On my 2007 XK, from the overflow tank to the cooling system, there is a straight inline connector, under the cover, at the 10 inch distance area. The connector had broke in half. To clear the hose, I reamed it out with a series of drill bits, easily producing what seemed to be wood shavings. The piece had totally broken down. Running with no radiator pressure, had changed the fuel mix and caused a super sensitive gas pedal. Much like a dirty throttle body. The consequences could of gotten worse. I recommend people replace it.