There is only one Freon, and that is R12. R12 Freon came installed in your 1991 Chevy. It may or may not have been changed over to R134 Refrigerant. If not change it over, as the cost of R12 is unbelievably high an is no longer in production.
r-12
R134a
134a
5.0 liter 170 h.p. V8. They also came with some 6 cylinder and also a 5.7L (350CID) engine
R134a
what type of antifreeze do i need to use on a 1995 chevrolet caprice
R-134 Refrigrant.
700 r 4
R134a freon.............
R12 unless it's been converted.
Depends on what type of 1991 Buick you're referring to...
It probably had R12 from the factory, this is now banned.There are "Drop in" replacements available.