Q: I have a 2008 f250 with a 6.4 diesel. I have the updated hoses on it. I moved the top hose at the radiator and I heard pressure re

Your best indication of the efficiency, and condition, of the cooling system is the engine operating temperature. If the operating temperature is in the "normal" range for your engine, then you need not worry. As far as the generation of air bubbles, if your cooling system is equipped with a pressure relief cap on the radiator, you might want to test the cap to be sure it is sealing properly. Such caps are designed to open at a set PSI and also provide vacuum relief when the engine is cool to re-admit coolant to the radiator from the overflow tank. If you desire testing of the cap and a further evaluation of your cooling system please request a service appointment and the responding certified mechanic will resolve this. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.