I have said to replace the condensor to a new style when converting to 134a before, but I believe that primarily applies to people in the hotter parts of the country, like here in Phoenix or Vegas, or desert areas, whatever. In the not so hot climates I'm sure the old R-12 condensors probably work good, but here in Phoenix, they just don't cool the freon down as well in the extreme heat and therefore, they don't cool the interior as well.
It DOES work fine while driving down the highway, at constant higher speeds, but in city traffic, it just turns into a swam cooler at best and overheats the compressor, which shortenes it's life.
The '94 I have is setup from the factory with everything needed for the 134a and it stays cool all the time, even while idling, same with this '05 Avy I've been driving for the past several months, but when I had the old style "R-12" condensor in the Burb, it would not cool while idling very well.
I did buy a new condensor designed for the 134a freon and installed it in the Burb a few years back, but the compressor decided to spring a seal leak while filling it up, so I gave up on it till adequate money is available for a brand new one.
The new condensor only ran me about $125 or so, I personally don't think that's too much to toss at it for a much better working AC system.
just my opinion.
