GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Park Avenue 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Power Vacuum Brake Booster Replacement

Removal Procedure

    Important: The booster can be removed from the vehicle without removing or disconnecting the master cylinder. However, if both the booster and the master cylinder are to be removed, remove the master cylinder first. Refer to Master Cylinder Replacement .

  1. Remove the booster vacuum hose from the vacuum check valve.

    2. Object Number: 177410 Size: SH
  2. Remove the master cylinder attaching nuts (3).
  3. Disconnect the master cylinder from the booster. Move the master cylinder forward just enough to clear the studs on the booster. This will flex the brake pipes slightly. Do not bend or distort the pipes (4).
  4. Remove the acoustical barrier from the booster studs (under I/P).
  5. Remove the booster attaching nuts.
  6. Remove the booster pushrod from the brake pedal. Tilt the entire booster slightly the pushrod off of the pedal clevis pin without putting undue side pressure on the pushrod.

    7. Object Number: 177411 Size: SH
  7. Remove the booster (2) from the vehicle.

    8. Object Number: 177414 Size: SH
  8. Remove the gasket.

Installation Procedure

    Object Number: 177414 Size: SH
  1. Connect the gasket to the booster.

    2. Object Number: 177411 Size: SH
  2. Install the booster to the vehicle.
  3. Install the booster pushrod to the brake pedal. Tilt the entire booster slightly to work the pushrod onto the pedal clevis pin without putting undue side pressure on the pushrod.

    4. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  4. Install the booster attaching nuts

    5. Tighten
    Tighten the attaching nuts to 21 N·m (15 lb ft).

  5. Install the acoustical barrier onto the booster studs (under I/P)/

    6. Object Number: 177410 Size: SH
  6. Install the master cylinder to the booster.
  7. Install the master cylinder attaching nuts.

    8. Tighten
    Tighten the attaching nuts to 27 N·m (20 lb ft).

  8. Install the booster vacuum hose to the vacuum check valve.