Just wondering how many have a rock hard upper hose and how long have you have it? I've had it for as long as I can remember and a low coolant light everynow and then. I've put a new cap on the overflow tank. If there was water in my oil would I be able to see it pretty easily? I just drained alittle bit maybe 2 ounces of oil and I can't see any coolant in it, it should have settled to the bottom overnight. But my oil is jet black also. I am going to leave the cap alittle loose today to keep it from building pressure, because I think it maybe blowing out overnight?? Because I see alittle puddle of coolant on the street over the last week. My truck doesn't white smoke, dont feel like it has a loss of power etc. These hoses being hard seem to be a very common issue, and I'm not sure they all can be head gasket problems like everyones mind jumps too.