GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Block the vehicle wheels.
  2. Tilt the cab. Refer to Cab Tilting in General Information.
  3. Position a suitable container in order to catch the fluid from the flow switch and the hose. Do not re-use the old fluid.
  4. Remove the electrical connector from the flow switch.
  5. Notice: Do not tighten the flow switch with a thick blade wrench. The flow switch may be damaged. Use a thin blade open end wrench.

  6. Use an open wrench in order to remove the flow switch.
  7. Remove the O-ring seal.

Installation Procedure

  1. Install the new O-ring seal.
  2. Notice: Do not tighten the flow switch with a thick blade wrench. The flow switch may be damaged. Use a thin blade open end wrench.

    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. Use an open end wrench in order to install the flow switch.
  4. Tighten
    Tighten the flow switch to 10 N·m (88 lb in).

  5. Connect the electrical connector to the flow switch.
  6. Fill the hydraulic pump reservoir.
  7. Bleed the system.
  8. Inspect the vehicle for proper brake operation.
  9. Remove the wheel blocks.
  10. Lower the cab. Refer to Cab Tilting in General Information.