Probably not. R12 was in use until the early 90's. For example, my '91 Jetta and my '92 Aerostar both had R12 when I purchased them. However, older R12 systems can be converted to R134a. Any O (to the green type) rings and the accumulator have to be changed and the system pumped down completely. Both of my cars ran very cold afterwards. The only drawback is that it tends to leak out a little every year, but that is not a problem cause you can readily buy R134a on your store shelf....
R134a
Was built for R12, should be converted to R134a
Yes a 1998 will use r134a
Was built for R12, should be converted to R134a
A 1999 Ford Mustang has r134a in the air conditioning system
Would have been built for R12, can be converted to R134a.
Will parts off 1985 mustang interchange with 1989 gt mustang?
(That would be R12 ) assuming it hasn't already been converted to use R134a
Yes, essentially all AC systems use Freon. After 1992, U.S. law required manufacturers to switch to an environmentally friendlier Freon, R134a.
Yes
Was built for R12, should be converted to R134a
Was built for R12, can be converted to R134a.