[HayZee518]

older overflow tubes were made of brass and later white plastic with two "nubs" near the bottom. the rubber float whether black or red rubber had two ears with holes in them which fit over the nubs. later on they eliminated the nubs and the round portion of the flapper slid over the overflow pipe and you could adjust the flapper up or down on the overflow tube to get the best seal. check this out before you go to anymore expense with a tech or plumber. it may be just an up or down adjustment. also the float level on the ball cock may be right at the top of the overflow tube so any water leaking past might be enough to start water flow in the ballcock. adjust the float down a half inch. fluid-master is a name of a ballcock.