excellent, thanks Roger and cktoy

ck -- I asked for more information because a friend and I both used the HF model on our systems a couple of years ago. we took out each of the components and flushed with acetone and compressed air, excluding the compressor. neither of us has been able to bet better than 50+?at the vent on hot days after 15 minutes of highway driving -- needless to say, that's not very efficient. best case ever was 45?, but it wasn't that hot.

additionally, I had my second vehicle retro'd at a local shop I trust. night & day difference, and the notes posted here about the importance of proper system vacuum may be exactly what's keeping me from my system running optimally.

this was always one of those things that annoyed me, having to take it to a shop to have AC work done. it was always so expensive! not to mention I HATE having people work on my stuff, but I guess it's back to being more cost effective to just have a trustworthy shop handle it.

good stuff, guys.