Toilet flush valve crack

[sajo]

I have 3 Mansfield toilets and have replaced each tank's flush valve with a Fluidmaster valve.

In one of the toilets, a few weeks after the installation of the flush valve, a crack develops on the flush valve tailpiece (on the threaded portion where the tank-to-bowl gasket goes) creating a puddle of water on the floor. So far, I have installed 3 flush valves on this particular toilet; and every time a crack would develop a few weeks later.

I have had no problems with my other two toilets, and do not think the crack is from overtightening of the locknut that holds the valve to the tank.

Any suggestions????

[majakdragon]

Have you looked to see if there is a raised area that the nut tightens against? Maybe a piece of the toilet that was not removed before shipping.

[sajo]

Thanks for the reply, Majakdragon.

I did notice that the crack occurred at a location where the tank hole for the flush valve was rough and actually projected out a bit (so that there was not as much of a bevel there). It seems like this pinched the threaded area and caused it to crack.

Can I smooth this out with a file or will it be better to just buy a new tank?

[majakdragon]

I would TRY a file first. You could alos use a rotery type tool such as Dremel, with a sanding drum attachment. This will allow you to clean out any thing within the hole its self. Only take off a small amount as you don't want the hole enlarged beyond the sealing capabilities of the washer.

Good luck and post back.