Toto GMax flush System

[Fastco05]

:mad: My toto flushes great, but when it fills the tank it slows then continues to fill until it overflow down the overflow tube.

How do I adjust the gmax so it does not overfill the tank?:confused:

Thanks,

Fastco05

[DUNBAR PLUMBING]

I have no success working on these fill valves. They are the first to clog against 400A Fluidmasters.


I wish there was a better way to work on these.

[PLUMBER RICK]

chances are the diaphragm is worn out. unless you actually moved the ballcock level by removing the locking clip and rotated the shank to make it taller. the ballcock is leaking, worn.

you can remove the plastic cover by squeezing the sides and snapping it off. this will expose the actual float. try pushing down on the pivot to close the valve. if it still runs, replace the hunter diaphragm or just swap it out to a 400a fluidmaster and you'll be much happier.

rick.

[Herk]

There's a slot on the side of the G-Max. When the water level reaches it and flows in, the valve should shut off. The trick is positioning it where the valve shuts off with the water level about 5/8" below the overflow tube.

You have to be careful with G-Max and Korky fill valves because too much pressure twisting on them and they'll break. If you need to reset the level, you have to remove the clip slipped in between the two tubular pieces first, then replace it when you've got it where you want it.

You can take it apart to clean debris, and Korkys usually have an instruction sheet on how to disassemble them for cleaning. But if you try to remove the rubber seal inside the cap, you'll probably damage it.

G-Max and plain Jane Korky are not identical - the G-Max has the proper refill amount for Toto.

[Obama the Plumber]

If the G-Max valve is not shutting off, just pop a new assembly cap on it.
They are about $2.50 at Lowes.
Even a homeowner can replace the part without tools in less then a minute.