I love my Mansfield toilets. Still made in America!
Remove the lift tower & apply plumbers lube on the seal at the bottom of the tank & at the bottom of the lift tower. Problem fixed & the parts will last longer.
A note about the lift tower: Look at the bottom of the tower & if there is only one 1/4" hole on the bottom, call Mansfield & tell them that you want the modified version (which has two holes instead of one). The improved part will keep the tower up longer allowing more water to pass on every flush. Much better.
Thankfully, I also came across this thread and it cost me $1.79 for a new flush valve seal and 5 minutes of labor to fix this problem. Being a woman, I am taken advantage of alot by the service industry. This was a wonderful find for me!
I have four mansfield manufactured toilets in my home (not my choice... put in by contractor in new build). I've had problems with all of them... and the same problem... I've had to fix all of them myself. They eventually stop flushing... water runs forever, etc. Will eventually replace all of them with something of better quality.
Wow should have done some internet research before investing at least 2 hours of time, 2 trips to Home Depot,and money on a new handle for my hard to flush Mansfield. Thanks to this site I spoke with someone at Mansfield this morning 877-850-3060 and was also told to replace the red seal, which they are sending me free of charge. Yay!!