Originally Posted by
Menel
Newbs like the OP can't erroneously use the nut, overtighten, and mess up the tube at the base of the stem, like he keeps complaining of. Dunno if that's his problem, but seen it before.
With a silica pump, smooth stem seals WAY more reliably and easier. Also removes smoother and doesn't chew the seals of the pump head.
In the OP's defense he specifically states in a later post that the failure is on the "outside" of the tube - meaning opposite of the valve or directly under/in contact with the tire.