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Old Dec 21, 2011 | 07:12 PM
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Heater core question

Hey guys, I need a new heater core in my 79 F250. I'm thinking of trying it myself, but I have a couple of questions before I give it a go.

There are two options when I look at buying a new heater core, a standard heater core and then a high power one(I forget what they called it at the parts store). How do I tell which one that I need?

How hard is it change? I have a couple of threads I searched for and looked them through, it doesn't look to hard. But you never know.

I'd also greatly appreciate any tips or tricks anyone has. I've never change one of these before.

Thanks!
 
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Old Dec 21, 2011 | 07:22 PM
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I just finished mine this past weekend. Now, my AC unit is in the engine compartment. I think yours, if you have one, is under the dash, but I could be wrong. That could make it harder if you have to work around that. If you don't have AC to worry about, just go by the threads and you can do it without any trouble. Mine took me about 2 1/2 hours total and I'm hardly a pro at this. I didn't know that I had the wrong core until I actually got my old one out. Advance Auto didn't give me any troubles about the exchange and I finished up pretty quickly after that.
 
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Old Dec 21, 2011 | 07:22 PM
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It will say "HIGH OUTPUT HEATER" near your heater controls (unless your dash bezel's been swapped out) otherwise the hi-output core is 6x8" and the standard core is 6x6".

 
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Old Dec 21, 2011 | 11:22 PM
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Mine doesn't say high output heater on it, but the bezel could have been changed at some point.

I'm going to give it a go tomorrow.
 
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Old Dec 22, 2011 | 07:33 AM
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If ur lucky and don't have a/c at all, its a breeze. Good luck with it
 
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Old Dec 22, 2011 | 08:22 AM
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And a hint to make the removal easier. There's a bolt up under the dash on the lower right hand side. With that removed the dash pulls out a little to give you more room to slide the heater box out.

.
 
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Old Dec 22, 2011 | 09:01 AM
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Originally Posted by OldStyle
And a hint to make the removal easier. There's a bolt up under the dash on the lower right hand side. With that removed the dash pulls out a little to give you more room to slide the heater box out.

.
Absolutely right. It took me 30 minutes to do mine without A/C.
 
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Old Dec 22, 2011 | 09:17 AM
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Blow the heater core out with air before removing the box from the firewall. That way the antifreeze that is left in it won't go all over your floor.
 
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Old Dec 22, 2011 | 02:56 PM
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Originally Posted by mark a.
Blow the heater core out with air before removing the box from the firewall. That way the antifreeze that is left in it won't go all over your floor.
Amen to that :thumb:
 
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Old Dec 22, 2011 | 09:32 PM
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I just got done with it. It took me a couple of hours and some swearing, but I got it done.

What really sucks is it is still leaking coolant. I has to be coming from on the two hoses at the firewall. The clamps are tight, I'm going to replace the hoses tomorrow and hope that fixes it. The funny thing is, is that was probably the only thing wrong with it.
 
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Old Dec 22, 2011 | 09:42 PM
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Originally Posted by Cory281
The funny thing is, is that was probably the only thing wrong with it.
The truthful thing is, one less hassle down the road, and one more warrantied part on the rig!
 
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Old Dec 22, 2011 | 09:55 PM
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Originally Posted by Cory281
What really sucks is it is still leaking coolant. It has to be coming from the two hoses at the firewall.
Trim an inch off the end of the hoses so there's new material for the clamps to bite into, while the hoses are still hot cinch down on the clamps a little more, they'll usually stop leaking on their own after a few heat cycles.
 
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Old Dec 22, 2011 | 10:08 PM
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I'll do that, thanks for all the help guys!
 
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