Are you trying to fill the system with a dyi refill system? If so there should be a gage on the bottle. Make sure you're not trying to overfill the system. If the Schrader valve is bad the gage won't read anything.
Hope this helps.
Has system been evacuated? Bad inlet valve, seems to be.
is compressor clutch kicking in?
You shouldn't be using Freon. It's currently a semi-banned substance in the US due to environmental concerns. You should be using a replacement like 410A or ISCEON.
