I just drained the engine coolant, back-flushed the system, and added the new coolant on my "new to me" used 2001 Windstar (3.8L engine). I could not locate the radiator cap. I noticed the reservoir pressure warning labels so I assumed the radiator was born without a cap. Something new to me. The Haynes manual instructions suggested there's a cap somewhere. How can I be sure the air is completely out of the entire coolant system?
Thanks!