GM Service Manual Online
For 1990-2009 cars only

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 assembly.


    Object Number: 221750  Size: SH
  1. Use the Scan Tool in order to perform the Gear Tension Relief Sequence.
  2. Disconnect the 2 electrical connectors (1) of the brake solenoid valve.
  3. Disconnect the electrical connector of the Brake Motor Pack.
  4. Place a shop towel beneath the hydraulic modulator brake pipes (2) in order to prevent brake fluid from contaminating the motor pack or the electrical connectors.
  5. Disconnect the brake pipes (2) from the hydraulic modulator (3). Note the positions of the brake pipes.
  6. Plug the brake pipes in order to prevent loss or in order to prevent contamination of the brake fluid.

  7. Object Number: 242622  Size: MH
  8. Remove the 3 nuts (5) and the hydraulic modulator/motor pack assembly from the vehicle.

Installation Procedure


    Object Number: 242622  Size: MH
  1. Install the Hydraulic modulator assembly 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 hydraulic modulator assembly to the bracket mounting nuts (5).
  4. Tighten
    Tighten the mounting nuts of the hydraulic modulator bracket to 5.4 N·m (48 lb in).


    Object Number: 221750  Size: SH
  5. Connect the brake pipes (2) to the hydraulic modulator (3).
  6. Tighten
    Tighten the tube nuts to 16 N·m (12 lb ft).

  7. Connect the electrical connector of the Brake Motor Pack.
  8. Connect the 2 electrical connectors (1) of the brake solenoid valve.
  9. Bleed the system. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes.
  10. Perform the A Diagnostic System Check - ABS .