Coolant in water seperator filter

Couple days ago I brought a truck in for a service and as I went through my service process I came to the water separator. I cleaned the plastic piece on the bottom so I could see the fuel it was completely red. So I called over my boss and he told me it's a common problem in the new cummins motors and it's probably a bad head which is covered under warranty. I learned to pay attention to see through plastic

Hours 130