I recently bought a 300E for my daughter. The AC needs to be recharged. I have all the maintenance documentation and it indicates that the system was retrofit to 134A two years ago. However, The adapters are still the R12 fittings. Now I am confused. The system is now empty. I ran a vacuum for 24 hours. Found no leaks. Since the PO may have been charged for a conversion that was never done, I wonder what is (was) in the system. My thought is to pull the compressor , drain and replace oil with ester, vacuum and charge with 134A. Should I flush and with what? I would like to know what other thoughts are on my dillema. I have all the guages, etc. John