leaking A/C evaporator

[Tom L.]

A couple of weeks ago I found that the evaporator on my '72 was leaking. I was able to find a supplier in California, not exclusively corvette, that had one. I ordered it and when it arrived I was not amused. It was still wet with silver paint, the plastic wrap was covered in water (probably why the paint didn't dry), one tube was not sealed (water and A/C systems do NOT get along), the mounting tabs were not straight and worse of all the suction tube was not properly aligned.

After seeing it I see that they just buy cores and solder or weld the connections for each application, I'm Ok with that. I'm almost suprided that they're even availible. The real problem is that the suction tube is so out of alignment that the POA valve will be positioned incorrectly and won't strap the the factory mounts. The piece is goung back for sure. I'll post pics when I take them.


So here's my questions, the leak is on a seem on the bottom of the evaporator, has anyone ever had one successfully welded closed? Also, how does anyone feel about buying a used avaporator? Do they often leak?

It's so much work to replace the darn thing I'd like to only do it once. Thanks!!

[Dick W.]

Re: leakingA/C evaporator

Probably not much luck welding a 40+ year old evaporator. The refrigerant has oil in it and the aluminum is somewhat corroded. It does not make for success.

[Monte M.]

Re: leakingA/C evaporator

Tom,
I would not be worried about the age as much as the corrosion. As you know, I have done a few of these A/C systems. As few as ten years ago I used evaporators out of cars that no longer had a need for them.
BUT, the key is to find one that has had the openings plugged. If they are plugged, the oils will keep it in pretty good shape.
Take one of those flexible grabbers. The kind you push on the end and the prongs open on the other end.
Put a small cotton ball in the end with the prongs and slide it in a ways to see how dirty it is. If it is just dirty oil, and the rest of it looks good, pressure test it and go for it.
Then of course flush it out as you did your other parts.
If anything other than oil comes out, do NOT take the chance.
Best of luck,
Monte

[Tom L.]

Re: leakingA/C evaporator

Monte, any experience with repro evaps? I'd like to hope that there is at least a reasonable repro out there.

[Monte M.]

Re: leakingA/C evaporator

Tom,
The only new evap I ever used was an NOS one. It was a nightmare because the bottom tube was attached at the wrong angle. We had it fixed and it worked just fine, but it sure was a pain.
Other than that, they were all used. I think you might be surprised how many might be out there that have been closed off after disassembly or removal of other A/C parts.
I will ask a buddy of mine if he has one that is in good condition, but it is a long shot these days.

Monte

[Monte M.]

Re: leakingA/C evaporator

Tom,
Did you look at this one.
It seems to look like the real deal.
Just a guess.

http://www.ebay.com/itm/Evaporator-GM-Chevrolet-Corvette-1969-1972-10-6188-/190710245357?pt=Motors_Car_Truck_Parts_Accessories&hash=item2c673767ed

[Joe R.]

Re: leakingA/C evaporator

Tom,

Have purchased from Old Air Products in Dallas before. Great company and stands behind their products 100%. You may purchase with confidence from them.

JR

[Tom L.]

Re: leakingA/C evaporator

The old air piece is what I should have gotten but I was frustrated and ordered from the first place that had one. A mistake but I'll deal. Thought I'd post a couple of pics of what they sent, one of the original and one of the repro with the POA valve on it. Pretty sad.

[Monte M.]

Re: leakingA/C evaporator

Tom,
That is why everything has gotten so much better over the past couple of years. The Old Air Evaporator has all the correct hook-ups. Until a few years ago you had to find a good used one if you wanted it to look the same.

The one draw back to a hobby like this is: it is very difficult to stay up with what is being reproduced. Until recently you could get a replacement evaporator. Replacement, being the key word. They did not look the same, but they would work.

Now, you can actually get one that works and looks the same. You have to sift through parts to make sure of what you are getting.

A lot of people are still selling the replacement parts that work, but do not look the same.
Bottom line is: you have to double check before you buy anything. New or used.

I am glad you finally found a good reproduction that looks and works the same.

Monte

[Tom L.]

Re: leakingA/C evaporator

OK, so I contacted the vendor and they took it back with no problems. I was a little concerned that there would be an issue.I took my original to a buddy that has an a/c shop and he tried to fix it. The oil was not a problem, the old metal was. Each time he heated the metal to solder it he sealed the leak but the metal next to it became porous. Something I'm familiar with after years of repairing old copper evaporators. I did find an NOS part at a reasonable price but I'm now concerned about the age of the metal. Any thoughts? Is it worth buying the NOS piece for a bit more $$ knowing it will fit but have no one to go back to or is a repro a better route since it's new and I'll at least be able to call Old air or Classic auto air (they both make one that look the same).

[Dick W.]

Re: leakingA/C evaporator

OK, so I contacted the vendor and they took it back with no problems. I was a little concerned that there would be an issue.I took my original to a buddy that has an a/c shop and he tried to fix it. The oil was not a problem, the old metal was. Each time he heated the metal to solder it he sealed the leak but the metal next to it became porous. Something I'm familiar with after years of repairing old copper evaporators. I did find an NOS part at a reasonable price but I'm now concerned about the age of the metal. Any thoughts? Is it worth buying the NOS piece for a bit more $$ knowing it will fit but have no one to go back to or is a repro a better route since it's new and I'll at least be able to call Old air or Classic auto air (they both make one that look the same).

Oil contaminates the metal combined with the corrosion due to age make repairs almost impossible

[Tom L.]

Re: leakingA/C evaporator

I gave the repair a try and failed, always worth a try.

Any opinions on aging metal and pitting on an NOS piece vs. a "well made" repro with all new metal?

[Dick W.]

Re: leakingA/C evaporator

I gave the repair a try and failed, always worth a try.

Any opinions on aging metal and pitting on an NOS piece vs. a "well made" repro with all new metal?

I do not think that a NOS piece, if properly stored over the years, would give any problems for many years to come.

[Monte M.]

Re: leakingA/C evaporator

Remembering the metelergy classes way back when, Dick hit it right on the head. My "opinion" is the NOS should be just fine. Take a look and make sure the outside shows no signs of aging and I would assume the inside would be good as well.

Monte

[Tom L.]

Re: leakingA/C evaporator

Well, I wimped out on the NOS piece and ordered one from Old Air. After my last experience I couldn't buy something I know no history of since I don't know if it was really stored properly. I simply feel better knowing I have recourse. The NOS was a "buy it, you own it" thing. When the new one arrives and I get a chance to inspect it I'll report back. I'm sure I'm not the only one out there that might need an evap, current info is good. Thanks to all!