Waterleak at Upper Corners of Deck Lid Hem Flange (Reseal Deck Lid Hem Flange)

Some customers may comment on water accumulating in the lower part of the deck lid between the inner and outer panels. This accumulation of water spills into the trunk area when the lid is opened.

This condition may be due to an unsealed deck lid hem flange at the corners of the deck lid near the rear window.

Important: It is often assumed that a deck lid waterleak source is from one or more of the mounting holes used to attach the rear spoiler. These areas should be checked for waterleaks but only in conjunction with the deck lid hem flange.

Diagnose the leak source and reseal the deck lid hem flange using the following procedure:

1. Spray water on the rear window as well as on the deck lid. When the deck lid is opened, determine if water is spilling out of the deck lid or leaking from around the weatherstrip area. If water is collecting in the lowest part of the deck lid, or at any location between the inner and outer panels, examine the deck lid hem flange.



2. To reseal the deck lid hem flange, dry the deck lid and flange area (see figure - Pontiac shown, Oldsmobile similar)

Important: Try to dry the hem flange as thoroughly as possible. The seam sealer used to repair the hem flange will dry clear; however, if any moisture is present, it will cure with a milky cast. The sealer will still turn clear but only after an extended period.

3. Apply a bead of 3M Ultrapro™ Autobody Sealant P/N 08302 U.S. (Canada use 3M Flexiclear™ Body Seam Sealer, P/N 08405) or equivalent, to the hem flange area, starting at the points of the deck lid (near the rear window) and extending six inches along both edges (see figure).
4. Smooth the bead with your finger or a no lint shop towel pressing the material into the flange, sealing it, and leaving a smooth attractive finish.
5. To avoid the flange area sticking to the rear window lower lace molding, allow the deck lid to remain open for at least an hour if humidity levels are low to moderate. Keep the deck lid open longer in high humidity levels.
6. Water test the repaired area by spraying a diffused spray on the rear window as well as the deck lid.

For vehicles repaired under warranty, use: