I usually charge the system to the pressures outlined in the Jetta/Golf
Bentley (from 85-92) as these cars used the same compressors as the Vanagon.
You charge the system until the high side reads the proper pressure for the
ambient air temp (pressure is different according to temps so you really need
a chart).  Hope this helps you.

Thanks,
Ken Wilford
Van-Again
John 3:16
http://www.vanagain.com
Office: (856)-765-1583
Fax: (856)-327-2242