I have a new 2010 Georgetown 379TS and I feel stupid because I cannot add air to one of my rear inside tires. It has a valve extender and I have NO problem checking the air pressure but I cannot add ANY air. Any advice would be greatly appreciated.
Are you able to get a pressure reading from the valve extension? If not the extension is not pressing the original valve pin in on the rim. Try tightening the extension and check to see if you get a reading. You may have to back the valve pin out some from the valve on the rim in order for the valve pin to be depressed.