It was really cold yesterday. I started up the tractor and it mad an unpleasant sound. After warming up it sounded ok but the hydraulics were not working. I let it warm up another 15 minutes and they worked fine. I did some work turned it off for 2 hours, turned it back on and hydraulics haven't worked since. There is an occasional leak around steering wheel for the last 2 years. Otherwise it's tight. I'm guessing the pump. I had the joy stick front loader hydraulic thingie replaced several years ago. The three pt doesn't move either. Is there a sure way to test the pump? What else could it be?