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: 221629  Size: SH
  1. Use the Scan Tool in order to perform the Gear Tension Relief Sequence.
  2. Disconnect the Motor Pack, the ABS solenoid, and the shuttle switch electrical connectors.
  3. Place a shop towel beneath the hydraulic modulator brake pipes to prevent brake fluid from contaminating the motor pack or the electrical connectors.
  4. Disconnect the brake pipes from the hydraulic modulator and the shuttle valve. Note the position of the brake pipes.
  5. Plug the brake pipes to prevent loss or contamination to the brake fluid.
  6. Remove the three retaining bolts (2) and remove the brake modulator/motor pack assembly from the vehicle.

Installation Procedure


    Object Number: 221629  Size: SH

    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.

  1. Install the brake modulator/motor pack assembly to the vehicle and then install the three retaining bolts (2).
  2. Tighten
    Tighten the Hydraulic modulator/motor pack assembly retaining bolts to 5.4 N·m (48 lb in).

    Remove the plugs from the brake pipes and connect the pipes to the brake modulator; secure each brake pipe with one pipe nut.

    Tighten
    Tighten the pipe nuts to 15 N·m (11 lb ft).

  3. Connect the motor pack, ABS solenoids, and the shuttle valve switch electrical connectors.
  4. Important: Bleed the system. Refer to Bleeding Brake Hydraulic System in Brakes.

  5. Perform the Diagnostic System Check .