My 240 a/c compressor is about gone so I can understand your situation. I also have a 745 that I recently rebuilt the a/c system after the compressor blew out. It required installing a new compressor, etc. My Volvo mechanic recommended using Freeze12, said that is what he had converted his personal Volvos to because it was colder than a 135 conversion. So I installed a new compressor and Freeze12 and it is very cold, cold enough to cool the wagon loaded with people on a hot Texas afternoon. So I would recommend keeping your compressor, replacing the hose and refill with Freeze12.