GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Express 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Combination Valve Replacement

Removal Procedure

Important: Note the identification code on the valve. Have the proper code when ordering a replacement valve.

  1. Raise the vehicle and properly support it with safety stands.

    2. Object Number: 182658 Size: SH
  2. Remove the retaining bolts from the shield.
  3. Remove the shield.

    4. Object Number: 182662 Size: SH
  4. Disconnect the 2-way electrical connector from the combination valve.

    5. Object Number: 161517 Size: SH
  5. Disconnect the front and rear brake pipes from the combination valve.

    6. Object Number: 161581 Size: SH
  6. Remove the Allen bolts that fasten the combination valve to the BPMV.
  7. Remove the combination valve from the BPMV.
  8. Install the transfer tubes to the valve.

Installation Procedure

Important: 

   • Do not reuse the old transfer tubes. Always install new transfer tubes with a new combination valve.
   • Ensure that the replacement combination valve has the same pin punched identification code as the old part.

  1. Install the transfer tubes into the combination valve until the transfer tubes are fully seated.

    2. Object Number: 161581 Size: SH
  2. Install the combination valve to the BPMV.

    3. 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 Allen bolts to the combination valve and the BPMV.

    4. Tighten

        • Tighten the Allen bolts of the combination valve to 8 N·m (6 lb ft).
        • Tighten the Allen bolts of the combination valve a second time to 16 N·m (12 lb ft).

    Object Number: 161517 Size: SH
  4. Connect the front and rear brake pipes to the combination valve.

    5. Tighten
    Tighten the brake pipe fittings to the combination valve to 30 N·m (22 lb ft).


    Object Number: 182662 Size: SH
  5. Connect the 2-way electrical connector to the combination valve.

    6. Object Number: 182658 Size: SH
  6. Install the shield to the vehicle.
  7. Install the retaining bolts of the shield.

    8. Tighten
    Tighten the retaining bolts of the shield to 12 N·m (8 lb ft).

    Important: Make sure that the metering rod of the combination valve is depressed during bleeding.

  8. Bleed the brake hydraulic system. Refer to Hydraulic Brake System Bleeding .