Component Locations
Tap Locations Pressure and Sampling
Schematic Location
Tap Number
Brake Control System Accumulator Gp - Brake (Charged)
247-8553
1
B-2
Brake Gp - Parking
170-4618
2
C-3
Control Gp - Foot Brake
250-9458
3
B-4
Manifold Gp - Control (Brake Accumulator Charge)
273-8751
4
A-2
164-5486 Front Rear
A-2 C-4
7
A-4
171-7085
8
B-2
Brake Accumulator Charge
175-3244
9
A-2
Parking Brake
174-4312
8
C-2
220-0814
10
A-3
Parking
106-1774
8
B-2
Service
248-7619
11
B-4
6E-5444
12
B-2
Switch As - Limit (Parking Brake) Switch As - Pressure
288-8390
5 6
Valve - Breaker Relief (Hydraulic Tank) Valve Gp - Brake Control Valve Gp - Check
Actuator Gp - Pilot Control (Proportional Solenoid) (Dump)
LH RH LH
Actuator Gp - Pilot Control (Proportional Solenoid) (Lower)
RH Actuator Gp - Pilot Control (Proportional Solenoid) (Rackback)
245-2975
101
217-6720
102
217-6719
LH
217-6719
RH Actuator Gp - Pilot Control (Proportional Solenoid) (Raise)
LH
217-6720
102 102 102
Cylinder Gp - Lift Cylinder Gp - Tilt (Lift Machines, Standard)
C-7
CC
Fan Pump Discharge Pressure
B-5
DD
Implement Pilot Supply Pressure
C-7
EE
Cylinder Tilt Head End Pressure
D-6
FF
Cylinder Tilt Cylinder Rod End Pressure
D-6
GG
Cylinder Lift Head End Pressure
E-7
Cylinder Lift Rod End Pressure
D-7
II
Ride Control Signal Pressure
C-5
JJ
Fan Pump Signal Pressure
A-5
KK
Steering Pilot Supply Pressure
D-2
LL
Steering Pump Discharge Pressure
D-3
MM
Steering Right Cylinder Pressure
F-4
NN
Steering Left Cylinder Pressure
F-4
OO
Steering Signal Accumulator Service Brake Pressure (Front and Rear)
B-3
Service Brake Pressure (Front and Rear)
A-3
D-6
RR SOS
Rear Axle Service Brake Pressure Hydraulic Oil Sampling Port
A-4 A-6
C-6, C-7
SS
Front Axle Service Brake Pressure
C-4
B-8
C-6
TT
Rear Axle Oil Cooler Pump / Motor Pressure
F-8
D-6, D-7
UU
Front Axle Oil Cooler Pump / Motor Pressure
E-8
C-6
VV
Supply Pressure for Axle Cooling
E-8
WW
Brake Accumulator Pressure
A-2
D-6, D-7
SS
MAIN AUX.
PUMP or MOTOR
B-6
LH
308-0831
104
E-5
RH
308-0830
105
E-7
106
E-6
107
E-6
Standard, LH
308-0833
High, LH
308-0837
Standard, RH
308-0832
High, RH
308-0835 155-6061
108
C-8
Manifold Gp - Control (Implement Oil Cooler Bypass Valve)
258-0754
109
B-6
110
B-5
111
B-6
112
A-5
Hydraulic Fan, Standard
159-7166
Hydraulic Fan, High Ambient Temperature Cooling
249-7017 251-6523 249-7016
Hydraulic Fan, High Ambient Temperature Cooling, Note A
249-7014
Pump Gp - Piston (Implement Pilot, Axle Oil Cooling) Pump Gp - Piston (Implement)
249-7013
113
C-8
Center
313-7242
114
B-7
Right Front
313-7239
115
B-8
115
A-8
Right Rear Pump Gp - Piston (Implement, Right Hand, Tandem)
313-7241 313-7240
Sensor Gp - Liquid Level (Implement, Hydraulic Fan Tank)
306-6875
108
A-6
167-1709
116
B-5
Sensor Gp - Pressure (Implement Pilot Pressure)
224-8496
117
B-8
Sensor Gp - Pressure (Implement Pump)
LH RH
221-3405
118
C-6
119
C-6
Sensor Gp - Pressure (Lift Cylinder Head End Pressure)
221-3416
120
E-7
Sensor Gp - Temperature (Ambient Air)
118-7226
108
A-6 C-8
Switch As - Differential Pressure (Implement Pilot Filter Bypass)
156-1382
108
Switch As - Pressure (Filter Bypass)
253-2673
121
A-6
Tank Gp & Filter Gp - Hydraulic (Implement, Hydraulic Fan)
305-4313
122
A-6
Valve - Breaker Relief (Hydraulic Tank)
220-0814
123
A-5
Valve Gp - Blocker (Implement Pump Shutoff)
274-9982
124
A-6
Valve Gp - Check (Implement Pumps, Dual)
275-4180
125
B-7
Valve Gp - Demand Fan (Speed Control)
191-8735
126
A-5
Valve Gp - Main Control (Implement Valve Lift)
LH RH
253-1988 253-1989
102
INFINITE POSITION
127
B-5
Valve Gp - Manual (Coupler Pin Control) (Manual Lower Valve)
112-1817
128
C-7 D-7
Valve Gp - Pressure Reducing
Dead Engine, Lift Arm Lower
185-1897
102
Implement Pilot Oil
160-4128
101
Lift Head End
144-0221
Valve Gp - Relief (Line)
Valve Gp - Relief (Main)
Lift Rod End
129-8293
Tilt Head End
117-0161
Tilt Rod End
172-5481
LH
VENTED
RETURN ABOVE FLUID LEVEL
PRESSURIZED
Valve Gp - Solenoid
102
MEASUREMENT
992K and 993K Wheel Loader Hydraulic System
PP
992K: LWA1-UP
RR
PRESSURE
ROTATING SHAFTS
FLOW
TEMPERATURE
COMBINATION CONTROLS
993K: Z9K1-UP
SOLENOID or MANUAL
SOLENOID
MANUAL SHUTOFF
PUSH-PULL LEVER
GENERAL MANUAL
151-7455
102
C-7
Load Sensing, Float, LH
173-7455
129
C-6
Load Sensing, Float, RH
173-7455
129
C-7
250-8479
201
Cylinder Gp - Steering
288-5504
202
F-4
Filter Gp - Oil (Steering Oil Cooler, Pilot)
115-2129
203
D-1
251-4398
204
D-1
205
D-3
249-7026 306-6875
206 207
D-3 D-2
224-8497
205
E-2
High Ambient Steering Pump, Note B
249-7024
Pump Gp - Piston (Steering, Center) Sensor Gp - Liquid Level (Steering, Brake Hydraulic Tank) Sensor Gp - Pressure
Steering Pilot Oil
Sensor Gp - Temperature Switch As - Pressure
E-2
Steering, Center
221-3406
208
D-3
Steering, LH
221-3406
208
D-2
Steering, Brake Oil
288-8390
209
C-2
210
D-2
Case Drain Filter Bypass Steering Oil Cooler Filter Bypass
253-2673
211
D-1
Tank & Filter Gp - Hydraulic (Steering, Brake)
247-7817
212
D-2
Valve - Breaker Relief (Hydraulic Tank)
220-0814
212
D-1
Valve - Check (Steering Pump)
275-8819
213
D-3
Steering Oil Cooler Bypass
6E-1454
214
E-2
Steering Quad
111-7775
215
E-4
Valve Gp - Pilot (STIC Steering)
249-5615
216
D-4
Valve Gp - Pressure Reducing (Steering Pilot Oil Regulator)
6E-4286
217
E-3
100-4335
217
E-3
Steering Cylinder Crossover
6E-3985
217
F-4
Steering Pilot
224-5741
205
E-1
254-5992
218
F-2
4T-1860
217
F-4
301-4610
217
F-3
146-7571
219
D-4
Valve Gp - Check
Valve Gp - Relief
Pump Backup
Valve Gp - Shuttle Load Signal, Steer, Implement Valve Gp - Steering (Standard - no Secondary Steering) Valve Gp - Steering Neutralizer (HMU Steering)
LH RH
EXTERNAL RETURN
23
245-8354
Core As - Oil Cooler (Axle Oil Cooler)
Rear
104-1817
Filter Gp - Oil (Screen, Axle Oil Cooler)
Front
Pump & Motor Gp - Axle Oil Cooler
Front
Switch As - Pressure (Brake Lube Oil)
Front
Rear Rear Valve - Bypass (Axle Oil Cooler, Thermal Relief)
Front Rear
25
26
230-3633 249-7012 130-7459 251-1635
BRAKE MANIFOLD PRESSURE TAPS
301
3
117
FRONT DIAGNOSTIC PANEL
102
304 UU
119
F-8
303
E-8
304
F-8
305
E-8
306
F-8
305
E-8
301
F-8
307
E-8
307-1997
401
F-5
173-0159
402
F-6
Latch
177-3072
401
F-5
Cylinder Line Relief
272-0740
403
F-5
Main
307-1567
402
F-6
Pump & Motor Gp - Platform (Operator Lift, Electric Drive)
293-8389
404
F-6
Tank Gp - Hydraulic (Operator Lift)
293-2850
402
F-6
Valve Gp - Check (Automatic Lubrication Air Control)
6E-5444
405
F-6
Brake Pump
501
A-2
Hydraulic Fan Motor
502
B-5
Hydraulic Fan Pump
502
B-5
503
B-7
Implement Pump, Right
503
B-7
Secondary Steering Pump
504
E-2
Steering Pump
505
D-3
7
219
RR
UNIDIRECTIONAL
BIDIRECTIONAL
BIDIRECTIONAL
Accumulator Gp - Charged
253-2676
601
C-5
Valve Gp - Makeup
9T-9552
602
C-5
Valve Gp - Shuttle
141-1481
603
C-5
Valve Gp - Solenoid
152-8340
603
C-5
246-9927 6E-3780
Primary Steering Pump when Secondary Steering Present Secondary Steering Pump
Valve - Diverter (Load Sensing, Secondary Steering)
7J-7423 152-6478
701
122 SOS
101
1
PARALLEL FLOW
CROSS FLOW
FLOW ALLOWED IN EITHER DIRECTION
201 G
113
4
210 303
11
Transducer (Fluid)
601 602 604
6 301
110 127 404
502
106
12 405
118
STR-P
PILOT
R-STR
LL
KK
MM
FAN-PUMP
L-STR
CC
NN
IC
LUC
BRK-ACC
6
7
WW
2
8 215 216
504 505
305 JJ
111 112 208 214 126 205
307
124 123 701
115
Pressure Symbol
Electrical Schematic Example
4
11
12
2
10 126 207 218
Harness identification code This example indicates wire 135 in harness "AG".
3 106 107
11
1
116 126
219
113 124 121 SOS 123 122 108
210
FRONT DIAGNOSTIC PANEL
702 702
201
602
5
103
II
601
(6) Control pressure for impeller clutch (7) Control pressure for lockup clutch (9) Transmission lubrication pressure (10) Speed Clutch Pressure Tap P1 (11) Oil Pump Output Pressure Tap (12) Direction Clutch Pressure Tap P2 (13) Torque Converter Inlet Pressure Tap P3
(LL) Steering pressure (KK) Steering pilot pressure (MM) Right steering pump pressure (CC) Fan drive pump pressure (NN) Left steering pump pressure (WW) Brake accumulator pressure
Wire Color
Wire Gauge
Previous Standard Wire Color
Wire
325-PK-14 B
The rear diagnostic lines group is located on the right side of the pump compartment behind the cab.
Circuit Number Identification
110
(EXAMPLE VALVE)
REAR REMOTE DIAGNOSTIC STATION
Remote Taps
125 303 401
DD
GG
EE
PILOT SUPPLY (8)
LIFT HEAD (5)
TILT HEAD (6)
12 127 404 405 4
2
701
212
502
F-3 F-2
6E-3986
702
E-2
6E-3078
702
E-3
Valve Gp - Steering (with Secondary Steering)
301-4612
702
F-3
A
Wire Gauge
403
120 129
E-2
Valve Gp - Selector & Pressure Control (Secondary Steering)
Wire Color
325-PK
102
118 120 503
Wire
325-AG135 PK-14
216 REAR DIAGNOSTIC PANEL
Hydraulic Schematic Example Current Standard
208 213 214
117 203 211
Flow Symbol
Circuit Number Identification
Circuit Identification Number
119 215 501 504
Level Symbol
Current Standard
3
8
Temperature Symbol
Wire Number Identification Codes
217 402 702
114 204 206 213 SS
Electrical Wire
Temperature Switch
1
13
BRAKE MANIFOLD
Electric Motor
T
10
116
Generator
Electrical Symbols (Electrical)
LUBE-IN
401 403
218 203
Pressure Switch (Adjustable)
Pressure Switch
9
104
Transducer (Gas / Air)
II
603
306
M
103 109
107
E-3
Valve Gp - Relief (Secondary Steering)
Note A: Tandem to Steering Pump (Machine Location 205)
FLOW IN ONE DIRECTION
TWO POSITION
THREE POSITION
INFINITE POSITIONING
Printed in U.S.A.
HH
FF
LIFT ROD (3)
TILT ROD (4)
VV
BB
AA
AXLE MOTOR SUPPLY (7)
RIGHT VALVE SUPPLY (1)
LEFT VALVE SUPPLY (2)
Secondary Steering Attachment Valve - Check
INTERNAL PASSAGEWAYS
Hydraulic Symbols (Electrical)
Ride Control Attachment
Pump Gp - Gear (Secondary Steering)
VARIABLE DISPLACEMENT NON-COMPENSATED
DOUBLE ACTING
Electrical Symbols Table
High Pressure - Deluxe Filtration Attachment
174-4502
FIXED DISPLACEMENT
UNIDIRECTIONAL
BRAKE MANIFOLD
9 501 202
129 125
105
120 302 503
128
E-8
302
Filter Gp - Oil (Ultra High Efficiency, Hydraulic)
Implement Pump, Center
SINGLE ACTING
5 108 121 124
REAR DIAGNOSTIC PANEL
F-8
Cylinder Gp - Platform (Operator Lift)
Screen Gp - High Pressure
LINES JOINING
© 2009 Caterpillar All Rights Reserved
FRONT and REAR AXLE PRESSURE TAPS
Operator Lift Arrangement
Manifold Gp - Control (Operator Lift)
HYDRAULIC AND PNEUMATIC CYLINDERS
HYDRAULIC MOTORS
VARIABLE DISPLACEMENT NON-COMPENSATED
INTERNAL SUPPLY PRESSURE
COMPLETE
REAR AXLE: (RR) Pressure port for the rear service brakes.
10 126 207 209 210 212 TT
Front
Rear
24
The brake manifold is located at the font of the cab on the underside of the cab.
Axle Oil Cooler Arrangement Core As - Oil Cooler (Axle Oil Cooler) (Core Gp)
LINES CROSSING
SPRING
REMOTE SUPPLY PRESSURE
CROSSING AND JOINING LINES
GAS CHARGED
FIXED DISPLACEMENT
PEDAL
SIMPLIFIED
HYDRAULIC PUMPS
(23) Pressure port for the rear service brakes (24) Pressure port for the front service brakes (25) Pressure port for the accumulator for the front service brakes (26) Pressure port for the accumulator for the rear service brakes
PUSH BUTTON
INTERNAL RETURN
SPRING LOADED
D-6
Steering and Cooling Control System
251-6516
DETENT
THERMAL
PILOT CONTROL SYMBOLS
RELEASED PRESSURE
D-6
Hydraulic Lockout, Pilot On/Off
Standard, Steering Pump
SERVO
SOLENOID and PILOT or MANUAL
SOLENOID and PILOT
D-7
D-7
Pump Gp - Gear (Steering, Oil Cooler)
BIDIRECTIONAL
MANUAL CONTROL SYMBOLS
D-6
102
Pump Gp - Piston
UNIDIRECTIONAL
D-7
4T-1860
Core As - Steering Oil Cooler
RETURN BELOW FLUID LEVEL
C-8
102
RH
PILOT CONTROLLED
D-7
253-1991
Valve Gp - Shuttle (Load Signal, Steer, Implement)
SHUTTLE
SPRING LOADED
BASIC SYMBOL
FLUID STORAGE RESERVOIRS
FRONT AXLE: (SS) Pressure port for the front service brakes.
D-7
187-2715
FOUR-WAY
THREE-WAY
CHECK VALVES
P T SHIFTED POSITION
P T NORMAL POSITION
D-5
Valve Gp - Makeup (Hydraulic Fan Motor)
TWO-WAY
AB
ACCUMULATORS
Sensor Gp - Pressure (Hydraulic Fan Pump Oil, Discharge Pressure)
ATTACHMENT
LINE RESTRICTION VARIABLE and PRESSURE COMPENSATED
VALVE PORTS
CONTROL VALVES AB
Pump Gp - Piston Hydraulic Fan, Standard Temperature Cooling
HYDRAULIC PNEUMATIC ENERGY TRIANGLES
THREE POSITION
PUMP: VARIABLE and PRESSURE COMPENSATED
2-SECTION PUMP
VALVES
TWO POSITION
ONE POSITION
LINE RESTRICTION (FIXED)
RESTRICTION
PRESSURE COMPENSATION
LINE RESTRICTION (VARIABLE)
SPRING (ADJUSTABLE)
VALVE ENVELOPES
D-6
103
CONTROL VALVES
SPRING
FLUID CONDITIONER
VARIABILITY
D-3
PP
250-8480
Pump Gp - Gear (Implement Cooler, Standard Temperature Cooling)
C-6
Implement Right Hand Relief Pump Pressure
Filter Gp - Oil (Axle Oil Cooler) Motor Gp - Piston
Implement Center Relief Pump Pressure
BB
FLUID POWER SYMBOLS BASIC COMPONENT SYMBOLS
C-6, C-7
RH Core As - Hydraulic Oil Cooler (Implement Air to Oil Cooler)
Description
AA
HH
Implement Control System Accumulator Gp - Pilot Oil (Charged)
Schematic Location
301 302
6
9
304 UU
202
101 111
307
217 402 702
128 209 210 505
305 TT
7 208 RR 112 114 115 204 205 206 JJ OO SS
Note B: Tandem to Hydraulic Fan, Implement Oil Cooling Pump (Machine Location 112)
MACHINE COMPONENTS
(DD) Pilot Supply Pressure (GG) Head end pressure for lift cylinder (EE) Head end pressure for tilt cylinder (HH) Rod end pressure for lift cylinder (FF) Rod end pressure for tilt cylinder (VV) Supply pressure for axle cooling (BB) Implement supply pressure to right main control valve (AA) Implement supply pressure to left main control valve
109 603 MANUAL LOWER VALVE
104 105 306
Pressure Taps
FRONT REMOTE DIAGNOSTIC STATION
The front diagnostic lines group is located on the right side of the articulation hitch.
(Dimensions: 39 inches x 28 inches)
Pump Gp - Piston (Brake) Sensor Gp - Temperature (Axle Oil)
KENR5829-02 November 2009
30 Page,
Description
Machine Location
KENR5829-02
Part Number