GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC C-Series Medium Duty Truck B7 🢒 Brakes 🢒 Air Brakes 🢒 Low Air Pressure Switch Replacement

Removal Procedure
  1. Apply the parking brake.
  2. Block the wheels.
  3. Drain all the reservoirs. Refer to Draining Reservoirs .
  4. Remove the low air pressure switch wiring harness connector.

    5. Object Number: 201634 Size: MH
  5. Remove the low air pressure switch.

Installation Procedure

    Object Number: 201634 Size: MH

    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 low air pressure switch wiring harness connector.

    2. Tighten
    Tighten the low air pressure switch to 12 N·m (106 lb in).

  2. Start the engine.
  3. Charge the system air pressure to the governor cut-out point.
  4. Check for leaks with a soap solution around the low air pressure switch.

    5. Leakage is not permissible.

  5. Check for the proper operation.
  6. Remove the wheel blocks.