GM 15854059 Power Brake Booster ASSEMBLY

To check the operating and airtightness of a vacuum booster, depress the pedal and start the engine. Ensure that the pedal goes down slightly and that there is no change in the pedal reserve distance. For a hydraulic booster, turn off the engine and depress the brake pedal to deplete the pressure in the accumulator. If the booster is working properly, the brake pedal will sink toward the floor and then rise back up against your foot. To remove the booster, disconnect the cable from the negative battery terminal, detach the vacuum or pressure and return lines, remove the master cylinder, disconnect any electrical connectors, and remove the pushrod retaining clip and the four nuts retaining the booster. To install the booster, use a new gasket and tighten the mounting nuts to the torque specifications. If working with a hydraulic booster, bleed the power steering system and check the fluid level.

Depress the pedal and start the engine, ensuring that the pedal goes down slightly and that there is no change in the pedal reserve distance.