There should be a spec label on the radiator support with the info. I'm thinking that since it is an '86 it should be R-12 unless it has been converted. If converted there should be a label denoting such conversion, plus the fittings will be different (however, some home done conversions are missing the label).
Hopefully someone well versed in the Euro's will step in.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.