GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 Montana 🢒 Engine 🢒 Engine Controls - 3.4L 🢒 Evaporative Emission Hoses/Pipes Replacement - Engine/Chassis

Removal Procedure

Caution: In order to reduce the risk of fire and personal injury observe the following items:

   • Replace all nylon fuel pipes that are nicked, scratched or damaged during installation, do not attempt to repair the sections of the nylon fuel pipes
   • Do not hammer directly on the fuel harness body clips when installing new fuel pipes. Damage to the nylon pipes may result in a fuel leak.
   • Always cover nylon vapor pipes with a wet towel before using a torch near them. Also, never expose the vehicle to temperatures higher than 115°C (239°F) for more than one hour, or more than 90°C (194°F) for any extended period.
   • Apply a few drops of clean engine oil to the male pipe ends before connecting fuel pipe fittings. This will ensure proper reconnection and prevent a possible fuel leak. (During normal operation, the O-rings located in the female connector will swell and may prevent proper reconnection if not lubricated.)

Caution: Do not breathe the air through the EVAP component tubes or hoses. The fuel vapors inside the EVAP components may cause personal injury.

Important: Always maintain cleanliness when servicing fuel system components.

  1. Remove the engine and transmission as an assembly. Refer to Engine Replacement in Engine Mechanical.

    2. Object Number: 724410 Size: SH
  2. Disconnect the evaporative emission (EVAP) purge pipe from the rear purge pipe (3).

    3. Object Number: 400659 Size: SH
  3. Perform the following procedures if equipped with auxiliary rear air and heat.
    4. 3.1. Disconnect the rear heater and A/C pipes from the rear heating, ventilation, and air conditioning (HVAC) module. Refer to Auxiliary HVAC Module Replacement in Heating, Ventilation and Air Conditioning.
    3.2. Move the rear heater and A/C pipes in order to remove the EVAP purge pipe.
  4. Note the position of the EVAP pipe and the EVAP pipe attaching hardware for installation.

    5. Object Number: 724387 Size: SH
  5. Disconnect the EVAP purge pipe from the engine compartment attaching clips (2).

    6. Object Number: 724389 Size: SH
  6. Disconnect the EVAP purge pipe from the chassis attaching clip (1).

    7. Object Number: 724391 Size: SH
  7. Remove the EVAP purge pipe.
  8. Inspect the pipe for bends, kinks, and cracks.
  9. Replace the pipe as required.

Installation Procedure

    Object Number: 724391 Size: SH
  1. Install the EVAP purge pipe.

    2. Object Number: 724389 Size: SH
  2. Connect the EVAP purge pipe to the chassis attaching clip (1).

    3. Object Number: 724387 Size: SH
  3. Connect the EVAP purge pipe to the engine compartment attaching clip (2).

    4. Object Number: 400659 Size: SH
  4. Perform the following procedures if equipped with auxiliary rear air and heat.
    5. 4.1. Move the rear heater and A/C pipes into their original position.
    4.2. Connect the rear heater and A/C pipes to the rear HVAC module. Refer to Auxiliary HVAC Module Replacement in Heating, Ventilation and Air Conditioning.

    Object Number: 724410 Size: SH
  5. Connect the fuel feed and return pipe or EVAP purge pipe from the fuel filter (2) and rear return pipe (4) or rear purge pipe (3).
  6. Install the engine and transmission as an assembly. Refer to Engine Replacement in Engine Mechanical.