I am new to Orange as my brother bought a used Kubota 2015 I think. All of a sudden it started overheating after he had it for a couple years. I changed the water pump, head gasket, thermostat The sensor on the head and the one on the thermostat housing. After refilling the coolant system and letting it heat up the thermostat opened up so everything seemed fine then the next day after 1 hour of running it overheated. It has a 3 cylinder diesel. Thank in advance for any information.