Tools Required
J 28662 
 Brake Pedal Effort Gage
- Install the 
J 28662 
 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 111 N·m (25 lb) of force to the brake pedal, as indicated on the 
J 28662 
 . Observe for noises.
 
- Quickly release the brakes. Observe for noises.
 
- Check the pump and motor are running. If the noise is excessive/abnormal, check the following:
 
| •  | Damaged high pressure pipe | 
 
| •  | Defective pump and motor mounts | 
 
| •  | Defective pump and motor assembly | 
 
Important: Do NOT apply 445 N·m (100 lb) of force or more to the brake system pedal for more than 5 seconds at a time.
- Apply the brakes with 178 N·m (40 lb) of force to the brake pedal, as indicated on the 
J 28662 
 , then gradually increase pedal effort up to 445 N·m (100 lb) 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 178-445 N·m (40-100 lb) 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 178-445 N·m (40-100 lb) of force, the hydraulic brake booster
assist system is operating normally from an audible standpoint.