1998 Park Avenue trunk leak solved

[yutz1]

I discovered a trunk leak in my 1998 Buick Park Avenue. After peeling back the carpeting and insulation, I discovered the cause.

On the passenger side, there is a black plastic pressure relief valve. It is located approximately inboard of the marker light on the bumper cover. Its purpose is to vent excess positive pressure developed from ventilation. It pops out behind the bumper cover upon releasing two tabs on top and two on bottom.

It has two flaps made of a thin plastic material, which are designed to sit flat against the housing when closed. There was a white water line across the bottom flap, and dirt could be seen on the trunk sheet metal near this valve. Water had collected in the spare tire well.

GM part number for this valve is 22702778.

Hope this helps someone else who experiences this issue. It took quite a while to find this after pulling tail lights, checking weatherstripping, etc.