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Heater Core Replacement

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Old Oct 1, 2002 | 08:45 PM
  #1  
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Default Heater Core Replacement

The heater core in my 78 is leaking and I believe its time to replace. What's best way to remove dash pad and retrieve heater box and core?
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Old Oct 1, 2002 | 09:00 PM
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Default Re: Heater Core Replacement (hunt4cleanair)

Depends on if you have a/c or not. If not then you can get it out from the engine compartment-check the search option for this because it was just up last week or so with great pictures from Paul79.
If you have a/c then check Juliets web page for details. I pulled the box on both types and the a/c cars take time to do.
Good luck,
Gary
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Old Oct 1, 2002 | 09:08 PM
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Default Re: Heater Core Replacement (hunt4cleanair)

Do you have A/C? If not, take it out the front.



If yes to A/C, here is the link.
http://www.corvetteforum.net/c3/juli...tCore_orig.htm


[Modified by paul79, 9:17 PM 10/1/2002]


[Modified by paul79, 9:23 PM 10/1/2002]
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Old Oct 2, 2002 | 12:10 AM
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Default Re: Heater Core Replacement (gtr1999)

It's an air car and there are differences between early sharks and late sharks. I'll do some photos as well to document differences. My dash is one piece...no big section on passenger side to drop, no brace but interesting to study Paul's photos.

I've already got glove box out, center console, radio and duct work.
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Old Oct 2, 2002 | 05:52 PM
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Default Re: Heater Core Replacement (hunt4cleanair)

Really, my pics would not be helpful for an A/C car.
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Old Oct 2, 2002 | 10:26 PM
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Default Re: Heater Core Replacement (hunt4cleanair)

I just got mine out last night (78 with AC)...For me it was PITA. I wound up removing the seats, the console, the inner windshield frame work (to get the dash out). the ductwork. My hoses were attached with screwed clamps which I couldnt get off because they were well up in the recessed area. My solution was a recipercating saw and cut the hoses. The extra thickness of the hose on the core inlet and outlet pipes made pulling the core assembly much harder than it needed to be.

I was deliquent in marking & bagging all the screws that I eventually wound up removing, I am cleaning as much as I can while I got it apart. I also bought a gasket/seal kit. Hope I find all the screws when putting it back together !!!

There is another recent post that warns about stressing the inlet and outlet pipes when reinstalling.

While I have the dash apart I am going to replace the dash pad and install an original radio I picked up on eBay.

Good Luck

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Old Oct 3, 2002 | 12:06 AM
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Default Re: Heater Core Replacement (paul79)

In retrospect I think that I probably could have done the heater core myself on my AC 70, but at the time I was sick, it was winter and I just was not in the mood to deal with it so I had Tony's Corvette do the swap for me. They took the photos I have on my website detailing the process. ~Juliet
http://www.corvetteforum.net/c3/juli...tCore_orig.htm
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Old Oct 3, 2002 | 12:18 AM
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Default Re: Heater Core Replacement (molchaser)

I got mine out without removal of dash pad or the driver's seat. Hoses came off with a little prying and a twist once the screw clamps were loosened. It's a 32k car so the wear and tear had not taken its toll like a high mileage car.

I used baggies separating the screws (trim, console, duct work, etc) so if you need some guidance...drop me a note. I didn't get the gasket reseal kit...what's in it? I've got to pick up heater core tomorrow. I'll get some wx striping from Lowe's for the duct seals and caulk for sealing the box up

hunt4cleanair@earthlink.net
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Old Oct 3, 2002 | 11:33 AM
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Default Re: Heater Core Replacement (hunt4cleanair)

Mine was quite a nightmare :eek:
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Old Oct 3, 2002 | 11:46 PM
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Default Re: Heater Core Replacement (hunt4cleanair)

I haven't unpacked the seal/gasket set yet. I looked at my replacement core and it looked like the inlet & outlet pipes were cold soldered. A budddy of mine has a big soldering iron that he says he can control better than a torch and is going resolder these before I reinstall.

However here is addy for Dr Rebuild where I got the seal/gasket kit.
http://www.docrebuild.com/dr-r-web/AC-HTR-SEAL.HTML

:)


[Modified by molchaser, 9:47 PM 10/3/2002]
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Old Oct 4, 2002 | 12:01 AM
  #11  
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Default Re: Heater Core Replacement (molchaser)

molchaser, pressure test that puppy before you stick it in! I'd bet that 10%-20% of the replacement cores leak on install! It really doesn't matter who they come from either. A radiator shop will pressure test it for a couple of $, if you don't have a radiator shop nearby, pressure test it yourself.
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Old Oct 5, 2002 | 08:06 AM
  #12  
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Default Re: Heater Core Replacement (Smokehouse69)

Best tip yet! And sure enough...the sucker failed the test. The radiator shop was closed until 10/7 so I filled it with water and put the air hose to with my finger as plug.

I spotted water running from the smaller tube where it was soldered to the core. It was a Modine.
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Old Oct 5, 2002 | 08:30 AM
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Default Re: Heater Core Replacement (hunt4cleanair)

Wow! Just think of all the time you saved by testing it. If they leak, that is where it is. Had you already installed it in the cradle? If not, make sure you do that on the next test. The tubes do not fit nicely in the cradle without a little force to separate the tubes. That is when the leak may develop. So make sure you test the core installed in the cradle.
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Old Oct 5, 2002 | 10:59 AM
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Default Re: Heater Core Replacement (virtue4u)

Hey Virtue4U:

Sharp photo! The trophy that is...Ha, ha. Sounds like you must have done this to and indeed the test was in the cradle. And indeed, the tubes had to be bent to accommodate the cradle housing...I didn't like doing that.

I see you're car is a 77...is it a one-piece dash? Or, does the passenger side have screws to drop the dash and reveal the ductwork? I'm doing some research on the one-piece dash.

Thanks
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Old Oct 5, 2002 | 11:14 AM
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Default Re: Heater Core Replacement (hunt4cleanair)

Hey where are you guys getting the heater cores. I was looking at Autozone online and they are $33.99. I was thinking of running down and getting one while I still have the engine out. Now is the perfect time.
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