Ok I have replaced commpressor,dryer,block,condenssor,it was all shot anyway.The only thing I didnt replace was the evaporator.I have charged the system and pressures are normal.Now it only lasts for 2-3 days and no freon left?It seems when system gets low or the time it leaves system I get a swhooshing/hissing sound under the dash??Could the evaporator be shot or something else?Note...NO funny smells in side the car or misst?Changing the evaporator looks like a hassle.Any help would be great thanks Gene.

 

add dye into the system then look for the leak.

 

What vehicle? If it's an LH (300M, Concorde, Intrepid) most likely you need an evaporator.