C3 heater core replacement

[Carl H.]

Is the air distributor glued to the passenger side of the firewall? I have removed the 4 nuts from the studs that go through the firewall, have the instrument cluster out, console pulled back just like the service manual says to do, but the air distributor won't budge. GM service manual does not mention any other bolts. Have been reluctant to apply lots of force until I know for sure that I am not going to break the thing. Any advice would be greatly appreciated.

[Harmon C.]

Re: C3 heater core replacement

It has sealant on it and may be stuck tight but if all the nuts are off it should come loose. Make sure their are no nuts under the fender on the housing around the fan.

[Tom R.]

Re: C3 heater core replacement

Carl:

I just did my 78 and once I removed all four bolts...did have to exert some force to pop it off the firewall...but it did pop off! I can't say mine had sealant on it but the collar gasket was tight perhaps from 25 years to snugging up to the firewall.

What year are you working on?

[Eric Fairclough]

Re: C3 heater core replacement

Carl, I did my 72 with air and it had a giant rivet at the top that i found after i unbolted the box and could not take it out. There was'nt enough room to drill it with a regular bit so i had to buy a 1 foot drill bit and drill it out then the heater air box fell out. This was factory on mine because the heater core was orginal. Eric

[Jim T.]

Re: C3 heater core replacement

Carl I am going from memory here of doing a heater core replacement on my 70 several years ago. I had no difficulty in removing the assembly from the inside. I don't remember the exact count of bolts removed, but make sure you remove the nut on a bolt that does not have a conventional head on it. This should be on the right side area of the of the heater core container. The nut connecting this stud is on the engine firewall side. Be very careful with your instrument guage cluster bezel, it is very easy to break at its disigned weak point and is expensive to replace.

[Jim T.]

Re: C3 heater core replacement

You might like to view Juliet's heater core removal pictures on the 70 Corvette Registary.

[Carl H.]

Re: C3 heater core replacement

P.S. Forgot to say mine is a 73 without air conditioning.

[Paul L.]

Re: C3 heater core replacement

Without A/C. It pops out. You may find a lot of goop there, however.

[Carl H.]

Re: C3 heater core replacement

Thanks guys, project completed successfully.