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Personal injury or death can result if two persons are not used in the following procedure. |
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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the brake system. |
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| NOTICE |
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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 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 Tools 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. |
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| Illustration 1 | g00477429 |
The location of the air purge screws that are on the front axle housing. | |
There are two air purge screws that are located on the top of each axle housing.
- Check the hydraulic tank oil level. Make sure that you maintain the correct oil level in the hydraulic oil tank throughout the air removal procedure.
Note: Perform this procedure for one service brake at a time.
- Start the engine. Allow the oil pressure to increase to the cut-out pressure, which is greater than 13100 kPa (1900 psi). Then, stop the engine.
- Fasten one end of a transparent tube that is 6.4 mm (.25 inch) in diameter to an air purge screw. Put the other end of the tube into a suitable container for collecting the hydraulic oil. Loosen the air purge screw.
- The operator should slowly depress the brake pedal. Hold the brake pedal in this position throughout Step 5.
- As the hydraulic oil flows through the tube, look for air bubbles in the oil. Allow the oil to flow into the container until no air bubbles are visible. Then, tighten the air purge screw. Release the brake pedal.
- Perform this procedure for each of the other service brakes. Make sure that you tighten each air purge screw.
- Check the hydraulic oil tank level.
- Fill the hydraulic tank, if necessary.
Note: If the brake pedal is spongy perform this procedure again.