Reply to "Air conditioning"

When 134A first was being introduced to replace R12 in or around 1993-4, the manufacturers recommended changing compressor oils, rubber hoses, reciever/driers and condensers.
In reality you don't need to change anything.
I would say that from personal experience, the York piston compressors don't like the 134A.
They don't addapt well to the higher operating pressure it creates. The Sanyo rotary compressor is what you want.
You can buy a recoditoned one for $100. The adaptor for the York base bracket is $20.
Charge the system with R134a until you get a temperature of about 50 degrees F blowing out of the registers and leave the system alone.
It is factual to say that the R12 is capable of giving you temps in the high 40's from the register.
These are the only two signifigant factors I have come across in the last ten years.
I've converted a bunch of R12 cars so there is a track record with the conversion as far as I am concerned.
FYI, I am being told that the Freeze12 is the simplest way to go. It is cheap, enviornmentally safe and is as cold as R12.
I personally haven't used it yet.
Also check out ebay for R12. A lot of people still have cases of it sitting around and performance wise it is absolutely the most effect refrigerant for automotive applications.