GM 88971202 Power Brake Booster (Vacuum)

You can Select Your Vehicle to check if 88971202 fits your vehicle.

To perform an operating check on the power brake booster, start by depressing the brake pedal multiple times with the engine off and ensuring that there is no change in the pedal reserve distance. Then, depress the pedal and start the engine, checking if the pedal goes down slightly, indicating normal operation. For the air tightness check, start the engine and turn it off after one or two minutes. Slowly depress the brake pedal several times, noting if the pedal depresses less each time, indicating an airtight booster. Additionally, depress the brake pedal while the engine is running and stop the engine with the pedal depressed. If there is no change in the pedal reserve travel after holding the pedal for 30 seconds, the booster is airtight. When it comes to removal, power brake booster units should not be disassembled and should be replaced with a new or rebuilt one due to their complexity and critical relationship to brake performance. Begin by removing the brake master cylinder and the air filter housing. In the engine compartment, disconnect the vacuum hose from the booster. If the vehicle has cruise control, remove the cruise control actuator and bracket. Unclip or detach any brake lines around the booster as necessary to avoid damage. Locate the clevis connecting the booster pushrod to the brake pedal and remove the clevis pin retaining clip, then pull out the pin. Finally, remove the four nuts and washers holding the brake booster to the firewall and slide the booster straight out until the studs clear the holes. For installation, follow the reverse of the removal procedures, ensuring the clevis locknut and booster mounting nuts are tightened to the specified torque. If a new power brake booster unit is being installed, check the pushrod clearance to prevent brake dragging or excessive pedal travel. Adjust the pushrod length if necessary. After the final installation of the master cylinder, brake hoses, and lines, adjust the brake pedal height and free play and bleed the system.