Wet Carpet/Odor in Passenger Foot Well Area (Repair Evaporator Case Drain to Cowl Seal/Open Evaporator Case Drain)

This bulletin is being revised to add the drain tube installation to the service procedure. Please discard Corporate Bulletin Number 01-01-38-009 (Section 01-HVAC).

Some owners may comment that the carpet in the passenger foot well of the vehicle is wet and the interior of the vehicle has an odor.

This condition may be caused by a plugged evaporator case drain or a leaking evaporator case drain to cowl seal leak.

Make a simple tool to clean the evaporator case drain following these steps:

1. Obtain a fixed antenna mast (new or used).
2. Measure from the tip of the antenna a distance of 121 mm (4.75 in) and make a paint line or tape line completely around the antenna mast. This will be the depth stop reference.

This antenna tool is to be reused.

2001 Aztek and 2002 Rendezvous Vehicles Only:

1. Place the vehicle in the service stall over a hoist.
2. Open the hood.
3. With a light (a flashlight works best), look over the top of the engine between the back of the generator and the power brake vacuum hose attachment to the intake plenum. Look down to the base of the cowl to locate the evaporator case drain outlet.
4. Insert the antenna mast tool described above into the evaporator case drain to the depth stop reference line on the antenna mast. Some force may be required the last 6.35 mm (.25 in) as you break away the flashing on the inside of the HVAC case covering the drain tube.

For All Vehicles Covered in this Bulletin:

1. Raise the vehicle.
2. From underneath the vehicle, locate the HVAC case drain tube. Determine the best access route to the evaporator drain, as you will need to place a bead of sealer around the outside of the HVAC case drain tube and install the new rubber drain tube elbow and bridge the area to the sheet metal of the cowl.
3. Place a thin film of silicone on the inside of the new rubber elbow.
4. Place the rubber elbow over the HVAC drain tube with the outlet pointing down.
5. With gloves protecting your hand, place a line of RTV sealer onto the area between the rubber elbow and the sheet metal of the cowl and spread it out smoothly with your finger.
6. Lower the vehicle and inspect the sealed area from the top down. Be sure not to plug the HVAC outlet drain tube with the sealer.
7. Verify the proper operation of the heater/air conditioning blower motor in all speeds. If operation is not OK, service in the normal manner.
8. Vacuum the carpet, underlayment and floor of the vehicle of all water. Roll the carpet back to access the floor.
9. Position a heat lamp and fan so they are focused on the affected area of the carpet underlayment to speed the drying process.
10. Spray the affected area with an odor neutralizer. Refer to Corporate Bulletin Number 00-00-89-027.
11. When the underlayment is dry, reposition the carpet.

Parts are currently available at GMSPO.

For vehicles repaired under warranty, use: