Note: The brake assembly may not engage correctly if the air gap is set incorrectly. When a new brake disc assembly is installed in the axle, the air gap should be checked. If the air gap is out-of-range, adjust the air gap by adjusting the stroke of the brake cylinder.
| 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 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. |
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| Illustration 1 | g00923728 |
(1) Plug (oil filler). (2) Dipstick. (3) Plug (brake wear). (4) Plug (breather and brake wear). (5) Brake cylinders. | |
The wear of the brake discs can be checked while the axles are on the machine or while the axles are removed from the machine.
- Place wheel chocks in front of the tires and behind the tires in order to ensure that the machine will not move.
- Remove plug (3) and plug (4) .
- Disconnect the hose assembly from parking brake port (9) .
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| Illustration 2 | g00933310 |
(3) Plug. (6) Port for brake disc wear check. (7) Ball and ramp mechanism. (8) Cap. (9) Parking brake port. | |
- Remove cap (8) .
- Manually disengage the parking brake cylinder.
Note: A bolt is stored under cap (8) .
- Install bolt (11). Tighten bolt (11) until the spring that is inside of the parking brake cylinder is completely compressed. The spring that is inside of the parking brake cylinder is completely compressed when bolt (11) cannot be turned.
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| Illustration 3 | g00933316 |
(10) Bolt. (11) Bolt. (12) Bolt. (13) Housing. | |
- Remove four bolts (12) .
Note: Do not remove two bolts (10) .
- Remove housing (13) .
- Loosen adjusting nut (15). In order to loosen adjusting nut (15), pressure piston (16) must be secured in place.
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| Illustration 4 | g00933318 |
(14) Adjustment bolt. (15) Adjustment nut. | |
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| Illustration 5 | g00933321 |
(14) Adjustment bolt. (15) Adjustment nut. (16) Pressure piston. (17) Wedge. | |
- Remove bolt (14). Be sure to clean all of the dirt and oil from the threads of bolt (14) and adjusting nut (15).
- Screw on adjusting nut (15) up to the head of bolt (14) .
- In order to engage the brake, install bolt (14) into pressure piston (16) and torque bolt (14) to 13.5 ± 1.5 N·m (120 ± 13 lb in). This will engage the brake by forcing wedge (17) toward the center and expanding the washers in ball and ramp mechanism (7). The washers will press the brake discs toward the outside onto the housing.
- Insert a feeler gauge in port (6). Measure the gap in ball and ramp mechanism (7). The minimum gap that is permissible is 3 mm (.12 inch). The maximum gap will indicate the wear limit for the brake discs. The maximum permissible gap that is allowed is 10 mm (.40 inch). If the maximum gap is reached, the brake discs and the ball and ramp mechanism will require replacement.
- Remove bolt (14). Ensure that you clean any dirt and oil from the threads of bolt (14) and adjusting nut (15) .
- You must adjust the stroke of the brake cylinder after you have completed this procedure.
Reference: Testing and Adjusting, "Brake Cylinder Stroke - Test and Adjust".