Q – My 1991 Carrera AC no longer blows cold air and I wonder about converting it to the newer R-134 Freon. I had it charged three years ago and it worked pretty good for a couple years What do you recommend? Mike
A – Before you take that step, it should be diagnosed. One cannot assume that it needs to be converted just because it does not cool. And besides, the Freon itself is usually not the problem; it’s the leak, the switch, the hose, the relay etc. If the system worked fine three years ago and continued to work afterward, maybe you just need a charge?
Does it have any Freon in it right now? Does the compressor run? If it has some pressure and the system operates, a recharge and leak test is the first thing to do. Then you develop a strategy.
If you are considering a conversion, there are a number of considerations. It is common knowledge that the newer R-134 Freon is less efficient. And to change it over involves some component replacement. There were concerns about the supply and cost of R-12, and yes, pound for pound, it is outrageous. On your car, it doesn’t take too much to fill the system. So considering the quantity that it takes for a charge every couple years, is “the cure worse than the disease”? – MC