 |
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 |
|---|
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, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products. Dispose of all fluids according to local regulations and mandates. |
Specification
| Parking Brake Pressure - Test | ||
| Date | Equipment ID Code | |
| Description | Specification | Actual |
| Parking Brake with Engine Off Switch ON | Less than 690 kPa (100 psi) | |
| Parking Brake with Engine Running and Switch ON | 690 kPa (100 psi) |
|
| Parking Brake with Engine Running and Switch OFF | 3620 ± 345 kPa (525 ± 50 psi) |
|
Introduction
This procedure checks the parking brake pressure at the front and rear wheels.
Required Tools
 | |
| Illustration 1 | g01623868 |
Tooling (B) | |
| Tool | Item | Part Number | Description | Qty |
|---|---|---|---|---|
| B | 198-4240 | Digital Pressure Indicator Gp | ||
| B1 | 198-4234 | Digital Indicator | 1 | |
| B2 | 251-9600 | Pressure Sensor Gp (0 to 68,900 kPa (0 to 10,000 psi)) | 2 | |
| B3 | 198-4236 | Adapter Cable As | 2 | |
Machine Preparation
- Run the machine in order to reach the normal operating temperature.
- Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel. Place the transmission direction control switch in the NEUTRAL position. Engage the parking brake. Lower the bowl to the ground. Stop the engine and put chocks in front of the wheels and behind the wheels.
- Use a suitable lifting device to support the section of the belly pan that has an access port. Then remove the belly pan and move the belly pan out of the way.
Note: The weight of the belly pan is 98.8 kg (218 lb).
 | |
| Illustration 2 | g03397549 |
View of the portion of the belly pan that has the access port | |
- The area that is involved in this procedure has been exposed.
 | |
| Illustration 3 | g03397569 |
The arrow shows the location of the manifold | |
- Connect (B) to (1) or (2) in order to check the parking brakes.
Note: Either of these pressure tap locations will check both the front and rear parking brakes.
 | |
| Illustration 4 | g03866902 |
Optional connecting location above the manifold for the hydraulic fan and brake manifold. | |
 | |
| Illustration 5 | g02635157 |
Optional connecting Location on the rear of the scraper. Rear of scraper near ejector cylinder. | |
Test Procedure
- Start the engine and allow the engine until cut-out pressure is reached. Move the parking brake control switch to the OFF position.
- Shut off the engine.
- With the engine off place the parking brake switch to the ON position. The parking brake pressure should be less than 690 kPa (100 psi).
- Return the parking brake switch back to the OFF position.
- Start the engine.
- With the engine running at low idle shift the parking brake switch to the ON position. The parking brake pressure shall be 690 kPa (100 psi).
- With the engine running at low idle shift the parking brake switch to the OFF position. The parking brake pressure shall be 3620 ± 345 kPa (525 ± 50 psi). Refer to the Adjust Procedure of this article if the pressure reading is incorrect.
Adjust Procedure
 | |
| Illustration 6 | g03397531 |
- Shut of the engine.
- Hold the stem on pressure reducing valve (3) and loosen locknut (4) .
- Then turn the adjustment stem using a maximum of 1/4 turn intervals.
- Hold the stem on pressure reducing valve (3) and tighten lock nut (4) .
- Start the engine. With the engine running at low idle shift the parking brake switch to the OFF position. The parking brake pressure shall be 3620 ± 345 kPa (525 ± 50 psi). Perform this Adjust Procedure until the setting is correct.
If the Parking Brake Pressure Test Results Are not to Standard
- Check the accumulator pre-charges by referring to the Testing and Adjusting, "Brake Accumulator (Service) - Test and Charge" in this book. The story provides information regarding the charging values based on temperature.
- Purge the brakes thoroughly by referring to the Testing and Adjusting, "Parking Brake Purge Procedure" in this book. This story provides information regarding the purge procedure for your machine.
- Check the accumulator pressures at the test ports on the fan and brake block. Refer to Testing and Adjusting, "Brake Accumulator Charging Valve - Test"in this book. This story provides information regarding the Brake Accumulator Charging Valve for your machine.