GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Driveline/Axle 🢒 Rear Drive Axle 🢒 Inter-Axle Differential Lock Control Valve Replacement

Removal Procedure

    Object Number: 199151 Size: MH
  1. Apply the parking brake.
  2. Block the wheels.
  3. Drain all of the air reservoirs. Refer to Air Brake Reservoir Draining .

    4. Important: Tag the air lines for later installation.

  4. Remove the air lines at the inter-axle differential lock control valve. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting .
  5. Remove the inter-axle differential lock control valve name plate screws (1).
  6. Remove the inter-axle differential lock control valve name plate (2).
  7. Remove the inter-axle differential lock control valve (3) from the instrument panel.
  8. Inspect the air lines for the following conditions:
    9. • Damage
    • Kinks
    • Wear
  9. Repair or replace the air lines as needed. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting .

Installation Procedure

    Object Number: 199151 Size: MH
  1. Install the inter-axle differential lock control valve (3) into the instrument panel.
  2. Install the inter-axle differential lock control valve name plate (2).

    3. Notice: Refer to Fastener Notice in the Preface section.

  3. Install the inter-axle differential lock control valve name plate screws (1).

    4. Tighten
    Tighten the screws (1) until fully seated. Do not strip the inter-axle differential lock control valve name plate screws (1).

  4. Install the air lines at the inter-axle differential lock control valve. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting .
  5. Start the engine. Charge the system to the air compressor governor cutout point.
  6. Stop the engine.
  7. Inspect for air leaks using a soap solution.
  8. Verify proper operation of the inter-axle differential lock.
  9. Remove the wheel blocks.