Toto Drake THU440-A Flush Tower Issues

[SH_82]

I have a new Toto Drake that was flushing great for about 5-6 months. Then all of a sudden the flush tower occasionally does not close completely causing the water to run.

This occurs maybe once every 7-8 flushes.

What I've noticed is that with this dual flush system it only seems to have trouble when the water level in the tank (after the flush) is low. When the handle is pulled, and the tower is pulled up out of the water completely, and then tries to drop down back into the water and then seal...it gets stopped at the surface of the water and doesn't want to continue submerging itself for the proper seal.

The quick fix is to pull the handle and ensure the release gives it enough speed in the drop to close properly.

Troubleshooting taken so far:
1. Adjusted the trip lever arm by bending so that it is more centered over the tower
2. Adjusted the flapper chain so there is not much slack
3. Messed with the 1-5 settings on the tower itself. I wasn't sure what this specifically did but I got desperate and moved it from 3 to 2.

My other, cheaper Toto Entrada that uses the conventional flapper has worked like a dream, which has made this even more frustrating.

Any thoughts on what else I can do to continue troubleshooting this issue?

Thanks for the help!

 

[Reach4]

If the water level in the tank is low at times before a flush, I think that would be the fill valve.

Did you mean when the water level in the tank (after before the flush) is low?

 

[Sponsor]

 

[SH_82]

If the water level in the tank is low at times before a flush, I think that would be the fill valve.

Did you mean when the water level in the tank (after before the flush) is low?

Yes I guess that's what I'm getting at. With a dual flush system is it expected that the water level in the tank would sometimes be low? Or should it always refill to the maximum level?

I'm going to remove the tank lid for the remainder of the day and pay closer attention to those levels before and after flushes.

From what I can tell the fill valve appears to be working optimally but I'm not sure the signs to look for in a failing part there.

 

[Reach4]

Yes I guess that's what I'm getting at. With a dual flush system is it expected that the water level in the tank would sometimes be low? Or should it always refill to the maximum level?

I think so.

Maybe some lube to the sliding surfaces of the float system could help, but I don't know. Setting the fill level a little higher might work around this.

I think the fill valve is ignorant of the dual flush part. It just knows water levels.