You may have already solved this problem, but wanted to past the information on. I also had problems with this AC and returned it to the dealer where they found nothing wrong as the system was fully charged. They then called Kubota tech service and they related that they should blow the condensor core out with air and a power washer. They did this and the AC instantly got cold in the cab. Now every so often I blow the dirt and dust and everything else that collects there and it works fine. It's hard to get to the condensor so I made a copper tube and bent the end at a 90 degree angle and attached it to my air line to blow this out. Works great. Hope this might solve your issue. /forums/images/graemlins/cool.gif