Heater core replacement help.

[Gerald Lee]

Hello All,

Well, this week's project is to replace the outer heater box which someone had grossly tried to repair. Upon inspection of the heater core I found that it has been leaking. I started to try to remove the inner box so I could get the core out, but I'm finding that it is not as easy as it looks. Will I need to remove the dash to get the inner heater box out so I can replace the core or do I need to be more patient and massage it out? I'll admit I'm a real novice to this procedure. I looked in the AIM guide and researched the NCRS archives and found no info. So once again, thanks in advance for any advice!

Gerald

[Paul B.]

G.Lee What year Corvette? A/C?

G.Lee What year Corvette and do you have A/C?

[Gerald Lee]

Re: G.Lee What year Corvette? A/C?

Dah?

1966 Roadster without A/C.

Thanks

Gerald Lee

[Joe L.]

Re: G.Lee What year Corvette? A/C?

Heater core replacement on any 63-82 Corvette requires that the dash be removed, at least partially. Usually only the right side/center dash requires removal, however. This is not an easy job and will require considerable time and effort. I strongly suggest following the procedure as exactly outlined in the Chevrolet Service Manual. Unfortunately, there are no shortcuts.

Be glad that you don't have a 90-96 C4, though. Replacing the heater core in these vehicles is a MONUMENTAL task. I've replaced the heater core in my 69 several times in the nearly 30 years that I've owned it. A big job, and very similar to your 66 with respect to heater core replacement, but with time and patience it's bearable. For my 92, however, when it's time for heater core replacement, I think I'll just get a C5.

[Jack H.]

Re: Heater core replacement help.

I tried to post a reply yesterday, but must've 'mis-moused'....

My input was take a shot on a quick fix before you break your back on the heater core replacement. Frequently, leaks happen because someone tugged too hard/wrong when replacing heater hose(s) and there's a tiny rupture at the nipple junction to the core.

Don't remember what's in the mid-year shop manual, but on shark cars the CSM (chassis service manual) is pretty clear about the preferred method of hose removal. Because hoses tend to 'fry' onto nipples, they suggest you take a razor blade and gently cut a longitudinal slice, peal back the hose from the nipple and shorten the hose for re-assy. This prevents excess lateral stress at the nipple/core junction.

So, I suggested: (1) doing a real good/thorough back flush of the heater core that exists, then (2) dropping some aluminum cooling system rated anti-leak dopant (pellet or liquid form -- ask your local/trusted auto parts house or mechanics for their recommend) and see if you can save what you've got. We're talking a few minutes and maybe $5 here to give it a try.

My '71 SB A/C core leaked modestly a few years back because yours truly did NOT read the CSM when he pulled the heater hoses! I gave the leak stop method a try and it's held like a champ ever since with no temp build-up problems AND three annual heavy duty cooling system flushes!!!