jc92073

I am starting to put my car back together and need to decide what to do with the a/c. Has anyone converted their stock system to r134a? How well did it work with your system and did it last?

Thanks,

Joe

urban_cowboy

My car has been converted over and I converted an 88 Bronco several years ago. It is nice to have 134 when your system leaks a little because you can just buy replacement fridgerant at a parts store. IMO, it does not work as well. If you system works with R12 and does not leak, I would not change over!

JMD

I have never converted a Mustang A/C system, but I have converted numerous others.

Frankly it is your only real option that makes any economic sense whatsoever, IMO of course.

If the compressor is fairly modern,if it has been replaced in the last 10 years or so, it should be compatible with R-134a and ester oil. There are two refrigerant oils available for 134, avoid the Pag oil for conversions, go with the Ester.

Even if you have to replace your compressor with a more modern one it will probably be cheaper to buy a compressor and the 134a than to buy the R-12.

Also, if (when) you blow a hose or compressor in the future, you wont need to get a second mortgage to refill the system.

jc92073

Well, that is what I am afraid of, I have the original compressor. I have converted newer systems, but I don't know how/if that old compressor will hold up.

JMD

If you shop arround, I imagine you should be able to get a new stock style compressor for around $150... ??

urban_cowboy

There are numerous places that are selling parts and pieces for a/c convertions. Vintage Air is one that comes to mind, but there are many others. Not sure if you can get just the compressor, but would be worth a shot. I have found various parts I needed from them in the past.

mustdoc

I made the switch to a new Sanden A/C compressor (and additional parts) for several reasons:

The new compressor is more efficient.

It weighs less.

It uses R134a (whose molecules are larger and less likely to leak not to mention it does not destroy the upper ozone layer making it more environmentally friendly - BTW I have been told that the ozone layer destruction is reversing.).

R134a is cheaper and more readily available than the old refrigerant.

I cannot think of a good reason, economic or otherwise, to not make the switch unless you are looking for an original Concours restoration.

BTW, the recent Mustang Monthly has a good article on this very topic. I suggest you check it out! It has many helpful things to consider besides just the compressor (i.e. the dryer should also be changed according to this article).

urban_cowboy

The big reason not to switch is R134 is it does not work near as well in a switch over as R12 did. I am not sure if it is because R134 requires higher pressures which the old systems do not handle well or what. I just know my Bronco A/C is at about 75% of what it used to be with R12. That is based on cold air temps. Neither my mustang nor my Bronco cool as well with R134, but as said above, it is convenient when you need to add some fridgerant and is much cheaper. R134 seams to work better when the condensor and evaporator coils were designed for 134 (i.e. cars since 96 or so). Maybe a forklift upgrade would work better than what I did.

jc92073

Thanks for all the replies. I will probably just order a Sanden compressor. Just wondering if anyone got 134a to work with the old york or tecumseh.

JMD

The Yorks are still available brand new, the new ones work with 134 no prob. These compressors were used on heavy trucks until just a few years ago, they are plentifully and cheap if you are willing to shop a little.

If a person were to change the expansion valve or orifice, whichever is used in the old Stangs, the efficiency of the 134 will be improved.