GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2008 🢒 Astra 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Master Cylinder Replacement

Removal Procedure

    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.

  1. Remove the cover of the brake fluid reservoir.
  2. Siphon out as much brake fluid as possible with a siphon bottle.

    3. Object Number: 1941356 Size: SH
  3. Disconnect the wiring harness from the brake fluid reservoir.
  4. Disconnect the wiring harness plug (1) from the brake fluid level sensor.

    5. Object Number: 1941359 Size: SH

    Important: Collect the brake fluid and seal the apertures.

  5. Remove the brake fluid reservoir from the brake master cylinder.
    6. • Remove the bolt (1).
    • Remove the brake fluid reservoir carefully from the brake master cylinder.

    Object Number: 1941346 Size: SH

    Important: Collect the brake fluid and seal the apertures.

  6. For vehicles with manual transmission, remove the supply line (1) for clutch master cylinder from brake fluid reservoir.

    7. Object Number: 1941368 Size: LF
  7. Remove the brake line from the brake master cylinder.

    8. Remove the 2 union bolts (3).

    Important: Take out the brake master cylinder horizontally. The primary piston can drop out.

  8. Remove the brake master cylinder from the brake servo.

    9. Remove the 2 nuts (1, 2).

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.

    Important: Insert the brake master cylinder horizontally, the pressure piston may fall out. The pressure piston must not be extracted.

  1. Install the brake master cylinder to the brake servo.

    2. Tighten
    Tighten the 2 master cylinder to brake servo nuts to 21 N·m (16 lb ft).

  2. Install the brake line to the brake master cylinder.

    3. Tighten
    Tighten the 2 brake line to master cylinder retaining bolts to 14 N·m (124 lb in).

  3. For vehicles with manual transmission, install the supply line for the clutch master cylinder to the brake fluid reservoir.

    4. Important: Ensure the brake fluid reservoir is seated perfectly.

  4. Install the brake fluid reservoir to the brake master cylinder.

    5. Tighten
    Tighten the brake fluid reservoir to brake master cylinder bolt 6 N·m (53 lb in).

  5. Connect the wiring harness plug to the brake fluid level sensor.
  6. Connect the wiring harness on at the brake fluid reservoir.
  7. Bleed the brake system. Refer to Hydraulic Brake System Bleeding .
  8. Top up the brake fluid reservoir to the MAX marking. Refer to Master Cylinder Reservoir Filling .
  9. Install the cover on to the brake fluid reservoir.