The AC in my M9000 works on and off. It will blow very cold when I first use the tractor but after 20 minutes the compressor will turn off. The compressor does kick itself back on after a few minutes, but lately it is taking much longer to start working again. I am confident the condenser is clean as i have cleaned it over 10 times the past few days. The sight glass does have some bubbles in it. I have found that when the compressor is not working I can spray water on it and it will kick back on. Can anyone help?