GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Brakes 🢒 Air Brakes 🢒 Rear Air Brake Relay Double Check Valve Replacement

Removal Procedure
  1. Block the wheels.
  2. Drain all of the air reservoirs. Refer to Air Brake Reservoir Draining .
  3. Tag or label the lines for installation.
  4. Remove the air lines from the relay double check valve. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting .

    5. Object Number: 227936 Size: SH
  5. Remove the relay double check valve.
  6. Inspect the air lines for the following conditions:
    7. • Damage
    • Kinks
    • Wear
  7. Replace any damaged, kinked, or worn air lines.

Installation Procedure
  1. Install the relay double check valve.

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


    Object Number: 227936 Size: SH
  2. Install the following components:
    3. • The bolts

    Tighten
    Tighten the relay valve bolts to 52 N·m (38 lb ft).

    • The washers
    • The nuts
  3. Install the air lines to the relay double check valve. Refer to Hose and Line Replacement - Nylon Push-In Type Fitting .
  4. Perform the air leakage test. Refer to Rear Relay Double Check Valve Operational Check .
  5. Perform the operational test. Refer to Rear Relay Double Check Valve Leakage Test .
  6. Remove the wheel blocks.