C2 Heater Core Replacement

[Mark W.]

I'm getting a hint of anti-freeze smell and some minor fogging from the defroster (no wet carpet) in my '66, so I've ordered a new heater core. I've got several books that cover removal and installation, which looks pretty straight forward. However, most of the work I've done on this car never turns out to be straight forward, so I was wondering if anyone has any helpful hints for me on this project.

[Harry Sadlock]

Re: C2 Heater Core Replacement

Mark, there are really two answers to the question. The answers depend on what you intent to do with the car. If the car is a long term keeper or not. In either case no matter how slow you proceed, go slower so as not to break the studs on the inner box.

If the car is not a keeper, just pull what you need to replace the core. including the carpet.

If the car is a keeper:

Pull the carpet.

Put Plastic down to catch dripping fluids.

Pull the glove box, inspect the glove box light and wiring.

Take pictures of the Trim and Vin tags for future reference.

Disconnect the vent cable, clean it, paint the metal part that attach's under the dash, then lube for easy operation.

Make a copper U to connect the water hoses to each other when you disconnect them from the outer box.

Have a bucket under the car to catch the anti-freeze.

Have some tape to tape the water hoses out of the way.

Remove the battery.

From a weight standpoint I suggest you pull the fan motor first.

Remove the nut from the inside box that is under the wiper motor.

Remove the two cables from the inner box. tape them out of the way.

Pull the electric cable from the cowl side of the box.

Loosen the Outer Box Nuts, have someone inside to support the inner box when the nuts are removed.

Slowly and with no angle pull the inner box into the interior of the car, then get it out of the car.

The Shop manual is a good guide to change the heater core.

When the heater core is out, consider rebuilding the inners of the inner heater box. The seals are probably dried out and have fallen away. There is probably a good deal of rust on the metal interior and the flaps. Dr. Rebuild sells a good set of seals.

Remove the right vent grill and the flapper and clean the area with a vacuum and ensure the drain hole is clear at the bottom. This is where 39 years of junk has accumulated.

Now, reverse the process to put it back together. Take lots of pictures

I probably forgot a few items and others will chime in. It is not complex to do, it just consumes time.

Good Luck

Harry

38513

[Rob A.]

Re: C2 Heater Core Replacement

I've done a several. The chevrolet chassis service manual for your year car has good instructions on replacing the core, like attaching the nut that holds the left side of the inside heater box to the firewall stud first when re-installing it. If you have the manual, don't skip any of the steps, there really aren't any shortcuts. It will also prevent you from removing things that aren't necessary. There are quite a few things to remove(like the glove box) and no real short cuts, and that's why a shop will charge so much a for the job. When you attach the new hoses to the core on the engine side, be careful, the tubes are only soldered on, and you don't want to break one at that point. Hope that helps.

[Bruce Boatner]

Re: C2 Heater Core Replacement

Mark,

In addition to the information in the prior posts, as with any underdash work I recommend that you pull the passenger seat. Takes only a few minutes and your back will thank you for it later. I also recommend the Doc Rebuild kit.

Bruce

[Frank H.]

Re: C2 Heater Core Replacement

I'd say a new inspection tag for the inner case while your their,last one I did the replacement core didn't look too good so I took them both to the radiator shop,and he looked at it and laughed and said 35.00 to recore the original tanks on a new core,and he sent the NEW one back.

[David W.]

Re: C2 Heater Core Replacement

There is also a good article in the restorer. I can email it to you if you'd like.

[Mark W.]

Re: C2 Heater Core Replacement

Thanks to all for the advice. I have all the manuals mentioned and the Restorer article should be even more help.

[Jim #42767]

[Mark P.]

Re: C2 Heater Core Replacement

Two questions requesting clarification on a heater core/box installation on a '65. I got the gasket kit and need direction on what to do with the grey foam gasket the goes on after the black gasket on the interior of the firewall. It appears to go on the outside of the box, conforming to the contours of the exterior, rather than completing a seal of any kind. Am I wrong? If that's the way it goes, why is it there (just for looks?)and do you use adhesive to hold it in place? If so, a spray 3M adhesive?

Other question: I've seen different illustrations on what to do with the "donut" ring seals that go arouond the heater core outlets on the engine side. The most popular method shows them on the outside of the heater box fiberglass cover, but I've seen one descriptiion that says you should put them on the inside of the cover after the black seal and between the cover. Neither option seems to seal it particularly well. I guess I could really jam them in there, but don't want to botch the whole deal. I'm wondering if I should use an adhesive and what that should be....

Too many questions, too little knowledge. I'd appreciate any input.