No, you probably did not use the white plastic elbow fitting that came with the fill valve and the tube is inserted too far down the overflow pipe. Pull it up and secure it or fnd the elbow fitting and use it.: My toilet runs on and off and I have replaced the flapper with the red one and lightly sanded around the flush valve flapper hole. It is not going over the flush valve but I was wondering if the flush valve rubber gasket could rot and leak. ANY SUGGESTIONS????