There are retrofit kits to switch over to R134 but that is generally not a do-it-yourselfer project. Escaping refrigerant will freeze eyeballs and cause frostbite. Professionals wear gloves, safety glasses, and face shields.
When we first started doing this, we were told R134 needed twice the pressure to get the needed efficiency so the compressor had to be replaced, then the hoses had to be replaced with ones that had nylon inner liners because the molecules were smaller and seeped through the porous rubber easier, and the condenser had to be upgraded to handle the higher pressures. What it has boiled down to now is all you have to do is drain all of the old oil out of the system and the compressor, replace it with "PAG" oil, install adapter fittings on the high and low ports, and charge it with R134. The receiver drier should be replaced too. I did that on my '88 Grand Caravan many years ago and it worked great until it all leaked out from a leak I didn't know about.
Don't go looking for any of the "drop-in" replacements. There's one that's supposed to be environmentally friendly that uses benzene, as I recall, but that will contaminate recovery equipment if the system requires service in the future. Most shops use refrigerant identifiers now before they recover refrigerant and they will refuse to work on any car with these substitute products in them. Stick just with pure R134.
Tuesday, May 29th, 2012 AT 8:12 PM