AC Troubleshooting continued...

[Avi Meron]

Hey hey Hey , Mr. Dave..........
There is no need to replace the desiccant/RD or accumulator every time you
open the system. Just vacuum it before you charge the system, 20min is
sufficient! No need to have it on for HRS.  In doing RD (Receiver Dryer)
testing we found out that the desiccant is good for over 10years! (We only
did it on a 134A system though!).

The problem with conversions IS NOT that the 134A molecules are smaller
(although they are, by a very small amount!), the problem is the 134A charge
is TOO HIGH! For a turbo car 86 and up to 93, 27OZ is more than enough!
2 12oz cans
1 oil can with a 3 oz refrigerant used for propellant
Total of 27oz

The above figures come from about 20 to 25 conversions performed by my
esteem friend MR. Mike Rooney at Inglostat West

I hope I helped some,

You all take care now,
Avi
Go see my new web site (about alternators):  www.ultranator.com





-----Original Message-----
From: quattro-admin at audifans.com [mailto:quattro-admin at audifans.com]On
Behalf Of David Head
Sent: Thursday, June 21, 2001 11:20 AM
To: Motor Sport Visions Photography; qlist
Subject: Re: AC Troubleshooting continued...

Any time the system is completely depressurized the receiver-dryer should be
replaced. It holds a bag of dessicant that absorbs moisture from the system
as the
freon passes through. You have the possibility of the system icing up. The
system
should be evacuated and it should hold vacuum for at least an hour before
adding
the freon/oil (I prefer a couple hours). If you have to replace the
compressor,
you could consider going to 134 - but it won't cool as well in an R12
designed
system. The 134 molecule is smaller and you will have an increased
probability of
leaks - 134 capable hoses have a plastic inside lining to reduce this, older
R12
hoses don't. Also, since 134 runs at a higher pressure, all of your other
component (evap/cond/hoses) are more likely to develop leaks consistent with
their
age.

Motor Sport Visions Photography wrote:

> David Head wrote:
> >
> > Sounds to me like the compressor may be shot. Is there any pressure left
in
> > the system? Depress either side port fill and see. If so, jumper the lp
> > switch and try it - if the clutch picks up and the compressor make no
noises
> > shut it back off and get it refilled. Most likely though ugly things
will
> > happen... Alternately though you could take the belt off, put 12V to the
> > clutch and try rotating the compressor by hand.
>
> Hi Dave,
>
> Thank you for the reply. I didn't check to see if there was any pressure
> left, but that sounds like an easy check now that you reminded me.
>
> The clutch does pick up but the compressor didn't sound good. It was
> pretty rattly. However, it hasn't been the quietest for a long time (I
> think it is original and 184k miles old so if it is shot I can't
> complain).
>
> What sources do you suggest for AC parts? I assume I should replace the
> receiver/dryer (or whatever it is called) at the same time? I assume if
> there is no pressure I simple sawp the parts and take it to an AC shop
> to pull vacuum and recharge? Would this be a good time to convert to
> R-134?
>
> TIA for your help in this, you are one of the AC experts I hoped might
> chime in on this plea for help.
>
> Regards,
>
> Mike