[Tim Corcoran]

Was wondering if I could get a general idea on how to remove the evaporator on my 67 Lemans. Nothing wrong with it I just want to remove it to have it serviced. Thanks.

[RedDirtRoad]

That’s a pretty big undertaking to have it removed
What are you trying to do? It’s basically a non serviceable part.

[Tim Corcoran]

I am going to have it cleaned and tested for leaks. Just trying to get an idea on the best way to remove it.

[ID67goat]

Yes a big undertaking...you need to remove the right front fender and wheel well to gain access to the evaporator housing...so yeah, remove the hood, front bumper, right fender just to get started. Then all the ac plumbing to the firewall and blower motor housing needs to be removed before you can access the evaporator housing.

Make sure system is evacuated before disconnecting everything.

[Tim Corcoran]

Thanks for the info. Since I have the engine out and plan to replace the condenser I was going to remove the evaporator and have it cleaned and tested but I changed my mind this is just too much work I will take a chance with it and hope all is well.

[455hota]

Back when I restored an AC system on my 71 Firebird, all the parts had be removed from the car. Flushed and pressure tested all the hoses and components. I think you could do the same process but with the evaporator still installed. I would
First lightly pressure test the evaporator with air. Say 5 psi. See if it hold pressure for a few days. If it does, then flush it out with the recommended solvent to clean out any AC oil residual. Make sure to blow out all the flush material. Add the recommended amount of ac oil to the evaporator and then wait for the rest of the installation.
My 71 ac system blew very cold air after I performed this process. But again my evaporator was out of the car. Good luck.


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[RedDirtRoad]

Originally Posted by 455hota

Back when I restored an AC system on my 71 Firebird, all the parts had be removed from the car. Flushed and pressure tested all the hoses and components. I think you could do the same process but with the evaporator still installed. I would
First lightly pressure test the evaporator with air. Say 5 psi. See if it hold pressure for a few days. If it does, then flush it out with the recommended solvent to clean out any AC oil residual. Make sure to blow out all the flush material. Add the recommended amount of ac oil to the evaporator and then wait for the rest of the installation.
My 71 ac system blew very cold air after I performed this process. But again my evaporator was out of the car. Good luck.


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If you pressurize the evaporator you should do so with nitrogen. Air will have moisture in it.
You should also check the oil level on the compressor sump at the drain plug. Oil should be level at the drain plug
Never add oil to the evaporator. You will oil log it and won’t get the property superheat

[lust4speed]

If the system still has some pressure and sealed up, then the nitrogen would be the best place to start, but if the system has been left open and exposed to the elements, the compressed air is probably the cleanest thing in the system for years and won't hurt a thing. Also, pressures can easily exceed 275 pounds in a working system so really no worry in hitting it with whatever the air pressure is, and the more pressure and volume, the more crap that will be dislodged and blown out.

My son's 65 2+2 has been open for a dozen years, and we will start with removing the compressor for replacement and then blowing out all the lines with compressed air. Then we'll move on to proper cleaning and flushing techniques.