Sealing between AC heater core support and fiberglass distributor box?

[Robert W.]

[Gary J.]

Re: Sealing between AC heater core support and fiberglass distributor box?

Yes there is a foam seal. It is in Dr. Rebuild kits. If you look at his site you will see the seals for the box. So far I have rebuilt 3 A/C boxes.

[Rocco S.]

Re: Sealing between AC heater core support and fiberglass distributor box?

I just completed a heater core replacement on my '67 A/C, L79 coupe. It uses a foam seal. See the attached photo. I glued it in place with Contact Cement.

[Robert W.]

Re: Sealing between AC heater core support and fiberglass distributor box?

Hi, I'm talking about the area between the metal heater core support and the fiberglass inner box. Not the thick inner box to firewall seal as shown above.

[Peter M.]

Re: Sealing between AC heater core support and fiberglass distributor box?

Hi Robert,
When I put mine back together I used some strip seal (AKA dum dum), there were remnants of it there, but it had been apart before.
Hopefully Gary Jaynes will comment.
Kind regards

[Rocco S.]

Re: Sealing between AC heater core support and fiberglass distributor box?

You could use 3M black strip calk (rope dum-dum). But I thought the high heat may make it a sticky mess. There was remnants of a gray calk material when I disassembled the heater core assembly. So I decided to use white plumbers putty. Its inexpensive and is easy to mold into rope. I think it is important to use something on the edges of the heater core to keep it from rubbing and wearing a hole in the tanks or core. I also used it on the flange when sealing the metal heater core assembly into the plastic box. See photos of the heater core cover with original gray sealant and the completed box showing the white plumbers putty on the flange under the foam seal.

[Robert W.]

Re: Sealing between AC heater core support and fiberglass distributor box?

Thank You! I'm planning on reassembling tomorrow. Mine won't look as clean as these pictures do though...

[Greg H.]

Re: Sealing between AC heater core support and fiberglass distributor box?

Hi Robert,
This is my 67 box and it looks like some type of liquid sealer was used for sealing the metal mating surfaces.

Maybe that universal roofing sealer?

[Greg H.]

Re: Sealing between AC heater core support and fiberglass distributor box?

Hi Rocco,
I have looked for a paint source that will match the metallic black that we find on our AC plenums and under dash parts. Looks like you have found the right paint. Please reveal your source.

Thanks Greg

[Gary J.]

[Rocco S.]

Re: Sealing between AC heater core support and fiberglass distributor box?

Greg,
I would love to reveal my paint source--but I did not refinish the box. The car only has 54,000 miles and the box was in near perfect condition. Just very dusty. It only required a good cleaning with spray 409 cleaner and a stiff brush. Below is a photo of the of the box right after cleaning. I guess I should consider myself lucky it was in such good condition.