Hydraulic Brake Assist Noise Inspection
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2003 GMC Savana Special, 2003 GMC Savana Camper Special, 2003 GMC Savana, 2003 Chevrolet RV Cutaway, and 2003 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
DO NOT apply 100 lbs. (445 N) of force or more to the brake system pedal for more than 5 seconds at a time.
NOTE:
Required Tools: Brake Pedal Effort Gage (J-28662).
- Install the Brake Pedal Effort Gage to the brake pedal. Start the engine and allow it to idle. Ensure that the wheels are directed straight ahead. Apply and maintain the brakes with 25 lbs (111 N) of force to the brake pedal, as indicated on the Brake Pedal Effort Gage. Observe for noises.
- Quickly release the brakes. Observe for noises. If chatter and/or a vibration of the brake pedal was apparent during the brake system apply of 25 lbs (111 N) of force, the power steering drive belt is probably slipping and would require replacement.
- If any significant noise was apparent during the quick release of the brakes following the brake system apply of 25 lbs (111 N) of force, there is likely a restriction in the hydraulic brake booster power steering return hose and it would require replacement.
- Apply the brakes with 40 lbs (178 N) of force to the brake pedal, as indicated on the Brake Pedal Effort Gage, then gradually increase pedal effort up to 100 lbs (445 N) of force for not more than 5 seconds at a time. Observe for noises. Quickly release the brakes. Observe for noises.
- If a hiss noise was apparent and increased during the brake system increasing apply of 40-100 lbs (178-445 N) of force, the hydraulic brake booster assist system is operating normally from an audible standpoint.
- If a clunk, chatter, and/or clicking noise was apparent during the quick release of the brakes following the brake system increasing apply of 40-100 lbs (178-445 N) of force, the hydraulic brake booster assist system is operating normally from an audible standpoint.