I'm a retired engineer and EPA certified Tech II & III , my question pertains to, recovering & reclaiming freon from ac units. Has it changed with the newer freons that are used today? Please refresh my memory on the steps to recover and reclaim freons pertaining to the EPA rules and regulations. Ive been away from the trade since the early 90s. If you will, please give me the steps to pumpiing freon back to the condenser.

Thank You
Retired tech.