Contrary to what you may believe SonnyG, you may be. There was a TSB issued quite some time ago about the fill marks on the coolant reservoir. When the truck is cold, your coolant shouldn't be filled above the MIN mark, otherwise, it is considered overfilled. Hope this helps, just in case you were using those marks as a guide.I've got a problem with coolant leak. Will a pressure check detect a leak if you have a bad EGR Cooler? I took mine to the dealership and they replaced the EGR valve. They said I was over filling the reservoir. But I'm not!