Proper charging of an automotive AC system, (or most AC systems) is done by
weight. System pressures are then the result of proper operation and
external conditions. When using r-134A proper fill is approximately 85% of
the fill for R-12. As R-134A is azeotropic, (I think I got that right) it is
a poor practice to top leaky systems off. If it needs more than 10% you
should fully evacuate and recharge.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Ken Wilford
Sent: Tuesday, June 15, 2010 10:25 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Need AC chart expected measurements...

Steven, I use the AC chart from any other VW Bentley from the 80s or
early 90s.  They all have them except for the Vanagon.  On the low side
you want to see between 35-40 psi wen fully charged.  The high side goes
up to around 250 psi, maybe higher when fully charged but I usually just
pay attention to the low side unless the system is fully charged and
still not working properly.  Also the low side metal pipe coming out of
the compressor will start to get cold and stay cold when the system is
about full.  I have been servicing these systems for many years and if
you follow these guidelines you should be able to charge a normal
system.  If you have any other questions please feel free to pmail me.

Ken Wilford
John 3:16
www.vanagain.com

Steven Johnson wrote:
> Hi folks,
>
> I'm using a manifold gauge set on my '91 Campers AC system and cannot find
> anything in the Bentley that shows what pressure to expect (high or low
> side)
> at given ambient temps.   Is there such a fact sheet or spec.?
>
> Thanks,
>
> Steven
>
>

--
Thanks,
Ken Wilford
John 3:16
www.vanagain.com
Phone: 856-327-4936
Fax: 856-327-2242