Toto toilet tank isnide unit on the left shoots out water at the top when flushing.

It sounds that your fill valve is the problem, see the imagse and tell us which one is your fill valve, Thanks.

John

Are you saying water shoots out of the ballcock, that's part #2 in the right picture. Much of the water is directed down that little yellow tube to refill the bowl. Which type of ballcock do you have?

There has been a problem with the hunter style o.e.m. ballcock. I prefer a fluidmaster 400-a, as a replacement. Regards tom

Just found this site and I have the same problem as the original question - however, I do not see any actual solution... I have the valve pictured on the right. Is it something in the gaskets inside or can I just tighten the top screw? Valve is 5 years old. It is a
1B1 Master made by Coast Foundary - Pomona Ca.
Thanks
Roo

Also to answer Ballenger's question - yes the water is coming out of the top of item 2 from the right picture.

Agree with Tom: Fluidmaster 400A are good performers...

I agree with Tom and Milo Fluid master 400A is the best to go for, Thanks.

John