GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Caution: To help avoid personal injury, due to a retained load on the brake modulator, the Gear Tension Relief function of the scan tool must be performed prior to removal of the ABS brake modulator/master cylinder assembly.


    Object Number: 183883  Size: SH
  1. Use the scan tool in order to perform the Gear Tension Relief Sequence.
  2. Disconnect the 2 brake solenoid valve electrical connectors (1,3).
  3. Disconnect the brake fluid level indicator sensor connector (2).
  4. Disconnect the ABS brake motor pack 6-way electrical connector (6).
  5. Remove the 4 brake pipes (5).
  6. Remove the 2 nuts (8) attaching the ABS brake modulator/master cylinder assembly (7) to the vacuum booster.
  7. Remove the ABS brake modulator/master cylinder assembly (7).

Installation Procedure


    Object Number: 183883  Size: SH
  1. Install the ABS brake modulator/master cylinder assembly (7) into the vehicle.
  2. 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.

  3. Install the 2 nuts (8) in order to attach the ABS modulator/master cylinder assembly (7).
  4. Tighten
    Tighten the ABS brake modulator/master cylinder nuts (8) to 27 N·m (20 lb ft).

  5. Install the 4 brake pipes (5) onto the ABS brake modulator/master cylinder assembly (7).
  6. Tighten
    Tighten the tube nuts to 24 N·m (18 lb ft).

  7. Connect the ABS brake motor pack 6-way electrical connector (6).
  8. Connect the brake fluid level indicator sensor electrical connector (2).
  9. Connect the 2 brake solenoid valve electrical connectors (1,3).
  10. Bleed the system. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes.