Many bike shops carry a Hayes small parts kit. It will have the plug.
Yes, that plug is the bane of the Hayes 9s. A piece of tape over the plug should hold it in (once replaced).reptilezs said:anyone know of a cheap replacement for the res plug on the hayes 9 levers? the hayes mag plug is so much better with the screw and o ring. got a set of hayes 9 with missing plugs. fluid bubbles out of the bleed port when the lever is engaged. im thinking of shoving a nail in there.