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Big problem. Heater core?

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Old Feb 26, 2003 | 08:10 PM
  #1  
ice pac's Avatar
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Default Big problem. Heater core?

I ran the engine for a little while today and it ran well. However, I noticed that something was leaking from the passenger side floorpan. It turned out to be antifreeze(sp?). Coming from a bolt right below the dash on the passenger side footwell. It dripped down to a drain hole in the floorpan. I'm guessing it's the heater core. What should I do? I've heard they are a PITA to change. :banghead:

Thanks,
J.thib
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Old Feb 26, 2003 | 09:43 PM
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Default Re: Big problem. Heater core? (ice pac)

Your '81 probably has AC so that definitely increases the PITA factor.

You should probably check the archives; there've been a bunch of posts on this with very useful info & links.

On my '77 with AC, it wasn't a terribly difficult job, just time consuming. I had to pull the passenger and center dash sections out, then remove all of the duct work to get at the HC.

There are a couple of while-your-at-it tasks you may want to consider.

Since my carpet was soaked with anti-freeze, I pulled the seat and the carpet out (to shampoo it). While I had that side out, I decided to take the driver's side out too and put heat shielding down. BTW, I think it's a lot easier to work on the HC with the passenger seat out anyway.

I also bought a duct seal kit and replaced all of the seals on my ductwork while I had it out.

I did it in a weekend; probably 8 or 10 hours.

Oh, many suggest (wisely I think) that you should have the new HC pressure tested before putting it in. It a job I hope to never have to do again.

Good Luck.
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Old Feb 26, 2003 | 09:45 PM
  #3  
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Default Re: Big problem. Heater core? (jerryp58)

Ah yes, your C3 rite of passage. Good luck brother.

I say remove the dash, it will make it a lot easier. Good advice from jerry there.
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Old Feb 26, 2003 | 09:50 PM
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Default Re: Big problem. Heater core? (ice pac)

This will give you an idea of the chore in front of you.
http://www.corvetteforum.net/c3/juli...tCore_orig.htm
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Old Feb 26, 2003 | 11:01 PM
  #5  
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Default Re: Big problem. Heater core? (Chris@VetteFinders)

:iagree:

If you haven't reinsulated the floor, behind the dash and reseal the ducts, now is the perfect time to do so. Your A/C will work so much better. Have you leak checked the evaporator for the A/C yet??? Now would be the best time to change it, if you had to....
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Old Feb 26, 2003 | 11:15 PM
  #6  
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Default Re: Big problem. Heater core? (ice pac)

Yes that is a huge pain! If you dont have a heater core yet I saw one on ebay for $15 new. good luck :chevy
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Old Feb 27, 2003 | 01:22 AM
  #7  
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Default Re: Big problem. Heater core? (78PC L82_4SP)

Thanks for the tip. Sounds like a great deal.

Joey,
I think it's gonna work out for the best. I was gonna out in insulation in the next couple weeks. I have no idea how the A/c stuff works or how to test it. I was going to bring it to an A/c repair shop. But now I have some direction on what to do first etc. and If it's all out then I think I may be able to figure it out and maybe find the problem. How much does the A/C duct work usually run anyways?
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Old Feb 27, 2003 | 02:14 AM
  #8  
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Default Re: Big problem. Heater core? (ice pac)

i by-passed mine...don't need it..i get enough heat from the motor....
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Old Feb 27, 2003 | 05:46 AM
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Default Re: Big problem. Heater core? (ice pac)

When you change the heater core, make sure you test the new one on the garage floor bolted down in the plenum before installing the plenum. In other words, after you bolt the core into the plenum, connect the hoses to the core and run the engine until it reaches temperature. Check for leaks where the tubes are soldered at the core body. You will find that the tubes do not fit well in the plenum. When the tubes are clamped down, there is a chance the new core will leak where they are soldered at the core body. If they do, bring the new core back and demand your money back, but you will have saved yourself from doing this job twice.
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Old Feb 27, 2003 | 05:49 AM
  #10  
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Default Re: Big problem. Heater core? (ice pac)

I had the same problem with mine.
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Old Feb 27, 2003 | 10:56 AM
  #11  
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Default Re: Big problem. Heater core? (ice pac)

There is book out (if your into a little reading) called "A/C Strategies for the 68-82 Vette" that cover all the issues mentioned here. Certainly, you can by-pass it until you actually are ready to do it. Simply run one of the hoses from the outlet on the waterpump to the inlet on the intake manifold. End of leak.

Hans
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Old Feb 27, 2003 | 11:15 AM
  #12  
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Default Re: Big problem. Heater core? (78PC L82_4SP)

Yes that is a huge pain! If you dont have a heater core yet I saw one on ebay for $15 new. good luck :chevy
:nono:

I would not buy it unless I knew the quality and could test it.......You DO NOT want to it twice
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Old Feb 27, 2003 | 11:20 AM
  #13  
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Default Re: Big problem. Heater core? (Alwyn678)

I'll second all of the information above.

Mostly, check your evaporator core while you are there. I'm now switching to vintage air and removing all original stuff.

I've got the AC strategies book, an unused new heater core and all of the AC stuff from my 73 if anyone is interested:)

The book actually does help, but most of the information is available from forum members.
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Old Feb 27, 2003 | 12:15 PM
  #14  
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Default Re: Big problem. Heater core? (virtue4u)

When you change the heater core, make sure you test the new one on the garage floor bolted down in the plenum before installing the plenum. In other words, after you bolt the core into the plenum, connect the hoses to the core and run the engine until it reaches temperature. Check for leaks where the tubes are soldered at the core body. You will find that the tubes do not fit well in the plenum. When the tubes are clamped down, there is a chance the new core will leak where they are soldered at the core body. If they do, bring the new core back and demand your money back, but you will have saved yourself from doing this job twice.
EXACTLY - However, don't bother taking it back, as more than likely you'll keep getting leaks as you fit new cores into the frame (plenum). once it's in the frame, test for leaks, drain, and then solder with a propane plumber's torch. I feel more comfortable reinforcing the joints anyway regardless if they leak, since you will be stressing them once you put the core in place and slide the heater hoses in place.
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