924Gz Wheel Loader Braking System - Test Caterpillar

Service Brake Holding Ability Test

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Personal injury can result if the machine moves while testing. If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.

Check the area around the machine. Make sure that the machine is clear of personnel and clear of obstacles.

Make sure that the steering frame lock link is in the stored position.

Test the brakes on a dry, level surface.

Fasten the seat belt before you test the brakes.

The following tests are used to determine if the service brake is functional. These tests are not intended to measure the maximum brake holding effort. The brake holding effort that is required to sustain a machine at a specific engine rpm varies depending on the machine. The variations are the differences in the engine setting, in the power train efficiency, and in the brake holding ability.

1. Start the engine. Raise the bucket slightly.

2. Apply the service brake. Release the parking brake.

3. Press the top of the transmission neutralizer override switch.

4. Move the transmission control lever to THIRD SPEED FORWARD while the AUTO shift switch is in the OFF position.

5. Gradually increase the engine speed to high idle. The machine should not move.

6. Reduce the engine speed to low idle. Move the transmission to NEUTRAL. Engage the parking brake. Lower the blade to the ground. Stop the engine.

Refer to the Service Manual, KENR7607, "Service Brake Discs - Check" for the requirements of the disc thickness.

Secondary Brake Holding Ability Test

Check the area around the machine. Make sure that the machine is clear of personnel and clear of obstacles.

Make sure that the steering frame lock link is in the stored position.

Test the brakes on a dry, level surface.

Fasten the seat belt before you test the brakes.

The following tests are used to determine if the parking brake is functional. These tests are not intended to measure the maximum brake holding effort. The brake holding effort that is required to sustain a machine at a specific engine rpm varies depending on the machine. The variations are the differences in the engine setting, in the power train efficiency, and in the brake holding ability.

1. Start the engine. Raise the bucket slightly.

2. Engage the parking brake.

3. Move the transmission control lever to THIRD SPEED FORWARD, to NEUTRAL, and back to THIRD SPEED FORWARD. This operation will override the transmission neutralizer for this test.

Note: The parking brake indicator light should come on and the parking brake alarm should sound.

4. Gradually increase the engine speed to high idle. The machine should not move.

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If the machine begins to move, reduce the engine speed immediately and apply the service brake pedal.

5. Reduce the engine speed. Move the transmission to NEUTRAL. Lower the blade to the ground. Stop the engine.