When adding freon the AC blows clod for a liitle bit before blowing it out a port in the compressor. Could this be something that is plugged.
AC releaving Press. from compressor on 2000 Chrysler Town & Country
This is due to excessive pressure build-up in the a/c refrigerant system. There may be too much refrigerant in the system, but it could be another issue. You'll need to have someone with the proper equipment check the refrigerant level and the functionality of the compressor and the rest of the system.