# One of the bolts on the toilet tank is leaking.



## intelpcguy (May 10, 2015)

*keep some of the old parts*

what I do when replacing tank bolts is 2 buy 2 kits, or keep the old brass washer / and nuts. I install the new bolts. rubber washer, brass washer in the tank, and use the old brass washer and old nut to tighten the new bolt / new rubber washer/ new brass washer to the tank. This will stop any leak, then I install tank to lower, and secure the tank with remaining nut / washer, tightening only tight enough so there are no leaks at the big rubber doughnut and to minimize the tank rocking back and forth or side to side.


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## AllanJ (Nov 24, 2007)

Disassemble everything and make sure that the inside surface of the tank does not have burrs or roughness around the mounting holes at the bottom.

You cannot have metal against metal inside the tank, otherwise you *will* get leakage.

So from the top you have the bolt head then a rubber washer with no metal washer in between, inserted into the mounting hole on the tank bottom. Add a metal washer and nut from below. Now install the tank on the bowl and use the remaining pieces.

In a few instances the mounting hole is so large that the rubber washer inside the tank becomes too deformed without a metal washer above it. Here, use two rubber washers with a metal washer in between.

In a few instances there is not enough of a gap between the tank and the bowl to put a nut on the tank bolt prior to final assembly. Said nut must not touch the bowl upper rear flange. Here you have to use the nut under the bowl upper rear flange to hold the seal inside the tank as well as hold the tank in place.


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## wrangler (Oct 9, 2008)

I have always applied silicone to the rubber washer and bolt before putting it back together as an added measure. The Toto commodes I used to install came with two nuts and washers to install as Intel suggested, but even then, I would use a little silicone. I also ran a bead around the neoprene tank to bowl gasket since I had the silicone there and handy. A little overkill, but we didn't get paid for going back to our own jobs for leaks.


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## blazito (Sep 27, 2014)

intelpcguy said:


> what I do when replacing tank bolts is 2 buy 2 kits, or keep the old brass washer / and nuts. I install the new bolts. rubber washer, brass washer in the tank, and use the old brass washer and old nut to tighten the new bolt / new rubber washer/ new brass washer to the tank. This will stop any leak, then I install tank to lower, and secure the tank with remaining nut / washer, tightening only tight enough so there are no leaks at the big rubber doughnut and to minimize the tank rocking back and forth or side to side.



I did this exactly as you described. The bolt started to leak after 3 hours. Pretty frustrated.


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## intelpcguy (May 10, 2015)

the only time I have leaks with the "sandwich" method was either I did not tighten the bolt "sandwich" assembly tight enough or the new rubber washer was not a tight fit around the new bolt.


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## blazito (Sep 27, 2014)

I tightened the sandwich assembly pretty good with a wrench. It's always the same bolt leaking and for some reason hours after I fill the tank. I'm thinking the bolt hole is causing the problem. Both holes are kind of rough on the top where the rubber gasket seats. Then again, the entire surface inside of the tank has a rough texture.


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## jmon (Nov 5, 2012)

There was a post awhile back similar to this and one of the plumbers recommended using a cone compression type washer. It worked for the original poster. I did a search can't seem to find the post. It was something like this;

Don't know if it will help in your situation, just a suggestion.


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## jmon (Nov 5, 2012)

No need to buy a whole new kit either, any hardware or big box store carry the cone washers for about twenty five cents. Just bring the bolt with you to make sure you get the right size. :thumbsup:

If that one bolt still leaks, as mentioned, you may have a hair line crack/fissure not visible by the naked eye allowing a little water to seep through around the bolt hole (possible but not likely). Place a small cup under it to see how much it's leaking.


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## blazito (Sep 27, 2014)

Thanks for all the replies. Haven't had the time to further mess with it. But I was wondering if you guys have any suggestions on which sealant works best in this situation. I have read that regular silicone does not adhere to rubber gaskets all too well. Is there a better sealant I can use around the rubber gaskets?

Thanks.


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## SeniorSitizen (Sep 10, 2012)

I've had good success if the tube reads " *Adhesive* Sealant "


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## blazito (Sep 27, 2014)

So would a sealant like this work?

http://www.homedepot.com/p/Eco-Bond-10-1-oz-Kitchen-and-Bath-Adhesive-2-Pack-KBT100-2-pk/203350108


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## SeniorSitizen (Sep 10, 2012)

blazito said:


> So would a sealant like this work?
> 
> http://www.homedepot.com/p/Eco-Bond-10-1-oz-Kitchen-and-Bath-Adhesive-2-Pack-KBT100-2-pk/203350108


It very possibly could work but I should have been more specific in my other reply and said Silicone Adhesive Sealant since that is what I've used for many years.


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## ChuckF. (Aug 25, 2013)

You can also use plumber's putty. Roll a dab of it between your palms, into a string, and wrap that around and between each part of the bolt, washers, etc.


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## blazito (Sep 27, 2014)

UPDATE:

So I sealed up the bolt assembly with aquarium silicone. Used the rubber gaskets on both sides of the tank and used silicone on both sides. It's 100% sealed up. Installed the tank and filled it up. 7 hours later there was a drip from the same bolt. I said to myself, no way its leaking from the bolt. Had someone lift the tank a bit, and realized it's actually dripping from the flush valve's nylon nut. I drained the tank and re-tightened the flush valve assembly. Same deal, still drips. 

Is this a compatibility problem? I'm using a fluidmaster flush valve on a toto toilet. Is there an additional seal ring I can place inside the tank for the flush valve to seal better? Or should I try a different flush valve like a American standard 3"?


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## jmon (Nov 5, 2012)

I've never had any problem with the fluid master flush valve. They usually fit most toilets. Don't know if toto has their own specific designed or not.

Only thing I can suggest is make sure the internal seal and external seal are properly position and not kinked, then make sure the locking nut is tightened down and not cross threaded. I'm sure you already done this numerous times.

Others will be along, I'm sure someone has run across this before and found a fix.


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## wrangler (Oct 9, 2008)

You say additional washer: the shank washer (rubber washer) is on the inside of the tank, correct?


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## blazito (Sep 27, 2014)

wrangler said:


> You say additional washer: the shank washer (rubber washer) is on the inside of the tank, correct?


Here is the fluidmaster flush valve. It has a rubber base as a seal without any additional washers.


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## wrangler (Oct 9, 2008)

Sorry, was thinking fill valve. But there should be a neoprene gasket that attaches at the underside of that flush valve where it meets the bowl. Again, some may say overkill, but another step I always took ( esp since I already had the silicone handy from a step mentioned in prior post) was to run a bead of silicone around the threads, push on the gasket, and then a ring around the bottom of the gasket itself where it will meet the bowl.


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## blazito (Sep 27, 2014)

I ended up putting silicone under the gasket, tightened the flush valve down and a bead of silicone where the gasket meets the tank. Hasn't leaked in 4 days now. 

Thanks to all!


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## jmon (Nov 5, 2012)

Easy solution to the problem. Glad it worked out for you. Thanks for the update.


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## Yodaman (Mar 9, 2015)

I know I am a month too late. Next time, you could try wetting the sealing surfaces with teflon plumbers past. The past fills in any irregularities in either of the mating surfaces and almost always makes a good seal on the first attempt. I am sure the silicone did the same thing and is just as good or better. Glad you got it solved and resolved.


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## wrangler (Oct 9, 2008)

Glad to hear you got it fixed. Thanks for the update.


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