On my last coolant change I used an Airlift to create a vacuum on the system. In the past I have "burped" it by removing the hose at the cylinder head but I don't like doing it. The Airlift worked great at pulling the new coolant in but it appeared that it left an air pocket near the radiator. After a couple tries I got it out with the help from an Ultragauge to monitor water temperature. I think this will go smoother next time after I learn a few tricks.