Gator 6x4 with yanmar 3cyl diesel. It overheats and I found no coolant in it with alot of rust. So I replaced water pump, tested thermostat to be fine. And replaced fan temp switch that was malfunctioning. Now this thing is still overheating. Coolant is filled and bled and circulating properly, fan turns on as it should but eventually it still over heats. And my coolant isn't leaking externally and the level is staying where it's supposed to.