How much "leak" is normal in a toilet flap

Joined
Aug 5, 2002
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Good old fashion Fluid Master valve in a builder grade 90s 1.6L round toilet in the kids' bathroom.

Normally it is used maybe 2-3 times a day but when I was quarantined with that bathroom / bedroom I noticed it would "refill" about twice a day, basically it would leak about maybe 1/4-1/2 gal a day from my testing, and confirmed when I add food coloring in the tank and watch overnight.

I know leak is bad but I also understand that almost every gasket will leak a little eventually. When would you notice and when would you "fix" it?

How much do you expect a NEW one would leak normally?

1CCF is about $6 here, which is about 750 gallons and that means that leak is about 0.2-0.4 cents a day.
 
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MIchigan
Take the Flapper off and clean it and apply something to restore the rubber. Also take a scotchbrite pad and scrub the toilet valve where the flapper seats to the toilet.
 
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Age doesn't matter. If it works, great. If it doesn't then buy a new one.

Thats one way to look at it, I get that.

Why would anyone be looking at it to begin with if it worked great though.

I don't think I'd bother to repair something like a toilet flapper that was beyond say 10 years old.
 
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My neighbor, the plumber, showed me how to test for sloooowwwww leaks in the toilet. Take a flashlight and turn off all the lights so it's good and dark and shine the light into the bowl, it there is any kind of leak you will see the water move. Our water bill is high enough the way it is plus it's a waste of water.
 
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We have hard water here in Iowa. I’ve replaced all the toilet guts in our house over the last 13 years. They usually get hard and leak. Replacement parts are easily had at Menards.

Just my $0.02
 

JTK

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Aug 14, 2003
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Buffalo, NY
All you have to do to test for a flapper leak is shut the water supply off to the toilet. If the toilet tank empties itself over night, the flush valve is leaking by.

The cheaper ones like fluidmaster only last a few years at best with my municipal water supply. Better brands last longer.

I do what I can to avoid waste water because of my ~50yr/old septic system.
 
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I don't play games with fixing them. I just replace the entire setup. Cheaper than a $1k water bill. That way you know you're good for at least another 5-10 years. Why waste time/water trying to keep an eye on it?
 
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Flap valves last a few years. If you start hearing your toilet fill itself without anybody having flushed it's time to replace the valve. Trying to refurbish an old toilet flap valve would e like trying to refurbish worn wiper blades.

I did 3 of mine over 2 years ago. Still working without that annoying fill sound.
 

PandaBear

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My neighbor, the plumber, showed me how to test for sloooowwwww leaks in the toilet. Take a flashlight and turn off all the lights so it's good and dark and shine the light into the bowl, it there is any kind of leak you will see the water move. Our water bill is high enough the way it is plus it's a waste of water.
I did that and see nothing. Proven phantom leak with food coloring.

I shoot for 0% leaks.

Is the fill valve leaking or the flapper? With either part, maybe it just needs cleaning. Attempt clean/repair first, then replace if needed. Chlorine and other chemicals will erode rubber components.
It is the flapper. I even turned off the fill valve and see if water slowly goes down overnight and it did. The amount is small, proven with food coloring in the tank that it is the flapper. What I want to know is whether this "sloooooooooow" leak is normal just like the shower tub filler diverter "leak" a little even if new.


If this is not normal I'll go ahead and replace it with a whole new one. My time is worth more than some vaseline to extend a few years but have to keep an eye on it.
 
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