I had thought that the 5030 might have taken water in through the cab top vents for it to drip from the interior vents after it is started up. It has been having the odd drip from it for a few months now. But now I'm considering that it might be a leak on one of the heater pipes that come into the cab. There's little taps on these, can they be turned off and the tractor run safely with them off? They are never used. Radiator dropped 2 inches of water in 48 hours last week. Filled it on Friday and back to it yesterday and it was still full. Put back on the cap, ran it for 5 mins just ticking over, not warming it up at all. When it stopped, there was a good trickle of coolant from the little overflow pipe from the top of the radiator. It didn't lose any from here on Friday, but lost it yesterday after I removed and put back on the radiator cap. Could it be the cap that's causing the problem? It seems to be working fine and not over heating even after a good hard drive.