GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Important: Clean all evaporative emission (EVAP) pipe connections and surrounding areas before disconnecting the pipes in order to avoid possible EVAP system contamination.


    Object Number: 855747  Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. If vehicle is a 1500 series, perform the following steps.
  3. Disconnect the evaporative emission (EVAP) canister vent pipe (5) from the canister.
  4. Remove the EVAP canister vent pipe clip (4) from the canister bracket.
  5. Remove the chassis harness from the EVAP canister vent pipe clip.
  6. Disconnect the EVAP canister vent pipe at the EVAP vent valve.
  7. Remove the EVAP canister vent pipe from the mounting clips (6, 7).
  8. Remove the EVAP canister vent pipe clip (3) from the frame.
  9. Cap the EVAP vent valve and canister in order to prevent possible EVAP system contamination.
  10. Remove the EVAP canister vent pipe.

  11. Object Number: 856670  Size: SH
  12. If vehicle is a 2500 series, perform the following steps.
  13. Disconnect the EVAP canister vent pipe (3) from the canister.
  14. Remove the EVAP canister vent pipe clip from the canister bracket.
  15. Remove the chassis harness from the EVAP canister vent pipe clip.
  16. Disconnect the EVAP canister vent pipe at the EVAP vent valve.
  17. Remove the EVAP canister vent pipe from the mounting clip.
  18. Remove the EVAP canister vent pipe clip (2) from the frame.
  19. Cap the EVAP vent valve and canister in order to prevent possible EVAP system contamination.
  20. Remove the EVAP canister vent pipe.

Installation Procedure


    Object Number: 856670  Size: SH
  1. If vehicle is a 2500 series, perform the following steps.
  2. Install the EVAP canister vent pipe.
  3. Remove the caps from the EVAP vent valve and canister.
  4. Install the EVAP canister vent pipe clip (2) to the frame.
  5. Install the EVAP canister vent pipe to the mounting clip.
  6. Connect the EVAP canister vent pipe at the EVAP vent valve.
  7. Install the chassis harness to the EVAP canister vent pipe clip.
  8. Install the EVAP canister vent pipe clip to the canister bracket.
  9. Connect the EVAP canister vent pipe (3) to the canister.

  10. Object Number: 855747  Size: SH
  11. If vehicle is a 1500 series, perform the following steps.
  12. Install the EVAP canister vent pipe.
  13. Remove the caps from the EVAP vent valve and canister.
  14. Install the EVAP canister vent pipe clip (3) to the frame.
  15. Install the EVAP canister vent pipe to the mounting clip.
  16. Connect the EVAP canister vent pipe at the EVAP vent valve.
  17. Install the chassis harness to the EVAP canister vent pipe clips (6, 7).
  18. Install the EVAP canister vent pipe clip (4) to the canister bracket.
  19. Connect the EVAP canister vent pipe (5) to the canister.
  20. Lower the vehicle.