904B Wheel Loader Power Train Caterpillar

Show/hide table

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.

Parking Brake Test

The following test is used to determine if the parking brake is functional. These tests are not intended to measure the maximum brake holding effort. Before any tests are performed, visually inspect the complete braking system for oil leaks and damaged parts. Refer to Testing and Adjusting, "Visual Inspection". Before any tests are performed, prepare the machine for troubleshooting. Refer to Testing and Adjusting, "Machine Preparation for Troubleshooting".

Test the brakes on a dry 20% slope.

1. Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel. Make sure that the steering frame lock link is in the STORED position.

2. Lower the work tool to the ground. Stop the engine.

3. Engage the parking brake.

4. Fasten the seat belt. Start the engine. Raise the work tool slightly.

5. Apply the service brake.

6. Release the service brake gradually.

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

   The machine should not move under the following conditions.

   • The engine is at low idle.

   • The bucket is empty.

   • The machine is warmed up and the machine is fully stopped.

   • The parking brake is pulled up firmly.

Show/hide table

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

7. After testing, lower the work tool to the ground and stop the engine.

Show/hide table

NOTICE
Driving through the brake for more than 15 seconds may damage the brake.

8. If the machine moved, inspect the parking brake components for wear or damage. Replace the bad parking brake components before returning the machine to service.

   Note: If the machine moves, adjust the parking brake control. Refer to "Adjustment Procedure For The Parking Brake Control". If the machine does not pass the parking brake test after the adjustment, refer to Testing and Adjusting, "Braking System Troubleshooting" for other probable causes.

Adjustment Procedure For The Parking Brake Control

Show/hide table

Personal injury or death can result from a parking brake malfunction. Do not operate the machine if the parking brake does not function correctly. Be sure the parking brake components are adjusted correctly before attempting to return the machine to service.

Illustration 1	g01157003
(1) Parking Brake Lever (2) Parking Brake Cable (3) Transfer Gear Group

1. Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel.

2. Lower the work tool to the ground. Stop the engine.

3. Engage the parking brake. Connect the steering frame lock.

4. Place chocks in front of the wheels and behind the wheels.

5. Place the parking brake in the DISENGAGED position.

Show/hide table



Illustration 2	g01157138

6. Check the end of the cable (2). The end of the cable should be hooked into the lever (1) .

7. Check the connector (4). The end of cable (2) should be hooked into the connector (4). Also, the connector (4) should be hooked to the lever (1) with the pin (5) .

Show/hide table



Illustration 3	g01157327
(1) Parking Brake Lever (A) Cable Travel (29.9 mm (1.18 inch)) (B) Full engagement for the Parking Brake Lever is at 39.4°. (C) Full disengagement of the Parking Brake Lever is at minus 13.4°. (E) Level position at 0°

8. Pull Brake lever (1) so the lever (1) is in position (E) .

Show/hide table



Illustration 4	g01157263

9. Check the connector (6). The end of cable (2) should be hooked into the connector (6). Also, the connector (6) should be hooked to the lever on the transfer gear group (3) with the pin (7) .

Show/hide table



Illustration 5	g01157387

10. Check the connector (8) for the service brake cable on the transfer gear group (3). The connector (8) should be against the pin (9). If adjustment is necessary, refer to Power Train, RENR9757, "Power Train Systems Operation Testing and Adjusting", "Service Brake - Test and Adjust".

Show/hide table



Illustration 6	g01157263

11. Remove the pin (7) in order to disconnect the connector (6) from the lever on the transfer gear group (3) .

Show/hide table



Illustration 7	g01157453

12. Loosen the locknut (10). Turn the connector (6) in order to adjust the cable (2). Adjust the cable so that the connector (6) is against the pin (7). Then, turn the connector (6) clockwise for one full revolution.

    Note: Turn the connector (6) clockwise in order to tighten the cable (2). Turn the connector (6) counterclockwise in order to loosen the cable (2) .

13. Reinstall the cable (2) to the lever on the transfer gear group (3) with the pin (7) .

14. Test the parking brake. Refer to Testing and Adjusting, "Parking Brake - Test" for the procedure.

Adjustment Procedure For The Parking Brake Switch

Illustration 8	g01157610

The parking brake indicator (G) on the operator panel and the NEUTRAL indicator (H) on the operator panel will light when the parking brake lever is pulled up.

Brake Indicator Light (F) - This indicator light indicates that the parking brake is engaged.

Parking Brake (G) - The alert indicator will light when the parking brake is engaged. The alert indicator should come on during start-up. The alert indicator should go out when the parking brake is released.

NEUTRAL (H) - The indicator will light when the direction control switch is in the NEUTRAL position.

1. Move the machine to a smooth, horizontal location. Move the machine away from other operating machines and away from personnel.

2. Lower the work tool to the ground. Stop the engine.

3. Engage the parking brake. Connect the steering frame lock.

4. Place chocks in front of the wheels and behind the wheels.

Show/hide table



Illustration 9	g01157662

5. Remove the cover assembly (11) .

6. Disengage the parking brake.

7. Engage the parking brake lever (1) for two clicks.

8. Turn the engine start switch to the ON position. This will activate all the cab circuits.

Show/hide table



Illustration 10	g01157695

9. Loosen the two nuts (12) .

10. Push down on the switch (13) until the alert indicator (G) turns off. Push up on the switch (13) until the alert indicator (G) just comes on.

Show/hide table



Illustration 11	g01157695

11. Tighten the two nuts (12) .

12. Engage the parking brake.

13. Turn the engine start switch to the OFF position.

Show/hide table



Illustration 12	g01157662

14. Install the cover assembly (11).

15. Remove the chocks.

16. Disconnect the steering frame lock.