We just had our bathrooms remodeled and had hour contractor install New American Standard toilets in both rooms. Big mistake. Both of these toilets run constantly. Seems that the flapper doesn't make a tight seal once the water has emptied from the tank. I've applied petroleum jelly to the bottom of the flapper in hopes that the jelly would help the flapper seal. Doesn't work either. Any suggestions out there? P.S. This is a new type of flapper to me. It's just a rubber flat piece that is lowered down over the water tank pipe by chain and is appox. 2 1/2- 3" in diameter.