GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Body Systems 🢒 Horns 🢒 Air Horn Replacement

Removal Procedure
  1. Discharge the air pressure from the air brake system. Refer to Air Brake Reservoir Draining.

    2. Object Number: 206653 Size: SH
  2. Remove the lanyard bolt from the inner roof panel.

    3. Object Number: 206665 Size: SH
  3. Remove the left rear quarter trim panel (models with headliner). Refer to Headlining Trim Panel Replacement.
  4. Remove the air horn opening trim cover, if used.
  5. Remove the air horn air tube from the air horn valve.
  6. Tape the air horn air tube to the roof in order to help prevent the air line from recoiling back into the roof panel.

    7. Object Number: 881164 Size: SH
  7. Remove the air horn front mounting bracket.
  8. Remove the air horn mounting bolts.
  9. Remove the air horn assembly from the roof.
  10. Remove the tape from the air horn tube roof.

Installation Procedure
  1. Connect the air horn tube to the air horns.
  2. Route the lanyard through the roof into the cab.
  3. Install the air horn assembly to the roof.

    4. Object Number: 881164 Size: SH
  4. Install the air horn front mounting bracket.

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

  5. Install the air horn mounting bolts.

    6. Tighten
    Tighten the air horn mounting bolt to 9 N·m (80 lb in).


    Object Number: 206665 Size: SH
  6. For models with headliner, install the left rear quarter trim panel. Refer to Headlining Trim Panel Replacement.

    7. Object Number: 206653 Size: SH
  7. Install the lanyard bolt to the inner roof panel.

    8. Tighten
    Tighten the lanyard bolt to 2 N·m (18 lb in).