1991 Chevrolet Cavalier

I have a 91 Cavalier VL which I desire to retrofit from the existing R12 to R134a. I purchased the Quest Recharge and Retrofit kit and after installing the R-134a High-Side retrofit valve, I noticed that the R-134a Low-Side retrofit valve would not screw onto the existing R-12 fitting. Anyone know the specifics of the existing R-12 fittings used in factory installed A/C for the 91 cavalier is?

What is odd is that one of the High-Side R134a retrofit valves would fit onto the existing R-12 Low-Side port, but is way to big to attach my refill hose onto. I made quite sure that the Low-Side port is really the Low-Side port, as it is clearly labeled thusly and it is between the evaporator and the compressor.

I really would like to complete this retrofitting.
July 1, 2007.

I would check and see if there is a fitting on the accumulator for the low side it should be there. All low side fitting threads for r-12 are all the same but the side for R-12 varys. That is why most retrofit kits come with 3 different high side fitting but only one low side fitting.

Jul 4, 2007.
I am having the same problem with my 1990 Cavalier. There aren't any other valves anywhere that I can see. The low-side is clearly marked as such, the high side is on the compressor and the only fitting that will fit the refill hose won't fit on the low-side valve. Has anyone else ever run into this and found a solution?

Jul 8, 2007.