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Personal injury can result if the machine moves while testing the parking brake. If the machine begins to move during the test, reduce the engine speed immediately and apply the service brakes. |
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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, "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. |
Note: This test will determine whether the parking brake is functional. The test is not intended to measure the maximum brake holding effort. The brake holding effort that is required to prevent machine movement at a specific engine rpm varies depending on the machine. The variations include the engine setting, power train efficiency, the brake holding ability, etc.
Test the brakes on a hard, dry, level surface that is free of debris. Keep all personnel away from the area around the machine. Make sure that the steering frame lock is in the STORED position.
- Start the engine and raise the implement slightly. Allow the oil pressure in the accumulators to reach the cutout pressure.
- Move the Steering Transmission Integrated Control (STIC) and transmission control to the UNLOCKED position.
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Illustration 1 g02701896 Parking brake knob - Make sure that the parking brake control knob is pulled out all the way. Move the STIC upshift switch to THIRD SPEED FORWARD. Move the STIC transmission direction control switch to the FORWARD (F) position.
- Gradually increase the engine speed to high idle. The machine should not move.
- Reduce the engine speed to low idle. Move the STIC transmission direction control switch to the NEUTRAL position.
- Lower the implement to the ground and stop the engine.
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Illustration 2 g06222006 Parking brake
(1) Spring
(2) Plate
(3) Disc
(4) Bolt
(5) Bolt
(6) Hub
(7) Shaft
(8) Chamber
(9) Plate
(10) Pin
(11) Bearing cage
(12) Piston
(13) Plate - Check the wear on the brake discs and on the reaction plates. The minimum thickness of seven discs (3) and of six plates (13) is
70.0 mm (2.76 inch) . Check the force of springs (1).
If the machine moved during the test, consult your Caterpillar dealer for a brake inspection. Make any necessary repairs before the machine is returned to operation.