I donno.
  I have evacuated two systems recently, thru a gauge set, open to the
low and high sides both.  I put a side-arm flask in the vacuum line to
trap any liquid that comes thru to protect the $500 pump that I borrowed
from my school.  I have not seen any oil.

Larry A.

"G. Matthew Bulley" wrote:
>
> Evacuation removes most all of the oil. They discard the rusty old oil,
> and insert a full (pint?) fresh charge of oil.
>
> Developing business and guiding change since 1996,
>
> G. Matthew Bulley
> Bulley-Hewlett
> Marketing & Communications
> Business: www.bulley-hewlett.com
> AIM = IExplain4u
> Phone: +1.919.658.1278
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf
> Of Larry Alofs
> Sent: Monday, August 12, 2002 4:20 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: A/C Performance in '91 GL
>
> "G. Matthew Bulley" wrote:
> >
> > I've heard from two AC techs that the key to keeping your LONG-TERM AC
> > bill to a minimum, is do some SHORT TERM maintenance. That means
> > bi-annual evacuation, and replacement of the receiver/filter/dryer,
> and
> > a topping-up of the oil. Evacuation boils off ALL moisture in the
> > system, keeping the parts from rusting internally
> >
>
> I don't understand about "topping-up of the oil".  How can you tell how
> much oil is in the system.  Seems to me you would have to drain the oil
> from every component and start from scratch.
>
> Larry A.
> Chicago (Beautiful, walkable, Hyde Park)