GM 94857034
Brake Booster

Start your Vacuum Brake Booster replacement process by collecting the Booster Push Rod Gauge (J39567). Start by taking off the master cylinder and pull out all parts related to ABS including the brake pressure modulator valve assembly and its bracket. Unfasten the hose clamp and hose connection from the booster while also removing the brake pedal return spring. Disconnected parts include the push rod clevis wave washer clevis pin and cotter pin . Remove the booster assembly by removing four fasteners: nuts 7, 8, 12 and 13. Secure the booster assembly with nuts 7, 8, 12, and 13 tightened to 13 Nm while placing a new gasket between it and the bulkhead. Connect the clevis end of the operating rod to the booster that has the gasket. Assemble the brake pedal return spring onto the clevis after adding both pins and the wave washer. When your vehicle has ABS, install the gasket then add the brake pressure modulator valve assembly bracket and its three nuts without tightening them. Rest the new gasket on the master cylinder while placing the Booster Push Rod Gauge (J39567) on top of it. Lower the pin until it touches the master cylinder piston and remove the gauge before setting it upside down. Place the gauge on the brake pressure modulator bracket assembly when the car has ABS but attach it to the booster assembly when there is no ABS. Put the booster piston rod against the gauge to check its zero clearance value. An assistant should push out the booster piston rod through the brake pedal until it contacts the head when the dimensions vary. After installing the brake pressure modulator valve assembly put on the master cylinder assembly then fasten all three nuts to 13 Nm torque specification. Install the hose onto the booster assembly and fasten it with a hose clamp. Complete the brake work by bleeding the brakes while looking for leaks then setting the brake pedal height before fastening the clevis lock nut to 19 ft. lbs (26 Nm).

Install the wave washer, clevis pin, and cotter pin to the clevis, followed by the brake pedal return spring.

Ensure it is 0 mm (0 inch).