Hydraulic Brake Assist System Noise Inspection

Tools Required 

J 28662  Brake Pedal Effort Gage

1. Install the J 28662 to the brake pedal.
2. Start the engine and allow it to idle. Ensure that the wheels are directed straight ahead.
3. Apply and maintain the brakes with 111 N (25 lb) of force to the brake pedal, as indicated on the J 28662. Observe for noises.
4. Quickly release the brakes. Observe for noises.
5. If chatter and/or a vibration of the brake pedal was apparent during the brake system apply of 111 N (25 lb) of force, the power steering drive belt is probably slipping and would require replacement.
6. If any significant noise was apparent during the quick release of the brakes following the brake system apply of 111 N (25 lb) of force, there is likely a restriction in the hydraulic brake booster power steering return hose and it would require replacement.

   Important:  Do NOT apply 445 N (100 lb) of force or more to the brake system pedal for more than 5 seconds at a time.

7. Apply the brakes with 178 N (40 lb) of force to the brake pedal, as indicated on the J 28662, then gradually increase pedal effort up to 445 N (100 lb) of force for not more than 5 seconds at a time. Observe for noises.
8. Quickly release the brakes. Observe for noises.
9. If a hiss noise was apparent and increased during the brake system increasing apply of 178-445 N (40-100 lb) of force, the hydraulic brake booster assist system is operating normally from an audible standpoint.
10. If a clunk, chatter, and/or clicking noise was apparent during the quick release of the brakes following the brake system increasing apply of 178-445 N (40-100 lb) of force, the hydraulic brake booster assist system is operating normally from an audible standpoint.