Here is the background for my question - When the engine went on my 78 F-100 302, I replaced it with a remanfactured engine. In doing so I removed the AC completely (it was shot also). Everything that was a part of the AC was removed down to about 3 inches of intake & outlet hose sticking through the firewall. And I even took a hose and flushed out the evaporator core.

The heater core had long been disconnected due to the core leaking, so I went to replace the core. What a nightmare!!! After cutting & tearing the heater box apart I finally removed the heater core. Now I am ready to install a new core.

Suddenly I have been struck with these thoughts. The heater core and the evaporator are both just small radiators - correct? I did notice in the LMC catalog that an evaporator core is considerably more expensive than the heater core - is it constructed better or of better materials?

But now after all this discourse I get to the question for you guys - could I just connect the heater intake & outlet hoses to the two hoses going to the AC evaporator core? Then instead of blowing cold air I would blow hot air? I know someone is going to tell me this will not work, but please tell me why not. As of this moment I see no reason why it would not be feasible.

Let me know what you think.
Thanks,
CB3

 

A year or so ago someone posted a question about a truck they had just bought. To make a long store short, a previous owner had done exactly that. To bypass a leaky heater core (presumably) they had run the heater hoses to the A/C evaporator.
It apparently worked but confused the daylights out of the new owner.

Just a note, the evaporator is made to handle much higher pressure than the heater core. It is also has a much larger surface area.

 

I had no problem taking the evaporator and heater core out today.

Why did you have to cut it apart? Oh was the box still installed?

Yea I know having it on a tailgate made it a ton easier....

 

Nice pictures. That sure makes it easier to see what's what and how it all
fits together.

Check your PM's.

 

Yea I should of made a how to dissemble thread...

 

Wow! Thanks everyone for the info. And the pics were great since I got to see what the AC evaporator looks like. I can well see how removing the cores are much easier with everything taken out from under the dash - definitely not the method I took!

And I guess the extra surface area of the AC evaporator core is one reason why they cost so much more than the heater core.

I think I will experiment with the hook-up of hoses and see what happens!

CB3

 

Then again I removed it from a bronco with the front clip and motor removed, not a fun task with all that still on the truck.

Any questions about taking it apart, just ask.