Question: C2 Heater / Defroster Box Internal Seals

[Jeff H.]

Hello group,
Has anyone out there ever had a C2 ('64 non A/C) heater / defroster box apart? I'm rebuilding mine, and purchased a seal kit for it. Aside from the big seals for the dash, there are 3 foam mode door seals in the kit. The small one obviously goes on the defroster mode door. The other 2 are identical size (approx. 3.5" X 5") and would seem to fit the heater / vent mode door behind the heater core. My question is why 2 seals? Does that mode door require 1 on each side? Not sure why it would. Or does the 2nd seal go elsewhere? There is another mode door halfway between the ends of the box, but it is a smaller size, is rather inaccessible and has felt seals on both ends. Where does that 3rd rectangular foam seal belong?? Perhaps back in the spare parts box.
Thanks,
Jeff Hanson

[Keith B.]

Re: Question: C2 Heater / Defroster Box Internal Seals

Dr Rebuild has a good diagram in his catalog of the heater boxes

[Stuart F.]

Re: Question: C2 Heater / Defroster Box Internal Seals

I applaud you for trying to replace the inner seals. Some of us (myself included) only open up the heater box because we have to in order to change out a leaking heater core. In the process, we buy a seal kit because it is a must to reseal the box to the firewall, i.e. you can't save the old seals during removal. For me, I looked at the inner seals and they looked like they were in good enough condition to last at least through my life time so I chose not to touch them.

Good luck.

Stu Fox

[Jeff H.]

Re: Question: C2 Heater / Defroster Box Internal Seals

So, Stu, what did you see inside your heater box as related to seals? Did the big trap door behind the heater core have a foam seal on both sides, or just on the side facing the core?
Thanks,
Jeff

[Timothy B.]

Re: Question: C2 Heater / Defroster Box Internal Seals

Jeff,

I could be full of hot air here but I think the air door needs a seal on both sides because it keeps heat out when using the vent feature or it keeps vent air from bypassing the core when calling for full heated air. :-)

[Harry S.]

Re: Question: C2 Heater / Defroster Box Internal Seals

Yes, both sides.

[Stuart F.]

Re: Question: C2 Heater / Defroster Box Internal Seals

Jeff;

Here are the references I used to replace my heater core:

1) Fall of 1999 issue of "The Corvette Restorer", Vol.26, #2, article by Randy Merzdorf on "Mid-Year Heater Core Replacement".

2) "Corvette Magazine", January 2003 Issue, Pages 90 thru 95, article entitled "Rotten To The Core".

Jeff, I reviewed each of the references and in both cases they elude to replacing the door seals only if they were damaged by leaking coolant. A lot of help, right? Neither explained how to do it or exactly where they were and what function they performed. I also checked the photos I took during my procedure and they weren't of much help either. I didn't focus on the flapper doors as I determined early on that they looked good functionally (undamaged) and that they might not remain that way if I attempted to replace them.

Stu Fox

[Greg C.]

Re: Question: C2 Heater / Defroster Box Internal Seals

Has anyone experience in taking out the individual diverters/gaskets inside the box?

I got mine out, and am working on cleaning up the box and replacing the seals, but for the life of me, I can't figure out how to get the diverters out of the box itself. The diverters seem to be spot welded to the rotating mast.
Heater-Diverters.JPG
Am I seeing it wrong?

I searched this site and the web in general, but couldn't find anything. Lots of people replace heater cores, but I can't find anything on this sub assembly.

Thanks, in advance.