Ever since I did the head studs/Gaskets and EGR delete my low coolant message pops up everytime i turn the truck on. It never did this before i pulled the cab and did the work so I am at a loss as to what is causing this. I have checked all the grounds and connections and it all seems to be fine. Could the coolant tank sensor have gone bad while the tank was out? What else could be causing this? And yes, the resevior is full. There is a very small leak where the lower coolant hose goes into the radiator but that is becasue of this dumb ass quick disconnect design and i pinched the internal o-ring causing the leak. I doubt that could be causing the light to come on but who knows.