I use a bicycle pump actually. I clamp it on and pump it up. It works for me with an air chuck as well. There is a valve inside the adapter to prevent air from leaking out. The air being pumped in opens it and allows it to be filled.
Thanks Phil. Yes I guess a clamp type chuck would work, I never tried that. None of my air chucks worked since there was no pin in the center of the Topeak to open the valve in them. I had purchased it thinking I'd be able to use it at any gas station to top off the tire but, no. I've since switched to Murph's 90 degree stems.