From what I have seen, working in the field for 20+ years with a federal license - using anything other than R12 in a system designed for R12 will lead to problems. Converting an R12 system to 134a can be done, but it needs to be done correctly. Depending on the year of your vehicle, you may be less than satisfied with your system's performance after such a conversion.

Mitch

I'll also add-

Freeze-12, FR-12, OZ-12, HC-12, etc. are all noncompliant with ASHRAE standards, which require each different refrigerant to have a unique identifier number. Anything-12 is supposed to be R12, ONLY. This provision allows companies to use their own tradenames (Freon-12, Genetron-12, etc.) while still guaranteeing that everything-12 is exactly the same substance.

These noncompliant refrigerants are NOT R12.

Well, no, not necessarily. What leads to problems is half-baked retrofits. As you know, it's much more than a matter of sucking out the R12 and dropping in the R134a, though those "retrofit kits" on the shelf at the parts store mislead consumers into believing it's just that simple.
Right!
Huh? No. The year of the vehicle has nothing to do with it. The refrigerant -- and for that matter, every component in the system -- does not know whether it's under the hood of a '62 Lancer or an '02 Intrepid. If a retrofit is contemplated, the entire system must be looked at with an eye to spotting components that may not be efficient enough to work well with the new refrigerant. Certain condenser designs (serpentine), for instance, tend to create very high head pressure and incomplete condensation under high-demand situations, and so should be changed for more efficient parallel-flow condensers.

Mitch[/quote]

What Dan said. This is why I don't post much, on A/C questions. So many people just want to do it "down and dirty", and others post about "you don't have to do it like that", and they have no idea what they are talking about. I am a professional, and it sounds like Dan is also. I will only do it the correct way, and will advise that way also. Dan has answered this post better then I ever could.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Charlie, Dan . . . I really appreciate this info . . . don't stop. You enlighten us all.
I want to add AC to an older car . . . are you recommending to just take it into a shop and get a custom instalation or are there portions a home mechanic can do?

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Cheers!
Al T

Oh, gracious, no, there's plenty you can do by yourself. With appropriate guidance obtained e.g. here, you can select the components, and there's no reason you can't mount the actual components in the car by yourself. The part that really requires specialised knowledge and tools is the actual evacuation and charging with refrigerant once the system is all in place and ready to go.

There are a LOT of factors that go into selecting each component of the system. Some things are a given. For instance, definitely use a parallel-flow condenser, not the older serpentine or tube-and-fin type. And you'll need to upgrade your radiator and fan to cope with the added heat load. Some things are less clear-cut. There are at least four different compressors you can readily mount on a Slant-6, for instance, and each has its own benefits and drawbacks. Probably the best thing to do is to post very detailed information on your project. What exact car (year, model, 2-door, 4-door, wagon, convertible?) Which engine, what transmission, what significant modifications? Tell us about where you live -- it gets very warm and you want the car cool, or it gets blistering hot and you want the car to be like an icebox? Does original appearance of components matter to you in the car and/or under the hood? What kind of budget are you working with?

DS

the air conditioning in my 74 duster broke the other day, I replaced it with a much nicer looking unit form a 87 omni. The black nob had broken off the end of my stock unit, but now my windows go up and down nicely again.

Oh, you have one of those new type O2 systems. I hope you used the correct lubricant.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thxs Dan - I'll provide details when I'm at that stage.

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Cheers!
Al T

Though it's not the same car, the principle is the same and you can get an idea what you might run into if you install it yourself.


http://slantsix.org/articles/vintage-ai ... ge_Air.htm