Don't just buy any compressor just because it is new. I bought one
that was new, but not a AC Delco and it didn't last very long and was
nothing but trouble. I just had a new compressor, AC-Delco, put on
and I paid the AC shop in Las Vegas $430 for the part. I looked
around on-line for one but I couldn't find an AC Delco one new.
That's the make of compressor that was on my car when I bought it. I
don't know if it had been replaced or not, but I doubt it because the
car was mostly used in Seattle, where you don't use AC much.
I have driven though Death Valley and this week to Venice Beach and
back and the new AC setup has worked just like when the car was new.
I had them put R-12 (freon) in because that is the coolant the system
was designed to use. We tried 134a once, but it didn't cool well
enough. I replaced the evaporator and condenser last season.