GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 797046  Size: SH
  1. Disconnect the electrical connector from the brake fluid level sensor.
  2. If you are performing repairs on a 3.4L, non ABS Impala, it is necessary to remove the bracket (1) from the master cylinder.
  3. Disconnect the brake pipes from the master cylinder.
  4. Important: Install a rubber cap or plug to the exposed brake pipe fitting ends in order to prevent brake fluid loss and contamination.

  5. Plug the open brake pipe ends.

  6. Object Number: 177372  Size: SH
  7. Remove master cylinder mounting nuts.
  8. Remove the master cylinder from the vehicle.
  9. Drain the master cylinder reservoir of all brake fluid.

Installation Procedure


    Object Number: 177372  Size: SH
  1. Bench bleed the master cylinder. Refer to Master Cylinder Bench Bleeding .
  2. Install the master cylinder to the vacuum brake booster.
  3. 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 master cylinder mounting nuts.
  5. Tighten
    Tighten the master cylinder mounting nuts to 25 N·m (18 lb ft).

  6. Remove the plugs from the brake pipes
  7. Connect the brake pipes to the master cylinder.
  8. Tighten
    Tighten the brake pipe fittings at the master cylinder to 15 N·m (11 lb ft).


    Object Number: 797046  Size: SH
  9. If you are performing repairs on a 3.4L, non ABS Impala, it is necessary to install the bracket (1) to the master cylinder.
  10. Connect the electrical connector to the brake fluid level sensor.
  11. Bleed the brake system. Refer to Hydraulic Brake System Bleeding .