Toto toilet tank leak

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wolcott

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I recently installed at Toto Drake Toilet, model CST744SL. The toilet flushes beautifully, but there is a chronic leak on the floor that comes from either the back of the toilet, where the tank joins the toilet, or from the tank mounting bolts. This leak occurs without the toilet being flushed, so it was obviously not a leaking wax ring or leak around the bowl to tank gasket. I tried working with the tank mounting bolts, this did not correct it. So, I removed the tank from the bowl, used the tank mounting bolts to plug the tank mounting holes, propped up the tank, and poured in a gallon of water to trace the leak. I noticed the fill valve did not leak, and the tank mounting bolts were leak free, but there were two leaks in the flapper valve area. One was a drip coming past the flapper valve, but I wasn’t concerned about this at the time; it might waste a little water, but would not end up on the floor. The other leak, which worried me more, was a slight leak between the nut that attaches the flapper valve body to the tank and the threads protruding under the tank from the flapper valve body. While it looks like this leak would drain past the tank to bowl gasket into the toilet bowl, I could see where once the tank was tightened down well, it could seal the bowl to tank well enough so the leak could leak out from the top of the tank to bowl gasket to the top of the bowl, and from there to the floor. Now, my questions are:

1. Does it look like this flapper valve nut leak could be the cause of the water on the floor, or could it be something else?

2. If the cause of the leak appears to be the leak past flapper valve body , what is the best way to seal this? Just take it apart and apply RTV or some other sealant, or is there a better way?
 

Terry

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drake_sand_bolt3.jpg

Sanding where the tank bolts go through.

If it's leaking past the flush valve, remove it and sand the inside of the tank.

Then reasemble the parts.

ecodrake_tankbottom.jpg
 
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wolcott

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Many Thanks. I tried sanding the flapper valve gasket contact area in the bottom of the tank well, and then blocked up the tank, plugged the mounting holes, and filled it with water to test it. It looks like this cured the problem of the leak around the flapper valve body, so I reinstalled the tank. In a day or so I'll know for sure if I fixed the problem.
 

Weary_landlord

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My Carrollton tank started leaking badly today. Installed in 2006. I guess I need to have replacement hardware ready, pull the tank, clean/sand/inspect, and reset. My question-- are these washers and gaskets, and the bowl to tank gasket standard items I can find at the hardware store? Or do I need to get everything from Toto?
 

Terry

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Closet bolts are standard on tanks. For a 2006 toilet I would replace the supply line, and perhaps the fill valve too while you're at it.

toto-tank-parts.jpg


Slide the rubber washer onto the brass bolt, drop the bolt in the tank and secure on the bottom with a washer and nut.
The next set of washers and nuts are to secure the tank to the bowl.

No metal washers belong in the tank.
 
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Weary_landlord

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Thanks Terry. Extremely frustrated. I spent over 3 hours tonight struggling to replace tank bolts and tank to bowl gasket. Found a video that said to do bolt head/metal washer/rubber washer/tank/rubber washer/metal washer/nut; bowl/metal washer/wing nut. Leaked badly after the water reached an inch or so. Redid it --bolt head/rubber washer/tank/metal washer/nut; bowl/rubber washer/metal washer/wing nut. Same deal. I managed to crunch the bottom edge of the flush valve a bit-- tried to flex it back, seems too minor to create a seal problem, and if it did, it wouldn't show up with the flapper sealed..... wondering if I have the same problem wolcott above had? I've been looking at flush valve assemblies but mine seems to be discontinued and I can't determine with any confidence what would replace it. The



toto-flush-valve-weary-2.jpg


original looks like this:


I've got this aftermarket dealie in my cart...

flush-valve-3-inch-weary.jpg


That says it fits 774 (which is Carrollton)- does that seem right?

The water comes down through the tank bolt opening on the bowl closest to the supply side, but there's no way to know where it's leaking out of the tank. Thanks for any suggestions on next steps.
 

wjcandee

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There are only 3 places your tank can leak: around the fill valve opening, around the flush valve opening, and around the tank bolts. (Okay, 2 tank bolts so 4 places.)

Unless it's cracked.

And also what you might be interpreting as a tank leak could be a leak from the fill hose or from the connection between the fill hose and fill valve.

I wouldn't mess with the flush valve unless and until you have eliminated the other two. Don't be like the mechanic at the auto dealer who just starts replacing parts without diagnosing the problem.

Why don't you shoot us a picture of the inside of the tank and post it? You'd be surprised what trained eyes can see. Also, make sure you get a decent-quality tank to bowl set if it turns out it's leaking from around a tank bolt.

One way to diagnose is to remove the tank from the toilet after draining it, which you apparently have done anyway, attach the tank bolts properly (i.e. bolt head, rubber washer on inside of tank, then metal washer and nut on the outside of the tank, like in the photo in Terry's post above). Snug them down as Terry advises. Leave the flush valve in place and leave the fill valve in place. Put the tank somewhere where you can look at the bottom of it, and pour in a bucket of water. Where is it leaking? That's where you fix.

And fixing may just mean snugging a nut a little-tighter, consistent with how tight Terry says to tighten. If no leaks, put the tank back on the bowl (don't connect the nuts yet) and reattach the fill hose and turn on the water. Is it leaking now? From by the fill hose? If so, you need a new fill hose or need to address the connection between the fill hose and the fill valve. (From your description, however, my money is on the area around a tank bolt.)

One other observation: a tank to bowl gasket protects the connection between tank and bowl, i.e. during the flush. The connection between the flush valve and tank (the gasket under the flush valve on the inside of the tank) is what keeps water from dripping out around the flush valve. Snugging that would prevent those leaks. When you test it, unless it's immediately-obvious where the leak is, I would do it with the tank-to-bowl gasket OFF, so you can see if there's a leak around the connection between the flush valve and tank. Again, a little snugging of that nut may be all it takes to solve the problem.
 
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Weary_landlord

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Thank you for this thoughtful post. One thing I can eliminate is the fill valve or any of it's connectors-- it's easy to see that's not where the leak is coming from in situ. Ironically I have a complete unused sealed fill valve assembly in the attic for whatever reason.
I was actually thinking the next step might be to prop the tank up on a bucket in the bathtub and see if I could spot the leak so thanks for the confirmation.
It seems like way too much water to be leaking around the stem bolt.
Unfortunately due to work schedule, chronic spinal problems and such it could be a few days until I'm able to do so. I thought I could at least get a head start on getting a new flush assembly on the way.
Thanks again.

There are only 3 places your tank can leak: around the fill valve opening, around the flush valve opening, and around the tank bolts. (Okay, 2 tank bolts so 4 places.)

Unless it's cracked.

And also what you might be interpreting as a tank leak could be a leak from the fill hose or from the connection between the fill hose and fill valve.

I wouldn't mess with the flush valve unless and until you have eliminated the other two. Don't be like the mechanic at the auto dealer who just starts replacing parts without diagnosing the problem.

Why don't you shoot us a picture of the inside of the tank and post it? You'd be surprised what trained eyes can see. Also, make sure you get a decent-quality tank to bowl set if it turns out it's leaking from around a tank bolt.

One way to diagnose is to remove the tank from the toilet after draining it, which you apparently have done anyway, attach the tank bolts properly (i.e. bolt head, rubber washer on inside of tank, then metal washer and nut on the outside of the tank, like in the photo in Terry's post above). Snug them down as Terry advises. Leave the flush valve in place and leave the fill valve in place. Put the tank somewhere where you can look at the bottom of it, and pour in a bucket of water. Where is it leaking? That's where you fix.

And fixing may just mean snugging a nut a little-tighter, consistent with how tight Terry says to tighten. If no leaks, put the tank back on the bowl (don't connect the nuts yet) and reattach the fill hose and turn on the water. Is it leaking now? From by the fill hose? If so, you need a new fill hose or need to address the connection between the fill hose and the fill valve. (From your description, however, my money is on the area around a tank bolt.)

One other observation: a tank to bowl gasket protects the connection between tank and bowl, i.e. during the flush. The connection between the flush valve and tank (the gasket under the flush valve on the inside of the tank) is what keeps water from dripping out around the flush valve. Snugging that would prevent those leaks. When you test it, unless it's immediately-obvious where the leak is, I would do it with the tank-to-bowl gasket OFF, so you can see if there's a leak around the connection between the flush valve and tank. Again, a little snugging of that nut may be all it takes to solve the problem.
 

Weary_landlord

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K guys, I did establish that it was leaking majorly from the base of the flush valve. Couldn't budge the nut. I did order the assembly pictured above. It's in, and no leaks from anything-- except once the water gets above the level of the flapper it leaks through that opening. Am I correct that the flapper needs a little water pressure to push it down so it will seal?
Also, that blue tube (red in the one I received, more inline with other images of the part I've found) is an adjustable extension-- directions say to set it so the top is 1/2" below the handle hole. That would put the level much higher than before, and submerse the top of the fill tower. Is that OK to do?
Thx.
 

Weary_landlord

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All back together... leaks. Are we sure it takes a universal tank to bowl gasket? There's not that much thread exposed on the bottom of the flush valve.... when I look through past the flapper it doesn't seem like the spout of the flush valve is completely seating all the way around. And/or there's no way it's going to fit around the nut to be flush with the tank (like in your pic at the top.)
 

Weary_landlord

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I ordered a tank to bowl gasket off eBay using mfg part number and such. ~ 1/2" larger than the universal gasket-- no wonder it didn't sit right on the flush valve spout. Probably not necessary at all to buy new flush valve assembly.... at least I have the crusty old one as a backup, and a nice $23 large jaw Oil filter/PVC pliers.
 
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