Let the truck sit all night. In the morning still has pressure on the Rad. Hose. Open the overflow tank and the pressure releases and the coolant bubbles in the tank. Is this normal. I am new to diesels. Called two local dealers and one said it was normal and the other said bring it in. Can anyone clear this up for me

It's a closed system


I have never checked mine but I would assume it should hold pressure

Ttt

Actually I think the system is designed to run at 15 psi. That being said, I don't think the hose should be rock hard the next day.

Do some searches here for coolant issues I think you will find that those symptoms are usually a bad sign.

My theory is the overflow reservoir is see through so it is not necessary to open it unless it is low. I believe the cooling system is pressurized to make it more efficient. That's why the overflow reservoir is very thick see through plastic. Remember a few years ago, these reservoirs were much thinner.