Sounds like it's your flapper. It could be worn or dirty. The flapper is the piece of rubber at the bottom of the tank the lifts up when you flush. First I would try to clean the underside real well and make sure it seats properly when closed. If not I would go to Home Depot or ***** and buy a replacement for a couple of dollars. Just my 2 cents

Mike

MAUREEN - hi, Hammerman offered one possibility and here's another - the float is sticking and not rising high enough to cutt off the water flow. Either way - you need to remove the top of the tank, flush the toilet, and observe if the tank fills back up properly.

If it doesn't fill up properly, you should be able to see the flapper and see if it's not seating properly. Maybe the chain attached to the handle is getting in the way, or not allowing the flapper to seal properly? Or, if the tank does fill and then keeps flowing, the float's switch either has dirt in it that prevents it from cutting off, or the float's otherwise not returning to the water flow cutoff level.

As Hammerhead suggested, you can go to one of the home improvement stores (or even Wal-Mart) and buy replacement parts cheaply enough. Fluidmaster makes a standard replacement kit that includes flapper, float mechanism, and chain - it normally runs under $10 - and if you can use small hand tools, you can do it yourself in under 30 minutes. I hope this helps some - regards and good luck! Jim D/Heathsville, VA

Not a plumber just a homeowner.

Is the toilet running constantly or off and on? Lift the float(the baseball sized thing inside). Hold it to see if this solves the problem. If it did it could be the overflow pipe was cut too low or your float is too high. If you unscrew it that might give you a little leeway or you may have to bend it just a little.

Experts please correct me if I'm giving bad advice.

Devildog