How do you know it is full of Freon ?(FYI Freon is a registered trade name of Dupont, the refrigerant your system uses is R134a). Your system takes 21-23oz of 134a refrigerant and 5.5oz of refrigerant oil. The only way to make sure that the system is full is to purge all the refrigerant and add in the exact amount 22oz in. You should never purge refrigerant to the atmosphere it should be recovered by a recovery machine. Once the proper amount of R134a is in the system, then you can put the gauges on it and verify the pressures and temperatures are correct.