| Required Tools | |||
| Tool | Part Number | Part Description | Qty |
| A | Test Gauge Hose | ||
| 6V-4143 | Coupler (1) | 2 | |
| 6V-3079 | Hose Assembly (1) | 1 | |
| 6V-3966 | Fitting (1) | 1 | |
| B | Test Gauge | ||
| 8T-0852 | Pressure Gauge (2) | 1 | |
| ( 1 ) | Part of 1U-5482 Pressure Adapter Group |
| ( 2 ) | Part of 1U-5481 Pressure Gauge Group |
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Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak. |
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| NOTICE |
|---|
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. |
Machine Preparation
Prepare the machine for testing by completing the procedure that is specified in the Service Manual module Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.
Testing Procedure
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| Illustration 1 | g00485493 |
Location of the Brake Components (1) Pressure tap for the service brake system. (2) Parking brake control valve. | |
The operator's cab and the platform have been removed for clarity in this view.
- Attach the correct hose to pressure tap (1). Use the correct pressure gauge.
- Start the engine and allow the accumulator oil pressure to increase to the cut-in pressure.
Note: Keep the engine running. Allow the accumulator oil pressure to reach cut-out pressure of 14485 ± 345 kPa (2100 ± 50 psi).
- The parking brake control knob needs to be in the disengaged position. The parking brake control knob should be pushed in all the way. Stop the engine.
- Push the brake pedal rapidly several times until the parking brake control knob automatically moves to the engaged position. The parking brake control knob will move outward all the way.
- Read the oil pressure on the gauge.
- The correct hydraulic oil pressure should be 6035 ± 515 kPa (875 ± 75 psi). This will automatically engage the parking brake. If the pressure on the gauge is not correct, the operation of the parking brake control valve is not correct.
- Inspect the parking brake control valve for worn parts or damaged parts. Replace the valve, if these types of problems exist. Recheck using steps 2 through 6.
- Remove the test equipment.