The Stovebolt Site Forums The Shop Area Engine Shop 216 Water Pump, T-Stat, and Other Cooling system Questions

As Jethro in Va suggested check to see if the lower rad hose is collapsing. Spent a lot of time and money working on a new engine install in my motorhome. Replaced all hoses with new, not wanting any problems. Engine was fine idling but at highway speed overheated. Checked both rad hoses at idle and both were solid and round. Finally broke down and called my 80 year old father to ask for advice. He gave the same advice as Jethro but recommended I check at high RPM. When the engine RPM was increased to highway speed (in the driveway) the lower rad hose sucked together impeding the coolant flow . Installed the spring from my old hose and overheating disappeared.