GM 84635614
Brake Booster

Park your vehicle on a flat surface and activate the parking brake before you start replacing the power vacuum Brake Booster. Press the brake pedal several times with the engine off until the brake feeling returns to normal to empty the brake vacuum storage. First take off the air cleaner system and next disconnect the windshield washer solvent heater. Unplug the master cylinder fluid level sensor connector and take out the vacuum Brake Booster check valve and hose assembly. Also free the vacuum Brake Booster vacuum sensor and store it safely. Unhook the front and rear brake pipes from the frame rail holder and take off 2 nuts from the bpmv assembly without breaking the brake lines. Place the bpmv assembly above vehicle studs while moving it forward at the beginning of its route. Separate the 2 Brake Master Cylinder nuts while leaving brake pipes connected, then take out the master cylinder unit that stays upright with strong mechanics wire support. Take out the driver knee bolster and instrument panel insulator from the left side in order to access the needed areas. Unbolt and separate the brake pedal pushrod locking clip and clevis pin for brake pedal pushrod removal. Take out both pieces of the Steering Shaft and remove the four vacuum Brake Booster nuts. Moving the vacuum Brake Booster ahead and pivoting it upwards lets you remove it from the dash panel mounting studs. Before reusing the vacuum Brake Booster assess its gasket's condition then replace it when damage is found. Secure the vacuum Brake Booster mounting studs against the dash panel and fasten them with 4 adjusted nuts at 25 nm torque. Place the intermediate Steering Shaft back and connect the pushrod from the brake pedal to its location before installing the clevis pin with a retaining clip. Reinstall the driver knee bolster followed by the left side instrument panel insulator panel. Make sure the master cylinder seal matches specifications before fitting it to the vacuum booster and tightening the 2 Brake Master Cylinder nuts to 20 nm but no more. Put the bpmv component above the studs then bolt with two nuts at 20 nm force. Connect the master cylinder fluid level sensor electrical connector to the brake pipes and attach them to the frame rail routing clip. Connect both vacuum Brake Booster components (vacuum sensor and check valve) through their separate installation ports. Complete the job by putting back the windshield washer solvent heater and air cleaner parts.