I have a topeak mini master-blaster hand pump, that works with both schrader and presta valves. It took me a while to figure out that I had to flip a little rubber piece in the pump to make it work with the presta valves, but I am still having issues. It doesn't seem to want to lock on to the valves securely, and whenever I try to pump up the tires I seem to end up losing more air than I am pumping. Does anyone know how to make this work?
Thanks in advance.