WATER LEAK AT PLENUM CHAMBER DRAIN COWL AREA

MODELS AFFECTED: 1990 RIVIERA

Some 1990 Rivieras may experience a water leak in the left front or rear floor pan area. This condition may be caused by improperly installed expandable sealer in the plenum to body hinge pillar inner panel behind the left front wheelhouse. This condition was corrected in production at the following VIN breakpoint: LU402641.

To repair this condition use the following procedure:

1. Remove left front wheel.

2. Remove screws that join the stone shield to body at wheelhouse. Refer to Item 1 in Fiaure 1.

3. Remove wheelhouse stone shield to expose plenum drain area that mates to hinge pillar. Refer to Item 2 in Figure 1.

4. Cut sealer flush to metal and expose opening of the metal-to-metal contact where sealer should be. Fill this area with 3M brushable seam sealer, number 08656 or equivalent. Refer to Item 1 in Figure 2.

5. Water test plenum drain area after repair.

For warranty purposes use Labor Operation T6403 at .6 hour when completing steps 1 through 5.

If the carpet is wet or an odor is present in this area, then it will be necessary to remove the floor carpet, dry it, and replace the carpet insulator using the following procedure:

6. Remove driver's side kick pad only, right kick pad if removing complete carpet.

7. Remove seat.

8. Remove driver's side carpet only, completely if left side of carpet is wet.

9. Remove carpet insulator and possibly replace if saturated or odor is emitted. Insulator, P/N 20464593, is currently available from GMSPO (ordered by square foot).

10. Remove shift console when complete carpet and carpet insulator must be removed.

11. Wash floor pan with disinfectant.

12. Dry carpet.

For warranty purposes use Labor Operation T6399 at 2.8 hours when completing steps 1 through 12.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.