740 gas cap door water leak

1986 744 Turbo.

Water collects in the left rear of the trunk, in the recessed area.

I thought it was leaking through the tail lights, but the new gasket is sealing it: upon inspection I see water is leaking from under the gas cap door assembly.

I cannot tell how the leak is caused; thinking maybe the rubber surround piece that surrounds the gas cap may need to be sealed around the edges?

Noticed the drain hole underneath seemed plugged, so I cleaned it.

Any suggestions?

OH man... like, it's leaking through one of the metal seams? Or... I'm not even sure what gasket is there that would leak?

If it's inside your fuel filler flap, at least you have the benefit of it being concealed so you could apply (temporarily) a coating of grease to see if that stops it, and then of course go back with clear silicone or RTV? Alternatively, you could just go with that.

You sure it's water and not fuel? And you're sure it's coming in from there and not up from the bottom?

i know fuel and silicon caulk aren't exactly friends but you could always try cleaning the area and applying a thin bead of caulk.

hikerguy said:

i know fuel and silicon caulk aren't exactly friends but you could always try cleaning the area and applying a thin bead of caulk.

Click to expand...

I was thinking this too, but also... it shouldn't (ideally lol) interact with fuel no?

Permatex Power Bead Black RTV <--That works well for that kind of stuff