I can;t get my air valve to open. It screws in fine then stops and I can still squeeze the tire and no air comes out like they show in a DuBro video on pumping them up. I suspect I am doing something wrong but can;t figure out what it would be. I can;t get the inflater piece to screw into the tire valve any further without grabbing it with a pliers or something and doubt that is a good idea.