I'm getting to the place where I need to re-install the AC suitcase to the firewall of my '72 442 convertible. I really want to do this right so I won't have to do it again in the future. I'm also converting to R134a. If the evaporator pressure tests OK, is it better to reuse this 46 year-old part or should I install a new one? I'm looking for good advice based on real-world experience. I'm willing to spend the money for a new evaporator, but sometimes the repop/replacement parts are not as good as original OEM. If I need to replace, who sells the best part?

I don't want to make a wrong move here! Thanks in advance for your comments.

Rodney

 

The evap's life isn't all that bad, and the external pipes are pretty stout. As long as it checks out and there aren't physical stress signs then I'd say stick with it. I've cleaned and reused a couple now. I have not had a replacement unit in my hands though.

 

I can't comment on the quality of currently produced evaporators. And I've changed many leaking evaporators in my life for other people. But on the other hand, I've got a '55 Olds, a '65 Olds, and a '76 F-250; all of which have the same evaporators they had when they were new. Perhaps I'm only muddying the water as far as making a decision. Best wishes.

 

Ive gone through literally hundreds of gm 68-72 abody evaporators. Ive some that look brand new and they would still leak. They corrode from the inside out. Ive had them not leak at 150psi of compressed air, then go to 250-300ps1 of nitrogen and then some have sprung a leak. The best indication of a bad evap has been the color of the oil that comes out. Typically the more brown it looks the worse feeling it get that it will leak. That's why I always flush first before leak checking. On a side note, CdRod, did you get the the messages I sent you? For some reason, my message box shows nothing sent.

 

Banny:
The AC system in my car has been open for many years. It sounds like I should plan to replace the evaporator. Is there a brand or seller you would recommend? Also, I've seen one vendor advertising a parallel-flow or multi-flow replacement to get the most from the 134a conversion. Is there any benefit to this replacement?

 

Can you show a link to that vendor? I would say look for a vendor who still has Delphi evaps. Those are made here in the US. There are some vendors selling china evap.

 

This is the parallel-flow evaporator I mentioned. Not sure where it's made, but it's sold by ClassicAutoAir.

 

FWIW, *all* evaporators are parallel flow. Don't pay extra for that.



The old condensers were tube and fin, while new-style condensers are parallel flow (and better with 134a). There's one direct fit parallel flow condenser floating around out there which I would highly recommend over adapting a generic model (which I painfully, and expensively, did).

 

Oddball:
I thought the same thing. Their description is misleading, it's really a "multi-pass" evaporator, 3-pass if you go by the diagram in their ebay listing. They claim "the parallel flow evaporator forces the refrigerant to flow back and forth through a series of passages multiple times before exiting. This means the refrigerant has multiple chances to absorb more heat from the air flowing through it. It also keeps the entire evaporator cold for maximum cooling the refrigerant"

Here's a pic from the ebay listing:

 

Unless they are using a stock photo and is not their actual evaporator, that looks like every other Chinese evap ive run across. But in regards to their claim, I would ask to see an evaporator that has been cut open to verify. Otherwise I don't believe it.

 

If it were me and I was buying a new one Id go for this one as its made in The US and the tanks are the exact size as the original Harrison evaps. If you look closely you will notice that the tanks on the CAA evap are shorter. https://www.oldairproducts.com/produ...aporator-coil-

And if you want to save some money and go Chinese then the Parts Place has what looks to be that exact same evap as CAA for around $55 cheaper. and free shipping. https://www.ebay.com/itm/1968-72-Cut...UAAOSw9GhYdAAS
CAA charges shipping. The Parts Place has it even cheaper on their website but you probably have to pay shipping there. https://www.thepartsplaceinc.com/old...ID=4&year=1970

 

Banny:
Thanks for the evaporator part recommendation. This is exactly the info I was looking for when I started my thread. There is soooo much Chinesium crap out these days, you really have to do your homework up front so you don't make a bad purchase. I will call Old Air tomorrow to order a new evap unit.

Rodney