Does anyone know what other product will work to seal the heater core to the heater box. I'm talking about the seal that the heater core rests on inside the heater box.

When I put the heater core and box together I used a foam seal that came in a kit. I had to remove the heater core after running the engine and the foam is flat and has shrunk from the heat.

If anyone has any ideas on another way to seal the heater core to the box, please let me know.

Pipe dope or similar caulk that does not harden. Inspect any origional box and this will be evident.

I bought some of the stock foam rubber to go around the heaterbox. Glued it to the box with 3M weatherstripping and then used Aircraft sealant (the black goo) around the edges. Worked pretty well for me.

Stretched butyl tape or 3M strip caulk will work.

Well I went ahead and used the seal that came wit the kit I bought. After several days the seal returned to original size. Hopefully I will not have to remove the heater core again. Thank you guys for the replies. As far as the 3m strip caulk, would'nt it melt and turn to goo?

Dave's talking about the stripcaulk that is similar to non-hardening door seal (household type). Neither harden and they maintain a constant consistency. Like I said look at any origional sealer in a heater box and it is not rock hard. No, they won't reduce to a drip-like viscosity when exposed to heat.

Sorry, I didn't read closely enough. I was thinking heater box to firewall :clonk:

lol....I knew about the 3m strip caulk for the seal on the firewall, but thanks for info. :thumbsup: