Usage:
CONFIDENTIAL TIBU2423-01
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TECHNICAL INFORMATION BULLETIN |
May 29, 2002 |
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Wheel Loader |
980G (2KR1-Up, 2SR1-Up, 9CM1-Up) |
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Component Code(s) 5056 5057 5059 |
SUBJECT: HYDRAULIC SYSTEM MAY PULSATE WHEN THE MACHINE IS AT LOW IDLE AND THE LIFT ARM LOWER FUNCTION IS IN THE "FLOAT" POSITION
PROBLEM: Some machines listed are experiencing hydraulic pulsations. This is occurring when the machined is at low idle and the lift arm lower function is in the "Float" position.
NOTE: The pulsation is more common on machines equipped with a third valve.
SOLUTION: First, verify that the low idle and pilot pressure settings are within the following specifications.
Low Idle: 800 ? 30 rpm
Pilot Pressure: 3445 ? 206 kPa (500 ? 30 psi)
If the low idle and pilot pressures are within specification, the installation of an additional drain line from the pilot valve to the tank may be necessary. Use the following procedure in order to install the additional drain line.
Installation Procedure
Parts List |
||
Quantity |
Part Number |
Description |
1 |
3J-1907 |
O-Ring Seal |
3 |
6V-8397 |
O-Ring Seal |
2 |
6V8398 |
O-Ring Seal |
1 |
6V-8936 |
Reducer Assembly |
1 |
6V-9837 |
Tee-Swivel |
1 |
6V-9850 |
Elbow |
1 |
8T-0075 |
Connector |
1 |
125-0810 |
Hose Assembly |
Personal injury or death can result without releasing all of the hydraulic oil pressure.
Release all of the pressure from the hydraulic system before any lines are disconnected.
Sudden movement or accidental staring of the machine can cause personal injury or death to persons on or near the machine.
To prevent personal injury or death, perform the following:
Park the machine on a smooth, level surface.
Lower the bucket and/or attachments to the ground and engage the parking brake.
Stop the engine and remove the key.
Block the wheels and install the steering frame lock.
NOTICE
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.
Refer to Special Publication, NENG2500, "Caterpillar Tool and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar Machines.
Dispose of all fluids according to local regulations and mandates.
- Disconnect 145-6129 Hose Assembly (1) from 6V-9837 Tee (2).
- Install one 6V-9837 Tee (6) with one 6V-8393 O-Ring Seal onto 6V-9837 Tee (2).
- Connect 145-6129 Hose Assembly (1) to 6V-9837 Tee (6).
- Install one 6V-8936 Reducer Assembly (3) with one 6V-8398 O-Ring Seal onto 6V-9837 Tee (6).
- Install one 6V-9850 Elbow (4) with one 6V-8397 O-Ring Seal onto 6V-8936 Reducer Assembly (3).
- Connect 125-0810 Hose Assembly (5) to 6V-9850 Elbow (4).
- Connect the opposite end of 125-0810 Hose Assembly (5) to the pilot valve group at port (A) with one 8T-0075 Connector and one 3J-1907 Seal.
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ALL RIGHTS RESERVED