GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2007 🢒 G6 🢒 Preface 🢒 Cautions and Notices 🢒 Master Cylinder Replacement

Caution: Refer to Brake Fluid Irritant Caution in the Preface section.

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in the Preface section.

Removal Procedure

    Object Number: 1222406 Size: SH
  1. Deplete the vacuum from the vacuum brake booster by removing the vacuum check valve (1) from the vacuum brake booster grommet (4). Do not disconnect the vacuum check valve (1) from the vacuum brake hose (3).
  2. Disconnect the electrical connector from the brake fluid level sensor.

    3. Object Number: 1219526 Size: SH
  3. Disconnect the brake pipes from the master cylinder.

    4. Object Number: 1219209 Size: SH

    Important: Install a rubber cap or plug to the exposed brake pipe fitting end in order to prevent brake fluid loss and contamination.

  4. Plug the open brake pipe fitting ends.
  5. Remove the 2 master cylinder mounting nuts.
  6. Remove the master cylinder, ensure the master cylinder-to-vacuum brake booster seal for damage. Replace seal if necessary.
  7. Remove the reservoir from the master cylinder if it is to be reused on a replacement master cylinder. Refer to Master Cylinder Reservoir Replacement .

Installation Procedure
  1. Install the brake master cylinder reservoir to the master cylinder if it was removed previously. Refer to Master Cylinder Reservoir Replacement .
  2. Bench bleed the master cylinder. Refer to Master Cylinder Bench Bleeding .
  3. Check to ensure that the master cylinder-to-vacuum brake booster seal is properly seated on the master cylinder barrel.

    4. Object Number: 1219209 Size: SH
  4. Install the master cylinder to the vacuum brake booster.

    5. Notice: Refer to Fastener Notice in the Preface section.

  5. Install the 2 brake master cylinder mounting nuts.

    6. Tighten
    Tighten the 2 brake master cylinder mounting nuts to 25 N·m (18 lb ft).

  6. Remove the plugs from the brake pipes.

    7. Object Number: 1219526 Size: SH
  7. Install the brake pipes to the master cylinder.

    8. Tighten
    Tighten the brake pipe fittings at the master cylinder to 20 N·m (15 lb ft).

  8. Connect the electrical connector to the brake fluid level sensor.

    9. Object Number: 1222406 Size: SH
  9. Connect the vacuum brake booster check valve (1) to the vacuum brake booster grommet (4).
  10. Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding .