My 1998/99 RR aircon is leaking its refrigerant and the problem is getting worse. Pumped up in May it lasted until August. Pumped up again it lasted two weeks. Now the normal charge of 1100 grams goes down to 300 grams overnight, so it is a pretty rapid loss.
There are two oddities about this leakage: (1) on test, the system holds vacuum perfectly. (2) the garage cannot detect any leakage anywhere in the system, either by an electronic sniffer or by an ultra-violet detector of the fluorescent stuff they mixed with the refrigerant.
The garage's only suggestion is that the fault lies in the condenser -- a common site for trouble, I gather -- and that the engine fan blows the escaping refrigerant away before the sniffer or the fluorescent detector can detect it. (But there's no fluorescent stuff thrown up on the inside of the bonnet).
Grateful for any suggestions!
Stephen