I'm about to do the same, but I need some more clarification:

1:  Where is the expansion valve, and where do I purchase one?  I didn't
see it on our friendly internet vendors' sites.
2:  I can see one of the ports on the line near the compressor.  Where is
the other one?
3:  Shouldn't you replace the ports before you evacuate the system?  :-)
4:  I have never heard of flushing with non-chlorinated brake cleaner.  Do
you just spray it in each section of plumbing, followed by the air?

Thanks,
Michael Townsend

----------
> From: Mark & Laura Magee <marklaura@HOUSTON.RR.COM>
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: AC Conversion: R12 to R134A
> Date: Monday, July 23, 2001 5:10 PM
>
> Remove your compressor, drain mineral oil, flush compressor and lines
> w/non clorinated brake cleaner using an air compressor and blow tip to
> remove old oil/junk.
> Fill compressor w/PAG oil.
> Install new expansion valve.
> Install new filter dryer.
> Close all lines.
> Vac system.
> Install new R 134a ports.
> Charge to around 40 PSI on low side: 80% of R-12 charge. Sight glass may
> still show bubbles.
> Cold air blows and your done.