Personal injury or death can result if two persons are not used in the following procedure. |
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. |
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. |
Illustration 1 | g00460835 |
(1) Inspection plugs for the front axle (typical location). |
Illustration 2 | g00460836 |
(1) Inspection plugs for the rear axle (typical location). |
Illustration 3 | g00460838 |
Service Brake Disc (A) Thickness of disc. (2) Plate. (3) Disc. (4) Piston. |
Each axle has two threaded plugs that are used for inspecting the corresponding brake disc. Inspection plugs (1) are located on the front of the front axle and on the rear of the rear axle. The procedure to check the front brake discs for wear is identical for the rear brake discs.
- Position the machine on level ground. Stop the engine. Engage the parking brake.
- Lower the oil level in the axle housing below inspection plugs (1) .
- Remove the inspection plug for the brake disc that is being checked.
Note: For high speed machines, oscillating the rear axle provides access to the inspection plugs.
Note: The service brake system is equipped with a separate hydraulic oil reservoir. Therefore, the service brakes can be applied without running the engine. However, applying the service brakes may be difficult without the assistance of the brake boost. If applying the service brakes is too difficult, move the directional control lever to the NEUTRAL position. Engage the parking brake. Place wheel chocks in front of each wheel and behind each wheel. Start the engine.
- Hold down either brake pedal. This will hold piston (2) , brake disc (3) and plate (4) together.
- Use a feeler gauge to measure the thickness of brake disc (3) .
Minimum disc thickness (A) is 6.11 mm (0.241 inch). Thickness of a new brake disc is 7.09 mm (0.279 inch). Replace the brake disc before disc thickness (A) is less than 6.11 mm (0.241 inch) .
- Use a depth gauge to measure the depth of the oil grooves on both sides of the brake disc in each axle housing. The depth of the oil grooves cannot be less than 0.32 mm (.013 inch) .
Illustration 4 | g00110142 |
Oil Groove Depth of the Brake Discs |
Note: The oil groove depth is the most critical dimension. If the depth of the oil grooves on the brake discs is too shallow, oil flow will be inadequate. This can cause excessive wear and abrasion.
- Install the inspection plugs and fill the axle housing to the correct oil level.