I was washing my 83 Caprice wagon and noticed that the rubber (plastic?) pieces underneath the roof rack rails are starting to crumble away. Before I remove any of these strips to see what is going on underneath (and cause potential leaks) has anyone come up with any replacement solutions?
I found an eBay auction for an entire roof rack, and according to the description, those pieces are plastic: I predict removing my rails will make the problem exponentially worse.
There's been some discussion about this in the past: 1989 Buick Electra water leak | Station Wagon Forums I don't know if there's a "best" solution sorted out yet.
Interesting... I think the best solution would be some kind of thick rubber strips. Although I don't how the screws are attached to the roof -- i.e. if there is a nut on the underside, or where the threads are. I have no leaks (that I know of) so I think I'll leave well enough alone for now.
My roof rails were just attached with sheet metal screws. I reinstalled them with a blob of silicone goop at each screw. That set on ebay is exactly what mine looked like. Flexible plastic, maybe polypropylene?
I would lean to the gaskets being an ABS blend to give them a degree of flexibility and durability, the material initials should be moulded right into the gaskets, PP, ABS, ABS-PC.
The Resin Identification Code standard didn't start until 1988 but took years to become widely used. I would guess them to either be PP or more likely HDPE.