Beto Floor Pump
I just purchased a Beto Floor Pump (Dual head Presta/Schrader). I am trying to use it to inflate my mountain bike tires (presta valves), but it doesn't seem to work properly. Air is comming out of the Schrader hole - the larger opening, when I insert the presta valve in (as far as I can push it in). I have opened up the presta valve all the way (I know this as I can inflate the tube with my hand pump). Is there a switch I need to set on this pump to close the schrader valve?
My thinking is that when the prestavalve is inserted, it should automatically close the schrader hole. am I right?