How to Determine if your Audi is Actually Short of Refrigerant

[Mark R]

On some Audis, there is NO low pressure port.  My '00 S4 has none.  Audi
does have a procedure for filling (it involves total evacuation and filling
with a measured weight of refrigerant) it.  I don't know if the 100 is one
of those cars, however (I'm on my boat and don't have access to Alldata or a
Bentley).

Why not add a low pressure port?  IDK.  German "engineering" I suppose.

Anyhow, off-the-top-of my-head, you're running low if the high side is only
150 PSI.  If you need the procedure, drop me a note on Monday.

Mark Rosenkrantz