Originally Posted by Taylorgso
Steve: If you have the yellow Air-Flexx extenders - which I have - the problem is the inner core doesn't extend far enough out for the pressure gauge to engage it The solution for me was to remove the extender and using a utility knife, cut off the outer end one thread at a time until the pressure gauge will engage the inner core. Cut off just enough so the inner core is even with the outer tube. I had to remove two thead widths to get a reading. You can take a mill file and smooth the end down afterwards. If you have to take off too many threads, you may have to get a thread chaser (available at any Advance store) and turn down a few extra thread widths in order for the tire pressure monitor to go down far enough, or for the valve cap to engage tightly.
here is a simple fix that does not require you to remove and cut the extenders: take any round, solid rod (plastic, wood or metal) that is 3/16 inch in diameter and cut a 2mm piece off it. put a bit of silicone grease on it and insert it into the valve stem. I used a 3/16 screw. the silicone grease helps prevent the piece from falling out when the valve cap is opened.
works like a charm.