C3 Heater Core Replacement

[James Keddie]

I'm replacing the carpet in my '70 (non-air) and discovered that the padding under the dash on the passenger side is a little damp. When I replaced the heater hoses last year I had a problem with the heater hoses leaking at the core tubes (tower clamps) so I'm not sure if the coolant is leaking at the hoses and running into the interior and running down or if the core is actually bad. But as long as the seats and carpet are out, thought it would be good insurance to replace it now.

My questions are: is this heater core still available from GM, and if not, any recommendation on where to get the best quality replacement? I have looked in the archives and it sounds like they are not US made any more, at least for the mid-years.

Also, since my car is non-air, can this core be replaced entirely from the inside without removing the heater box under the hood?

Thanks in advance!
Jim 42765

[Jim T.]

Re: C3 Heater Core Replacement

Your heater core can be removed from the inside. This is the way the service manual gives. A new heater core can be obtained from several sources like Dr. Rebuild and all the Corvette parts venders.

[kelly theaker]

Re: C3 Heater Core Replacement

can you not recore it?

[Dick W.]

Re: C3 Heater Core Replacement

Should also be available from NAPA, Carquest, O'Reilly's, etc auto parts stores. I would stay away from the discount auto parts chains for items like this.

[James Keddie]

Re: C3 Heater Core Replacement

Kelly,
Yes, I guess I could recore the one that's in there now, but figured a new one would be cheaper and more reliable. It doesn't sound like a job I want to do twice. Thanks for the suggestion.

[Larry M.]

Re: C3 Heater Core Replacement

James -

I replaced the heater core in my '72 non-air coupe a number of years ago, using an aftermarket unit. I removed the underhood heater box (I don't recall if I believed I needed to, or if I did so to make the job easier), and with it out of the car, was able to give it, the blower motor and the surrounding firewall area a more thorough cleaning and detailing than I had previously been able to accomplish. It was a satisfying experience to scrape of years of crud and dust from the bottom of the box, and to shoot the blower motor with a fresh coat of 'probably-incorrect aerosol black'.

Best of luck with your project.

Larry, #10731

[Paul L.]

Re: C3 Heater Core Replacement

I have done that job twice on a non-A/C C3. In my opinion the easiest way is through the firewall.