Be forewarned that overfilling the a/c can have significant economic
consequences. Bill told a tale of woe -- a busted up compressor. Apparently
the newer a/c systems, or at least the one on the 5000 are more sensitive
to overfilling than the older systems. It is certainly true that the audi
system capacity is much smaller than the older systems, about 38 ounces
compared to 50+ for big american cars of the early 80s. Bill also noted
that in his case, the original problem was not low freon at all, but
rather a bad thermostat setting (as I understood it, the switch that shuts
the compressor down when the evaporator gets too close to 32F).
It would seem that delicacy in overfilling is the reason Bentley says not
to evacuate and not to top up.
86 5000S - the maximum vw (guess the turbos are the penultimate)