraulic Tank)
9T-9227
26
B-11
Screen Gp
7J-2656
27
B-11
Tank & Filter Gp - Hydraulic (Hydraulic Fan, Steering)
6E-4683
28
B-12
Tank & Filter Gp - Hydraulic (Implement, Brake)
237-4228
29
B-5
Valve - Breaker Relief (Implement, Brake Tank)
133-1963
30
B-5
Valve - Breaker Relief (Steering, Hydraulic Fan Tank)
133-1963
31
B-11
Valve - Fluid Sampling (Steering, Hydraulic Fan Oil)
8C-3446
32
C-11
Valve (Filter Bypass)
9J-1988
33
B-11
Valve Gp - Check (Brake Oil Cooler Bypass)
6E-1454
34
C-11
Valve Gp - Check (Pilot)
9T-3096
35
G-4
Valve Gp - Check (Steering Quad)
104-7108
36
C-13
Valve Gp - Check (Steering Quad)
111-7775
37
D-14
Valve Gp - Combination (Pilot, Brake)
9T-9551
38
D-7
Valve Gp - Demand Fan
191-8735
39
C-9
Valve Gp - Main Control (2-Function)
270-1647
40
B-5
Valve Gp - Manifold & Relief (Main)
229-8721
41
B-3
Valve Gp - Pilot (2-Function)
177-4104
42
H-6
Valve Gp - Pilot (Stic Steering)
249-5615
43
B-15
Valve Gp - Pressure Reducing (Lowering Control)
6E-4286
44
D-13
Valve Gp - Relief (Brake System Backup)
234-0351
45
B-7
Valve Gp - Relief (Line, Lift Head End)
142-4281
46
C-4
Valve Gp - Relief (Line, Tilt Head End)
9T-6720
47
D-4
Valve Gp - Relief (Line, Tilt Rod End)
6E-3185
48
D-4
Valve Gp - Relief (Main)
143-8912
49
B-4
Valve Gp - Relief (Main)
4Z-6240
50
B-4
Valve Gp - Relief (Pilot)
6E-6293
51
C-7
Valve Gp - Relief (Pump Backup)
100-4335
52
E-13
Valve Gp - Relief (Steering Cylinder Crossover)
6E-3985
53
F-15
Valve Gp - Selector & Pressure Control (Dead Engine, Lift Arm Lower)
6E-3078
54
F-5
Valve Gp - Selector & Pressure Control (Steering)
6E-5566
55
C-13
Valve Gp - Shuttle
6R-0442
56
C-7
Valve Gp - Shuttle (Lift Cylinder)
4T-1860
57
F-4
Valve Gp - Shuttle (Load Signal, Steering, Implement) Valve Gp - Steering (Std)
4T-1860 6E-2925
58 59
Valve Gp - Steering Neutralizer (Stic Steering)
9T-7426
60
F-13 C-15
Valve Gp - Unloading
117-7761
61
C-7
BB AA 44 52 53 55 56 12
BASIC COMPONENT SYMBOLS
59 102 103 104 105 106 58
FF GG NN
60 37
28 30 13 22 23
16 39
8 101
21
PUMP OR MOTOR
FLUID CONDITIONER
SPRING
CONTROL VALVES
VARIABILITY
SPRING (ADJUSTABLE)
LINE RESTRICTION (VARIABLE)
PRESSURE COMPENSATION
201
43
6
50 54 57 202
7
PUMP (2 - SECTION)
PUMP (VARIABLE & PRESSURE COMPENSATED)
10 11
34
ONE POSITION
HYDRAULIC PNEUMATIC ENERGY TRIANGLES
TWO POSITION
JJ KK
ATTACHMENT
VALVE PORTS
THREE POSITION
TWO - WAY
THREE - WAY
CONTROL VALVES AB
LINE RESTRICTION (VARIABLE & PRESSURE COMPENSATED)
FOUR - WAY
CHECK VALVES
A B
P T
P T
NORMAL POSITION
SHIFTED POSITION
BASIC SYMBOL
INFINITE POSITION
4
SHUTTLE
SPRING LOADED
PILOT CONTROLLED
FLUID STORAGE RESERVOIRS
990H Series II Wheel Loader Tier 3 Hydraulic System
20
PRESSURIZED
VENTED
RETURN ABOVE FLUID LEVEL
RETURN BELOW FLUID LEVEL
MEASUREMENT
PRESSURE
ROTATING SHAFTS
TEMPERATURE
UNIDIRECTIONAL
FLOW
BWX1-UP
BIDIRECTIONAL
COMBINATION CONTROLS
15 SOLENOID
SOLENOID OR MANUAL
SOLENOID & PILOT
SOLENOID & PILOT OR MANUAL
SERVO
THERMAL
DETENT
MANUAL CONTROL SYMBOLS
5 MANUAL SHUTOFF
PUSH - PULL LEVER
GENERAL MANUAL
17b
17a 19e
25
9
45
1
201
42
6
7
3
LL MM
II
38 51 56
14 29 26
40
EXTERNAL RETURN
INTERNAL RETURN
9 17a
SPRING LOADED
GAS CHARGED
2
58 61
31 33 27
FIXED DISPLACEMENT
13 14 26 27 28 29 30 HH
61 58 56 51 45 38 33 31
© 2011 Caterpillar, All Rights Reserved
COMPLETE
VARIABLE DISPLACEMENT NON-COMPENSATED
FIXED DISPLACEMENT
SINGLE ACTING
LINES JOINING
UNIDIRECTIONAL
BIDIRECTIONAL
BIDIRECTIONAL
DOUBLE ACTING
INTERNAL PASSAGEWAYS INFINITE POSITIONING
VARIABLE DISPLACEMENT NON-COMPENSATED
UNIDIRECTIONAL
INTERNAL SUPPLY PRESSURE
HYDRAULIC & PNEUMATIC CYLINDERS
HYDRAULIC MOTORS
HYDRAULIC PUMPS
HH 2
SIMPLIFIED
LINES CROSSING
SPRING
REMOTE SUPPLY PRESSURE
CROSSING & JOINING LINES
ACCUMULATORS
46 47 48
PEDAL
PILOT CONTROL SYMBOLS
RELEASED PRESSURE
18 19f
PUSH BUTTON
3 POSITION
FLOW IN ONE DIRECTION
PARALLEL FLOW
CROSS FLOW
101
Valve (Primary Steering Pump Check) (Secondary Steering)
6E-3780
102
Valve - Diverter (Secondary Steering)
2U-7345
103
F-12
Valve Gp - Relief (Secondary Steering)
6E-3986
104
E-12
Valve Gp - Selector & Pressure Control (Secondary Steering)
6E-5566
105
C-13
Valve Gp - Steering (with Secondary Steering)
6E-2923
106
F-13
Printed in U.S.A.
II
EE 23 39 DD
ELECTRICAL SYMBOLS TABLE
D-12 F-12
22 17a 16 CC
12 18 19f
42 43
1
37 60
35 54 57 202 203 NN
201
Valve Gp - Control
9T-9552
202
D-2
152-8340
203
D-2
G
M
TRANSDUCER (FLUID)
TRANSDUCER (GAS / AIR)
GENERATOR
ELECTRIC MOTOR
PRESSURE SWITCH
PRESSURE SWITCH (ADJUSTABLE)
TEMPERATURE SWITCH
ELECTRICAL WIRE
FF GG
E-2
Valve Gp - Solenoid
HYDRAULIC SYMBOLS (ELECTRICAL)
10 11 JJ KK
Ride Control
5
41 49 50
4 3
Tap Locations Pressure, Sampling, and Sensor Description
FLOW IN EITHER DIRECTION
Schematic Location
AA
Steer Pilot Supply Pressure Tap
BB
Steer Pump Cutoff
CC
Fan Pump Cutoff
D-7
DD
Fan Pump Discharge Pressure Tap
C-5
EE
Fan Pump Signal Pressure Tap
D-13
FF
Implement Relief - Front Pump Pressure Tap
I-2
6
7
40
ELECTRICAL SYMBOLS (ELECTRICAL)
46 47 48
T
D-8 B-10
GG
Implement Relief - Relief Rear Pressure Tap
G-2
HH
Brake Accumulator
D-8
II
Implement Pilot Supply
B-10
JJ
Tilt Cylinder - Head End
D-7
KK
Tilt Cylinder - Rod End
C-5
LL
Lift Cylinder - Head End
D-13
MM
Lift Cylinder - Rod End
I-2
NN
Ride Control Signal
G-2
LL MM
PRESSURE SWITCH
TEMPERATURE SWITCH
LEVEL SWITCH
FLOW SWITCH
WIRE NUMBER IDENTIFICATION CODES
20 15
34
25
20
17b 19e
8
9
101
201
ELECTRICAL SCHEMATIC EXAMPLE
HYDRAULIC SCHEMATIC EXAMPLE
CURRENT STANDARD
CURRENT STANDARD
HARNESS IDENTIFICATION CODE THIS EXAMPLE INDICATES WIRE 135 IN HARNESS “AG” WIRE CIRCUIT NUMBER IDENTIFICATION
325-AG135 PK-14
CIRCUIT NUMBER IDENTIFICATION
44 52 53 26 55 56 BB AA 59 102 103 104 105 106
WIRE COLOR
WIRE GAUGE
325-PK
PREVIOUS STANDARD WIRE
WIRE COLOR
B
325-PK-14
MACHINE COMPONENT LOCATIONS
WIRE COLOR
CIRCUIT NUMBER IDENTIFICATION
WIRE GAUGE
A
(EXAMPLE VALVE)
(Dimensions: 39 inches x 24 inches)
101-4007
Tap Number
2 POSITION
F-14
Pump Gp - Gear (Secondary Steering)
219-7981
LINE RESTRICTION (FIXED)
VALVES
VALVE ENVELOPES
Attachments (Secondary Steering)
Accumulator Gp - Ride Control (Charged)
RESTRICTION
AUX
35 41 49 203
CC DD EE 24
MAIN
20 Page,
Fitting As (Quick Disconnect)
FLUID POWER SYMBOLS
RENR8824-01
Description