I was taught to add feon in a system that lost some charge do to a leak, after repairing leak of course. To charge system with liquid through suction line at 10 lbs. over low side pressure. I never had a problem. I was told this is a very bad way to charge a system. Unless there is a accumulator installed and you charge through the accumulator. have i been damaging the compressors by charging liquid through suction line? I thank everyone of the mechanics who has been helping in the past. This site has baled me out many times!!!