Toto toilet gmax fill valve shutting off to early, water level too low

Yes, IT may also be a faulty trigger as well, if you can, manually activate the trigger and verify if there is a shut off.

Replace as valve is faulty

WATER LEVEL IS NOT PROPERLY ADJUSTED. REDUCE WATER LEVEL TO FILL LINE

You need Korky Part # R528 available at Home Depot. Instructions are on the package and it takes just a few minutes to change it.

The fill valve needs to be replaced.You need to replace it with a new Gmax fill valve

if it worked fine and now it has stopped....then there is no adjustment that will fix it. If the fill valve is not shutting off you either need to replace the seal in the valve or get a new fill valve. If the water is leaking past the flapper you will need a new flapper.

This is normal, though not so if it is excessive. Try adjusting the fill valve (there is either a ballcock or a float that surrounds the fill valve). With the ballcock, there is a screw at the top of the fill valve to lower the arm, on the other there is a metal clip to pinch and move the float with a large plastic screw for fine tuning.

When you look in the bowl of the toilet, do you see the water trickling? If so then the flapper needs to be replaced.

Also, does the water run intermitentedly? As in every 2 to 5 minutes does the water kick back on to refil the tank? If yes then the answer is yet again the flapper.

Now if the water is constantly running then you can try bending the float arm (the ron that is connected to the big floating ball) down and see if that helps. If not then the next step is to replace the fill valve assembly.

Both of these together will run you about $20-$30.

Remove the tank lid and look at the fill valve. Is it a yellow valve?
This fill valve is common on the Toto Toilets and can easliy plug with debrie.

They can be disassmbled and cleaned. however, I usually just replace the valve with Fluid Master Fill valve.
You will also want to check the water coming into the toilet by turning off the water that supplies the toilet and disconnecting the water supply line. After removing the water supply line turn on the water at the valve to make sure that the water is flowing properly. Check the supply line also to make sure it is not plugged.
Be sure and place a small container to catch the water that will come from the valve. A towell will also help from making too much of a mess.
If the Supply line and the valve are clear the problem is in the fill valve.
The G-Max system denotes the Flushiing system which is a 3" flapper that allows the water from the tank to flow into the bowl quicker.
Good Toilets!

sanray

What you are experiencing is a flapper valve problem. Since I don't know what model you have I will give you a link to the generic GMax unit. Here is the parts breakdown for a GMax

Toto GMax

I would suspect you need part #7 on this diagram a flapper valve. Take the old one with you since different colors ones are used on different models. You should go to the Toto site to locate a dealer first. You can find their site here:

Toto USA

Hope this helps and please remember to rate this!