"Woody" <TheDuck@pond.net> wrote in message
news:24Meg.88192$H71.62918@newssvr13.news.prodigy. com...
> It is a lot easier to determine the charge today than in R-12 days. All
> you need is the $20 gauge which he has. Connect it on the low pressure
> line and look at the gauge. It has a blue area around 40 psi. If the
> needle is in the blue area with the compressor running the charge is ok
> and you need to look elsewhere. Taking it to a garage is not a finite fix
> as most know very little about the system and will add many items that
> aren't broken. If you take it to a garage to be fixed make sure it is one
> that specializes in air conditioning. As for the initiator of this forum
> he needs to find an AC specialist because he does not understand the ac
> system and hasn't taken the time to learn the skills needed to do what he
> is trying.
>
I disagree with the part about it being a DIY job by anybody but a trained
reefer man. I never had any trouble with R-12 and could fill by guages,
sight guage or "by ear." When we tried filling my son's Integra with the
bottle and guage the guage never came near the blue zone, even though the
outside temperature was mild, we spent about half an hour to allow the
system to stabilize, and we went through the proper fill somewhere in that
time. We ended up with the system overcharged and we could here the
compressor complain as liquid hit it - a sure sign of serious overcharge -
so I told him to keep it off until a professional could fix it. Running it
that way can "slug" the compressor, damaging of destroying it. I had been
told many times that R-134a can only be properly charged by evacuating and
adding a measured amount of refrigerant, and now I believe it. BTW - a
single guage was never adequate for R-12, either. The high side and low side
pressures were important for getting in the ballpark, and only a measurement
of the temperature of the suction line combined with a measurement of the
low side pressure (a measure of the superheat) gave a true indication of the
charge.

I do certainly agree that taking it to a pro is probably the cheapest way in
this situation. I was chagrined to find that regulations and the difficulty
of working with R-134a have driven most garages
out of the refrigeration business.

Mike