My one year old toilet has been leaking after filling. Is also make a terrible noise,sometimes during this time. I don't know what to adjust, or if something just need to be replaced. It seems that this is new for this problem! Thanks Suzy

Most likely it just needs a new flapper. Have you used those tidy bowl cleaning things in the tank? They will destroy a flapper in a fairly short time frame.

Suzy remove the tank cover let the fill valve fill to the stop point just under the over flow tube and turn the stop valve off.wait fifteen minutes and see if the water level where you turned the stop off has changed/lowered.That is a flapper seal type problem.If this is not the case you need to provide us with the model number of your tank stamped in it. So we can tell which fill valve type you have.It is most likely an easy fix.

As a plumber, not a consumer.


Every single Toto toilet I installed, I had to return within 2 years and take out/remove the Gmax Fill Valve and replace the original flapper that came with the toilet.


The fill valve is a Korky, aka Hunter fill valve. This company (Toto) is fully aware that they are sending out a fill valve that has a known problem, a $3.47 fix that even the smallest piece of dirt and debri can cause the fill valve to malfunction in these toilets.

Fluidmaster 400A, the fill valve that is now in nearly all name brand toilets is the cure for this problem, not replacing the GMAX fill valve.

I lost my profit margins on every Toto toilet I installed, and when I called them to complain and get compensated for not only the loss of time, but the cost of replacement parts,


they fought me diligently, like they were not in the business to keep customers/plumbers happy with their product.

And that's why I'm on here now, telling the facts of my experience.


I've removed Hunter fill valves over the years as well, same thing always; fill valve is sporatically filling the tank.

The large red flapper is supposed to be chemical resistant, and as I admit readily there's elevated chlorine levels in my region, these flappers are not holding up to any distinguished timeline that would be customary to "regular" conditions in relation to chlorine exposure.

The center of the flapper has a tendency to drop, given its large surface area and combine that with the weight of the water imposing down across the opening of that flush valve, the flapper eventually fails. The texture of this flapper becomes very eroded, swelled up and defective in short time.

Knowing the history of other Korky flappers not following the same erosion pattern speaks volumes to what Toto had in mind for job security with their product lines.

I managed to get 2 red flappers, 2 blue flappers out of Toto for my hardship and the hard line that "We do not cover any labor charges that arise out of malfunction or defect of our products."

They were going to send me the repair kits for the Korky fill valve and told them NO. I'm removing the fill valve and installing a Fluidmaster 400A for the best interest of the customer and the non-existent profit margin the Toto Toilet robbed me of.

And when I hear the employees at the supply house speak of these toilets... obviously they've been brainwashed to do or say anything that leads to a sale.

Well, I tried that, tried to believe that the customer paying 30%-50% more for a toilet was a good idea, nevermind the obvious "made in vietnam" stickers that you can't miss when the box is opened.

This "awareness" has pummelled the sales of that brand over the past few years and customers can't rely on just what the plumber says. I ate crow when I had issues, customer looking at me like I led them down a dark road with only profit margins in mind.

The consumer and the plumber want reliability, not the total ignorance of an obvious problem with the two crucial wearable parts inside this toilet that makes the biggest difference in the world when it has to perform as good or better than its competition, and it is not.

I'd be honestly speaking my mind on this matter if they was giving me these toilets 50% under cost, with a cozy relationship with my supplier.

I'm notorious for being blunt honest, and this is another one of those times where a product manufacture doesn't adhere.

I don't care if you live in Alabama, or Texas, or Ohio and put in 100 of these without issue... look to these plumbing forums with these identical questions/problems that keep arising from the same problem, over and over.


Fluidmaster 400A's coming straight from the factories in numerous well known brands is happening for a reason folks.


Every one of those toilets I replaced the fill valve in, NONE have had issues with the Fill Valve.

Every one of those toilets I replaced the flapper in, NONE have had issues with the flapper leaking. I find that quite disturbing that there's two different designs of a flapper, one that's intentionally failing in short time against the replacement that gets an obviously longer life, whether or not the chlorine levels are elevated.


I'm not going to listen or cater to anyone short of a Toto rep coming on here. Thank goodness the market didn't have a large share with this product name, and I'm glad I didn't install a lot of them. Excessive pricing kept that from happening.

Now that the M.A.P. scores are showing a lot of competition and many others doing far better in the gram test, their prices plunged to reflect where they were way off base, and sales show it now.

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Everything in Plumbing can be repaired or replaced.



Edited 1 times.

I have had problems with the Toto fill valves.I have not had any problems with the flapper.Maybe our water is differant here.I have installed fluidmasters in Totos and found that they don't put out enough water to fill the bowl all the way in the short time that they are on.Toto has changed there fillvalve (It's about Time).
By the way I have had some bad fluidmasters recently.I had to replace the black rubber disc.(I tried flushing it).

I have not had ANY warranty problems with TOTO toilets, because I only install them when the customer supplies them. When I repair them, I use Fluidmaster fill valves and Korky flappers. Any fixtures I do sell have a proper profit margin in the price, or the customer can buy them themselves, and warranty them through whoever they bought them from.

I have (4) TOTO MS853113S#11 toilets purchased in 2011. After a couple years they all began leaking past the flapper intermittently. There was no build-up or flaws on the seal surfaces. Evaluating the stock flapper I noticed two issues. 1. The flapper can shift on the hinge posts +/- 1/4" The lateral shifting causes the flapper to barely seal. 2. The length of the flapper is too short and the flush rim that contacts the flapper is nearly visible. Interestingly, I purchased Korky 2021BP G-Max Flappers and the flapper is wider and longer. The fit to the hinge posts is perfect and the longer flapper better covers the hole. My conclusion is either the stock flappers were the wrong parts or the design is flawed. Also the Korky flapper was softer and more flexible than the stock flapper perhaps from chemical attack over time. The bottom line is the Korky flapper fits better and to this point does not leak.

Thank you for your advice but the cheaper fluid master valve turned out to be extremely noisy. Functionally, it worked fine but I couldn't stand the noise it made when I flushed. I finally had to replace it with the Genuine Toto Korky valve to get my sanity back. This is a matter of function over esthetics. If you're used to driving a BMW and suddenly replaced the muffler with some aftermarket product, its going to sound like you're driving a piece of junk. We bought the Toto toilet because we have small children who are sensitive to noise.