fluidmaster 400a seal leaking

[ruggb]

I replaced the seal but it still leaks.
I have replaced it successfully on another toilet.
It fills to the line and "stops" then continues to leak to the top of the tub and overflows
The float appears free
Why is the seal leaking?

 

[Reach4]

I would get a new fill valve. I don't know why, but they are cheap enough.

I suspect you could undo the top part from the bottom part swap just the tops. I am not a plumber.

 

[Sponsor]

 

[Jadnashua]

Are you sure you got the valve fully seated? Also, if there were any debris on the mating surface when you put in the seal, that could allow it to leak. The only other thing I can think of is if the float is catching on something and not moving freely. That can happen if the two parts are not fully locked into position or you twisted it slightly in the tank where it attaches.