Porous Fiberglass? Roof leak advice requested

[DetroitBandit]

I am looking for some advice on troubleshooting a few very minor, but very annoying roof leaks. I have removed my headliner and installed new seals all around, the water drips are coming through the fiberglass. It sounds like troubleshooting these is a pain, so I am seeking advice from any who have had success.

The majority of the leaking is coming via two rivets (or some other structural piece in the fiberglass) underneath the rear of the door opening. It appears this piece holds some of the trim in the drain channel of the door. The red circle marks the area of leaking. Note: this leak occurs both when washing a stationary car as well as driving in rain.
37703

There is also a very small occasional leak closer to the windshield. I am going to remove the windshield trim piece today to see if a gap in sealant up there is causing it. I assume the leaks at the rear are coming in elsewhere? Does anybody have advice from experience in dealing with these? Is it likely coming in via underneath the T panel? Or through the drain channel of the door? Or where the fiberglass meets the rear windshield?

This forum has been a great help and 10105 is healthy and back on the road--but I can't install my new headliner until I have these leaks fixed!

Thanks,

Scott

[DMC5180]

About the easiest fix for porosity is to seal them with a resin mixture. The factory resin was either polyester or vinyl ester. For non-structural filler repairs you can use a 5-minute epoxy kit. Most hardware stores carry them in the glues adhesives section. Give the effected area a light scuff with medium sandpaper or scotch-brite pad. Mix small amounts on scrap cardboard with a Popsicle stick or equivalent.
Apply as necessary. If you want, you can drill a small hole where the drips occur and refill with the epoxy.

Something else, the factory put out a service bulletin for sealing potential leak points. You can tell if that has been done by all the black sealant covering or oozing from around fasteners in the roof. Your VIN would suggest it was done at the factory.

[David T]

About the easiest fix for porosity is to seal them with a resin mixture. The factory resin was either polyester or vinyl ester. For non-structural filler repairs you can use a 5-minute epoxy kit. Most hardware stores carry them in the glues adhesives section. Give the effected area a light scuff with medium sandpaper or scotch-brite pad. Mix small amounts on scrap cardboard with a Popsicle stick or equivalent.
Apply as necessary. If you want, you can drill a small hole where the drips occur and refill with the epoxy.

Something else, the factory put out a service bulletin for sealing potential leak points. You can tell if that has been done by all the black sealant covering or oozing from around fasteners in the roof. Your VIN would suggest it was done at the factory.

Get your hands on Service Bulletin ST-33-12/81 and go over it point by point. It should get any leaks fixed.

[DMC5180]

http://www.dmcnews.com/bulletins/ST-33-12.81.html

[DetroitBandit]

http://www.dmcnews.com/bulletins/ST-33-12.81.html

Hi Guys,

Thanks for such quick replies and good advice. My car does indeed have the RTV applied per that service bulletin, but it was clearly done at the factory and it probably wouldn't hurt to scrape off the old and deteriorating sealant and reapply.

As far as resealing the fiberglass where the leaks are coming through, am I hearing that it is not abnormal for water to reach the other side of this roof structure? That is, should I reapply RTV and attempt to stop water from getting between the stainless and the fiberglass first? Or is the car designed to have water up there and I simply have some issues with it leaking around these two fasteners?

Once again, thank you for all the help/advice. Hopefully I have these leaks resolved before I winterize my outdoor hoses for the year!

Best,

Scott

[David T]

Hi Guys,

Thanks for such quick replies and good advice. My car does indeed have the RTV applied per that service bulletin, but it was clearly done at the factory and it probably wouldn't hurt to scrape off the old and deteriorating sealant and reapply.

As far as resealing the fiberglass where the leaks are coming through, am I hearing that it is not abnormal for water to reach the other side of this roof structure? That is, should I reapply RTV and attempt to stop water from getting between the stainless and the fiberglass first? Or is the car designed to have water up there and I simply have some issues with it leaking around these two fasteners?

Once again, thank you for all the help/advice. Hopefully I have these leaks resolved before I winterize my outdoor hoses for the year!

Best,

Scott

The outer door seals are supposed to keep the majority of the water from getting into that channel so the first step is to see if the outer seals are in good shape and if not replace them. Next you make sure the channel is not obstructed by any dirt or debris. Finally go over all of the RTV sealing as per the Service Bulletin. Obviously if any of the existing is not there or coming loose you need to reseal the known possible leaks. Since you are doing this it would also be a good idea to remove the "Tee" roof panel and remove the cover underneath. Inspect the box area and clean it out.