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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. |
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Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. 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 Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products. Dispose of all fluids according to local regulations and mandates. |
The following procedure is designed to check the differential lock for worn seals or damaged seals. This procedure can be used to check the front differential lock and the rear differential lock.
Before you start the test procedure, perform the following procedure.
- Machine Preparation for Troubleshooting
Reference: For more information on preparing the machine for troubleshooting, refer to the Service Manual module for the power train Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.
- Lower the work tool to the ground.
- Engage the parking brake.
- Stop the engine.
- Move the control levers and the foot pedals through the full range of travel. This will relieve any pressure that may be present in the hydraulic system. Move the hydraulic lever lock to the LOCKED position.
- Press the breaker relief valve that is located on the hydraulic tank in order to relieve the hydraulic tank pressure.
- Install the steering frame lock.
- Remove the cover from the right side of the machine.
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| Illustration 1 | g00863563 |
- Repeat Step 7 on the left side of the machine.
- Remove two wing nuts (2).
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| Illustration 2 | g00906593 |
Screen Assembly | |
- Lift up on sliding bar (3) .
- Remove screen assembly (1) by sliding screen assembly (1) to the left side of the machine.
Note: The screen assembly (1) consists of two separate pieces.
- Remove four bolts (5) and screen (4) .
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| Illustration 3 | g00906573 |
- Disconnect the hydraulic line that is connected to pressure tap (6). This hydraulic line is connected to the differential lock on the rear axle.
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| Illustration 4 | g00906574 |
Location of Combination Valve (6) Pressure tap for rear differential lock. (7) Pressure tap for front differential lock. | |
- Install the 2000 kPa (300 psi) pressure gauge (8) and valve (9) onto the hydraulic line that was disconnected.
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| Illustration 5 | g00906577 |
Typical Example (8) Pressure gauge. (9) Valve. | |
- Connect air line to valve (9). Pressurize the differential lock to 700 ± 150 kPa (100 ± 20 psi).
Note: The pneumatic system that is used for the leak test should be free of moisture.
- Turn the valve OFF and disconnect the air line.
- Observe the gauge for one minute.
- If the pressure drops 7 kPa (1.0 psi) in one minute, the seals in the rear differential lock are worn or damaged. Replace the seals.
- If the pressure does not drop then remove gauge. Reconnect the hydraulic line to pressure tap (6) .
- Disconnect the hydraulic line that is connected to pressure tap (7). This hydraulic line is connected to the differential lock on the front axle.
- Install the 2000 kPa (300 psi) pressure gauge (8) and valve (9) onto the hydraulic line that was disconnected.
- Connect air line to valve (9). Pressurize the differential lock to 700 ± 150 kPa (100 ± 20 psi).
Note: The pneumatic system that is used for the leak test should be free of moisture.
- Turn the valve OFF and disconnect the air line.
- Observe the gauge for one minute.
- If the pressure drops 7 kPa (1.0 psi) in one minute, the seals in the front differential lock are worn or damaged. Replace the seals.
- If the pressure does not drop then remove gauge. Connect the hydraulic line to pressure tap (7) .
- Install the screens and the covers.