Anyone know if a special coolent should be used for these trucks? I had my heater core rust out from the inside already. If the wrong coolent has been put in, what else is going to fail? Is it possible to flush it and correct the problem?

 

Had a heater problem with my 98 D 4x4 slt, flushed the coolant system out and so far it has put out more heat than before. I may have to check and replace the heater core soon though.