Power Brake Booster Piston Rod Adjustment

1. Remove brake booster. See POWER BRAKE BOOSTER  under REMOVAL & INSTALLATION.
2. Push the piston rod several times, ensuring that the reaction disc is in place. See Fig 1 . Maintain atmospheric pressure inside the booster when measuring the clearance.
3. Place the Brake Booster Piston Rod Height Gage (J-39567) on the master cylinder. See Fig 2 . Push the Brake Booster Piston Rod Height Gage pin down until it touches the master cylinder piston. Remove the Brake Booster Piston Rod Height Gage from the master cylinder.
4. Turn the Brake Booster Piston Rod Height Gage upside down and set it on the booster assembly. There should be no clearance between booster piston rod and Brake Booster Piston Rod Height Gage.
5. If there is clearance between booster piston rod and Brake Booster Piston Rod Height Gage, use the Brake Booster Piston Rod Adjuster (J-37767) in order to hold the booster piston rod. See Fig 3 . Turn the adjusting screw of the piston rod in order to adjust the clearance.

Fig 1: Adjusting Brake Booster Push Rod (1 Of 3)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Adjusting Brake Booster Push Rod (2 Of 3)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Adjusting Brake Booster Push Rod (3 Of 3)

Courtesy of GENERAL MOTORS CORP.