I'm changing out my stock heater core, one of the casualties of leaving old antifreeze in for too long. I've got the box and core out, and now I need to re-install everything with the new core. Most of the foam gaskets, except for those on the outside edge of the box, are dried out and cracked beyond repair. Does anybody sell replacements, or is black RTV silicone acceptable for re-installation? Also, the inlet/outlet pipes on the stock core were bent outwards quite a bit in order to fit into the holes of the heater box. Will bending the pipes in the same manner damage the new core?
Just as I was about to post about Skylark and GS, I noticed that you were asking about 67 Riviera... Good luck on that deal; although there are some specialists catalogs for Riv's, I'm not familiar enough. Most cars used a seal made of either foam rubber (later cars) or a sealant called 'dum-dum' It is available from 3M in grey or black, often called strip caulking, comes in a box I'd say about 2 pounds, 2 inch by 2 inch by 8 inch. Common available in hardware stores is weatherstrip caulking strip, similar but lacking a string in the middle. One downside to using RTV is that it is actually acidic, and requires moisture in the air to form correctly. Don't know about the bending of the tubes, but probably NOT advisable; that is the weakest area where the tube attaches to the shell of the heater core. ---------- Post added at 02:01 PM ---------- Previous post was at 01:21 PM ---------- After posting my last, I found a trusted reference... While not addressing your specific model, it is a good guide in general. http://www.buickperformanceclub.com/CowlLeaks.htm
Thanks for the info. I went to a hardware store, and got some regular 100% silicone sealer. I only needed to seal the aluminum frame inside the heat box, and that one line of gasket where the box enters that port on the firewall. Everything's back together now, and I've pressure tested it for leaks. Looks good. I'll fire it up tomorrow morning after the silicone has cured.
Here's some shots of the box & firewall when everything was taken out: I had to wipe down the firewall and the bottom of the evaporator box to get all the gunk off which had seeped out of the leaky heater core, but it cleaned up well. Everything is back together and works fine. My blower feels like it has a lot more push now, and the heater is functioning at 100%.
