Boy I have a lot of questions these days. I'm getting ready to hook up the AC and I was trying to blow a little compressed air through the evaporator to see if it was clear. Very little air came through although some did. Does it sound like the evaporator may be clogged?

Thanks.

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Sweet Emotion

Is it possible you were trying to blow air through the evaporator with the expansion valve in place? The expansion valve lives at the inlet of the evaporator, and it is sort of the "carburetor" of the A/C system. Its job is to provide a restriction to the refrigerant so that it sprays into the evaporator at very high pressure and very low volume. It is very difficult to blow air through it (and is a prime cause, as it gets older, of poor A/C performance -- consider installing a new one).

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Actually the expansion valve is removed and I was putting air right into the evaporator. I also have the little elbow removed as well. I have a brand new expansion valve on the bench along with all the hoses (newly rebuilt) and drier/filter cannister. Is there any restriction in the evaporator itself? If not can I clean it somehow or am I looking at replacing it? BTW I also have a new condensor and all new orings and seals as well. I would like to get it all together here shortly but I want to make sure the evaporator is good.

Thanks.

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Sweet Emotion

Well, the evaporator is basically a long length of metal tubing coiled up and arranged in a serpentine fashion. So no, there should not be any restriction greater than there would be from, say, a 10-foot length of tubing of the same diameter. If you find such restriction, there's something the matter. You can try reverse-flushing the evaporator; it may or may not clear it out. If you can't clear the clog, you'll need a replacement.

Hope you got a manifold-type (parallel-flow) condenser!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Well I don't know waht you mean by manifold type condenser. I got one that looks exactly like the original. I'm sticking with R12 if that matters. I went to the AC shop at lunch to get a gasket I needed, and the owner/technician told me to just hook it all together and he would check it all out for me. He did the rebuild on the hoses and sold me all the other parts. So tonight I'm gonna oil up all the o-ring joints and o-rings and assemble it. I also asked him if I needed a new valve in the compressor and he looked at it and said sometimes they go bad but there is no way to tell until it's hooked up so he suggested using the old one. I also explained the evaporator issue and he didn't think there was a problem but he said he would check it out.

My son will take it in tomorrow and I'll post the results.

Thanks.

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Sweet Emotion

I've written about them a lot in this forum. It is worth the very slight extra cost (and, now, slight delay in your project's completion) to get a manifold-type (parallel-flow) condenser. They are much more efficient at condensing refrigerant and much less restrictive. This translates to lower head pressures, which means much less load on the engine when the A/C is on. Better performance, better mileage and better car cooling, win/win/win. See Here.

The old-type condensers are "good enough" for R12; parallel-flow ones are much better with any refrigerant (and will allow your A/C system to keep blowing nice 'n' cold if you ever retrofit to R134a in the future).

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Maybe I'm missing something, but I don't see anyone wouldn't convert to R-134a at this point. Especially if the system is empty, it would more than pay for itself simply during the initial fill. (Unless prices are significantly different in AZ than in MO)

Edit: I'm not trying to be-little or offend anyone, I'm just curious as to his reasoning.

Actually I gave it a lot of thought and a shop told me that R134 has gone up in price significantly in the last few months making it alomost a wash. Well I believed him and went ahead and got the condensor and expansion valve for R12. But when I looked at the R134 cans at the auto parts store they were still pretty cheap. But I fell commited at this point. If holds for a few years I may consider R134 down the road. I was told R12 is about 40 to 50 a pound.

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Sweet Emotion

R12 is not $40 to $50 a pound -- check eBay.

The point I was trying to make is that the "R134a type" condenser is more efficient with *any* refrigerant, including R12.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

How much is R12 and R134? Also with parts in car and ready to go all I need is evacuate and charge. Unless I get a 2X4 upside the head I'm going R12.

I'll duck now.

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Sweet Emotion

Prices vary widely on refrigerants. R12 moves more heat than R134a (easier to get nice cold air) but R134a is the direction the industry has gone (easier to get A/C service).

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Buying new, in limited quantity, from a local supplier, you will pay between $40 and $50 dollars for a can of R12, compared to $8 to $11 for a similarly sized can of R134a. (This is in the mid-Missouri market. I'm not sure how regional these prices are.) Now, if you can get your installer to purchase freon off E-Bay (and sell it to you for that price), that seems to change things dramatically. Just keep in mind that you, as an individual, can't purchase R12 directly like you can R134a.

As far as stop-leak, and such things, I know the stuff we stock at work is /only/ for R134a, and claims to not be compatible with R12. Now, I'm sure that you can get such things for R12, but I know it's less available. (and could easily run you a little bit higher cost) While that probably isn't a concern at the moment, it is something to keep in mind five or ten years down the road when you get one of those "charge it once a year" leaks somwhere in the system. Also, if you choose to just charge it and not use a sealer in that situation, keep in mind w/ 134, you can do it yourself for about $20. I'm assuming that the technician you're using charges something like that just to hook up his gauges.

Can so, you just need a license.

And the license is completely pathetically easy to get. Just surf over to IMACA, spend $15 and 15 minutes on the open-note test, and your license arrives in the mail in about a week.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

And as soon as you buy R12 without having the proper recovery equipment you can be fined for thousands of dollars. (and recovery equipment isn't cheap either)

20+ years ago when you could buy R12 for under $1.....................

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes