2003 Dodge Ram 2500 Heater core
 

My friend has a 2003 Dodge Ram Diesel 2500 in which the heater core keeps breaking. He has gotten it fixed 4 times by two different mechanics. One was a radiator shop and the other was the dealer. It is now leaking again. Anyone hear of these problems on this truck? Was the heater core ever recalled, bad part, bad mechanics or just bad luck?