Toto flush valve adjustment: what does it do?

[Walt]

Hi all. I’m looking at the flush valve in Toto version. There are 1-5 vertical adjustment notches on the piston. What is the purpose of the adjustment?
It seems like it would alter the volume of the cavity inside the piston.
Pictures attached.
I’ve been having problems with the valve getting hung up every couple months and had to make a trip to the vacation rental one time to jiggle the handle for a guest.
The old original valve was set at the highest setting and I didn’t change it. The new valve has an updated design and it came default to the lowest setting.

 

[Reach4]

https://terrylove.com/forums/index....d-i-have-to-hold-the-flush-lever.56174/page-2 #36 has a photo of an older tower. Are your pictures a newer tower?

I expect you are right about the adjustment.

So no hang-ups now, I guess.

 

[Sponsor]

 

[Walt]

The pictures are the old original all-white flush valve like that other post. The new valve is a bit different with black and green parts like below.
The diameter is a little larger. It has a similar adjustment mechanism but with a row of notches and posts on either side of the piston instead of just one side. The new valve assembly fits in the old housing so I didn’t need to disassemble the tank, just swap out the cage and piston.
New one seems to be working fine. Hopefully this fixes my hangup problem. Only time will tell. The old valve only hung up every once in a while and wasn’t repeatable. Hopefully the new design will prevent it.