i have a 1990 Irocz 350 and the car is all original the compressor for the ac says use 134 a refridgerant but up on the firewall where the blower motor is located it has a factory plate saying us r12 it has the original r12 lines and fittings i read that gm had a recall on the 1990 models for ac i was wondering if they refiitted the comppressor at the factory and didnt change the fittings for the service ports any help is appreciated thanks

 

Are there any R-134 retrofit stickers anywhere under the hood? Changing the fittings would require changing the lines but R-12 lines should be serviceable to a shop that has a machine thats R12 and R134-A compatible.

 

R-134a didn't come out until around 1993.

I suspect somebody converted the car by putting the new sticker on the compressor and leaving the sticker by the blower motor as is. (Probably only got one sticker in the conversion kit) Probably did a cheap drain and fill conversion and never bothered to put the new service port adapters on.

 

No need to change the lines. The new service ports screw over top of the old ones.

As far as working on the car goes, there are $30 adapters that can use R-12 screw on hoses that connect to R-134a service ports. They're handy.