2000 Sillhouette AC Issues

I just bought a 2000 Sillhouette and the AC issues have been non stop. First rear ac was warm. A crimped expansion tube was the culprit. Then the front ac gets warm... first the left side then right then the back I am assuming because the freon was slowly leaking. They replaced the bottom side port 3 times then dye tested everything then said that the compressor was the only thing they could see leaking. replaced the compressor... same thing... works for a day then the front gets warm, again, starting from the drivers side then the passenger then the back. Any suggestions?

Are you charging it with the rear AC fan off? On my 2000 the pressures were reading to high if I checked it with the rear on and I wasn't getting enough freon in it.