How to Fix a Toilet Leaking from the Tank Bolts

new-toilet-tank-bolt-washer-and-gasket

New toilet tank bolt, washer, and gasket

Fixing a toilet is perhaps the last thing a homeowner wants to deal with. It is one of the reasons why renters enjoy being renters and the most common argument against land lording you read about on the Internet. I agree with both of them.

Unfortunately, though, I had to deal with one leaky toilet tank a few days ago. It was not the first time I had to deal with one either, it is part of being a homeowner.

When it comes to water leaks, I do my best to get things fixed as soon as possible. A water leak, no matter how small, can be a homeowner’s worst nightmare, it not only has the potential to cause extensive damage to your home, but it can also cause some health and safety issues.

As soon as I noticed the leak, I got on it. Fortunately, leaky toilets, especially if they are leaking from the tank bolts, are an easy fix. Let me show you how to do it.

FIXING A LEAKY TOILET

There are a few places where a toilet can leak:

  • The bottom/base (hopefully not)
  • The main water connection
  • The tank/bowl connection/gasket
  • The bolts

All of them are easy fixes. However, the first one requires removing the toilet and replacing the wax seal, so it takes more time than any of the others.

If the leak is on the main water connection, you may need to inspect the connection hose as well as the water supply inlet/ballcock, and replace as necessary.

The next two are the ones I show you on this post.

HOW TO FIX A TOILET LEAKING FROM THE TANK BOLTS

Before you start, make sure you have all the parts and tools you need to complete the repair, which are not many, then proceed with step 1.


STEP 1: INSPECT THE AREA AND DETERMINE WHERE THE WATER IS COMING FROM

Before I was able to determine that the toilet was leaking from the tank bolts, I had to inspect it. As I said before, there are a few places where a toilet can leak. Make sure you thoroughly check the area.

Leaks from the bottom or the main water connection should be easier to spot, however, if you look closely between the tank and the bowl, you should also be able to see or feel the water in between the two. Take your time, as this step is necessary to determine what tools or parts you need to fix it.

Once you have determined that the leak is, in fact, coming from the tank bolts, you can go ahead and get a Toilet Tank/Bowl kit.

STEP 2: SHUT OFF THE TOILET SUPPLY VALVE, FLUSH THE TOILET & EMPTY THE TANK

This repair involves completely removing the toilet tank. Before you do that, it is a good idea to completely empty it.

To do this, you can go ahead and shut off the toilet water supply valve, flush the toilet and then use a sponge to get the rest of the water left in the tank.

STEP 3: DISCONNECT THE WATER SUPPLY LINE

Once you have made sure that the tank is completely empty, you can proceed and disconnect the water supply line. Some of them can be removed by hand, others may require a small wrench or channel lock pliers. Be prepared, some water may still leak from the ballcock.

How to fix a leaky toilet tank

Disconnecting the water supply line

STEP 4: REMOVE TOILET TANK, OLD BOLTS

Using the same wrench or channel lock pliers, remove the nuts that hold the toilet tank in place. They should not be really tight as it is recommended to just hand-tight them to avoid breaking the porcelain tank or bowl.

If the bolts start spinning, you will need a screwdriver to hold them inside the tank. If the bolt’s head is completely rusted (it happens), you may need an extra set of pliers to hold them while you try to turn the nut.

Removing nuts from toilet tank bolts

Removing toilet tank bolts

 

When removed, place the tank on top of the toilet bowl, or on any other place that makes it comfortable enough for you to work on it.

STEP 5: REPLACE TANK TO BOWL GASKET – ANOTHER WAY TO FIX A LEAK BETWEEN THE TOILET TANK AND BOWL

This is an optional but, highly recommended step. And it is the one you need to complete when you have a toilet leaking from the tank to bowl gasket.

In this case, since you have already removed the tank, it makes sense to go ahead and replace this gasket as well. I would not want to fix the leak from the bolts and then have to remove the tank a few weeks later to fix a leak from this gasket. I’m sure you wouldn’t want to either.

Replacing toilet tank gasket

Removing the old toilet tank gasket

 

Fixing a leaky toilet installing new toilet tank gasket

Installing a new toilet tank gasket

 

New toilet tank gasket

New toilet tank gasket

STEP 6: INSTALL THE NEW BOLTS, GASKETS, WASHERS AND NUTS

The Toilet Tank/Bowl Kit instructions said that you were supposed to use the bolt, one washer and then one rubber gasket inside the tank, then on the bowl side, another gasket, washer, and nut.

Other than to protect the porcelain, I didn’t see the point of having that extra gasket on the bowl side, the idea is to avoid having leaks from the bolts, so I decided to do it differently.

Since I had two extra washers and nuts from the existing bolts (you should too) I went ahead and not only put the gasket and washer inside the tank but also used the extra ones outside the tank and held them in place with the extra nuts. In my opinion, this double gasket set up should work better than a single gasket one.

New toilet tank gasket and bolts

The new toilet tank gasket and bolts

 

Toilet tank gasket and bolts

The new toilet tank gasket, bolts and extra gaskets and washers outside the tank

 

New toilet tank bolts, gaskets and washers

Using the extra nuts to hold the extra gaskets and washers in place

 

Then, I used the new washers and nuts to hold the tank to the bowl, as described in the next step.

STEP 7: REPOSITION TANK, INSTALL EXTRA WASHERS, AND NUTS

As I described in the previous step, with the bolts in place, I repositioned the tank and used the extra washers and nuts to hold it in place. As I said earlier, do not over tighten the nuts, as this could break the toilet tank, the bowl or both.

Installing the toilet tank

Putting the toilet tank back in place

 

Toilet leaking from tank gasket

Using the slip lock pliers to tighten the nut just a bit

 

STEP 8: RECONNECT THE WATER SUPPLY LINE

With the toilet tank back in place, you can go ahead and reconnect the water supply line. Do not over tighten this one either, as doing so you can damage/break the threads on the ballcock or cause leaks.

Toilet water supply line

Reconnecting the toilet water supply line

 

STEP 9: TURN THE WATER BACK ON AND MAKE SURE THERE ARE NO LEAKS

Before moving on to the next project, turn on the water supply valve and check for leaks.

I recommend checking around the main water connection you just turned on, the tank/bowl connection/gasket and the bolts you just replaced. Make adjustments as necessary.

Readers, have you ever had to deal with a leaking toilet? Was it leaking from any of the parts I mention? Did you enjoy the experience?

Need to fix your own toilet leaking from the tank bolts? This is what you need:



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50 comments

  1. Very informative article, THANK YOU! Although I’ve recently replaced all the working parts of the toilet, I replaced the bolts and thick washers but 1 is still leaking, before I redo the washers, I was wondering if there’s a better, more flexible, high quality one you’d recommend…

    1. Hello, Cynthia,
      Thanks for your comment and for reading our blog.
      I’m sorry your toilet is still leaking. I do not necessarily recommend one or the other but there’s something for everyone.
      Here is a higher-end option, but I’m not sure it works better just because it has a higher price.
      Let us know how it goes!

  2. Hi Tony,
    One point – the fluidmaster kit I have specifically states NOT to use a metal washer inside the tank, between the bolt and the rubber gasket – it states this will cause a leak. The diagram on the kit you linked to also shows no metal washer inside the tank, just bolt head, then rubber gasket.

    I presume this is because the washer spreads out the force a bit too much, preventing sealing of the washer against slightly uneven inner tank surfaces. Looking at the other toilets in my house, they were all configured the way the instructions said.

    I ended up using silicon sealant to fix it, then actually read the instructions properly – I’m not about to take it apart again to test the ‘manufacturer’s method’ now though!

    1. Hello, Jon,
      Thanks for your comment and for reading our blog.
      Great point! I actually used the extra rubber gasket, washer, and nut outside of the tank, like I say on the post, this was a bit overkill, but, we haven’t had any leaks until now, so that means it’s working!
      Glad you were able to fix it with some sealant!
      Have a great week!

  3. I have taken my Tank apart and have replaced my gasket. However it has still been leaking. I can see where it is coming from. And it is from the gasket. Any other ideas on where to look next?

    1. Hello, Lincoln,
      Thanks for your comment and for reading our blog.
      If you’ve replaced everything and it still leaks, you may need to tighten or loosen the nuts a little bit. If they’re loose, they leak, and if they’re too tight, they leak as well!
      Let us know how it goes!

  4. Hi! My toliet tank is leaking so I replaced the bolts. I am trying to pull off the rubber gasket off the nut. I know it is supposed to just pop off but mine is stuck. I can’t get it off to replace it. Any ideas?

    1. Hello, Denise,
      Thanks for your comment and for reading our blog.
      I’m sorry you are having some issues. Why do you have to get the gasket off the nut? Did you get the toilet tank repair kit?
      It comes with everything you need so you don’t have to re-use any of the old parts.

  5. I have an Eljer toilet. My leak is from the tank to the water supply at the top outside of the tank. I cannot find the plumb pak tank to bowl kit for an Eljer. Is there a universal kit that can be used that fits an Eljer brand.

    1. Hello, Patricia,
      Thanks for your comment and for reading our blog.
      I cannot understand exactly where the leak is, pictures would be helpful. However, I would assume that the universal kit fits the Eljer toilet.
      Let us know how it goes!

  6. Great info!
    The last plumber I had used only the rubber washer on the inside of the tank, quite amazing it lasted 20 plus years. The left bolt rubber washer was gone and the right one was maybe 20 percent remaining. Cleaned both the inside and outside of the tank, now I cross my fingers and smile!

    1. Hello, Mark,
      Thanks for your comment and for reading our blog.
      I’m glad to hear our post was helpful, I hope you do not have any leaks for 20 more years!
      Have a great day!

  7. Well written and perfectly clear introduction and solution, with several helpful hints along the way. Thanks for putting this together, you gave me a clear path forward.

  8. As installing toilet seats is not my forte I always have issues with the bolts attaching from toilet tank to bowl. Apparently, the tank bolt holes don’t match the bowl bolt holes. At least the middle bolt, it goes in at an angle. And that is where my problem lies because the rubber gasket does not seal properly. Aghhhh

    1. Hello, Freddy,

      Thanks for your comment and for reading our blog.
      Does your toilet tank has three bolts? I don’t remember seeing one like that. Was it that you break it apart and now cannot put it back together?
      Have you checked that it is not backward? (back of the toilet bowl facing the front of the toilet).

      Let us know what you find out!

  9. I’ve had a similar problem. My tank uses 1/4″ bolts (instead of the normal 5/16″) so at first I was using a runner washer with a larger inside diameter. I eventually was able to find the correct washers and replace them but water is still coming through (very slowly) just one of the bolts.

    The installation of items is in this order: [inside tank] bolt; rubber washer; [outside tank, underside of bowl] metal washer, nut. Still leaking. In an effort to try tightening it further (without cracking the bowl), I added a rubber washer between the bowl and metal washer but that made no difference.

    As a last idea, I was thinking of adding a bead of silicon caulking on the inside of the bowl between the rubber washer and tank AND the bolt and rubber washer…let that dry, then tighten. No idea if adding caulking is a good idea but the normal methods seemed to be exhausted.

    Any thoughts?

    1. Hello, James,

      Thanks for your comment and for reading our blog.
      It seems like, as you said, you’ve tried everything! I would say that it should not hurt to try the silicone considering that even adding the gasket and washer outside of the tank didn’t work. I would put everything together right after applying the silicone (except opening the water) though. Let it dry for as long as the label says it needs to dry and then try again.

      Let us know if the silicone helps to stop the leak!

  10. If I dry out the inside of my tank, can I use expanding foam around the inside bolts to the tank and outside and under the tank where the screws come out. To avoid further leaking if all else fails?

    1. Hello, Patricia,

      Thanks for your comment and for reading our blog.
      It seems like you have been having a hard time dealing with the issue if you are considering foam to fix it. I’m not sure if that will work, I’ve never done it or even heard of anyone doing it.
      Can you share the steps you’ve taken trying to get rid of the leak?

      Thanks!

  11. I bought an Everbilt repair kit from Home Depot that included the bolts, gaskets, and the extra-thick drain tube seal.

    The seal (2-inch) was fine, but the material used for the bolt gaskets did not seal properly. I ended up going to Ace hardware and purchased a Korky brand seal and bolts.

    I left the Home Depot drain tube seal in, but used the Korky brand bolts and gaskets as they are larger diameter and thicker. NO MORE LEAKS!

  12. I have replaced the bolts and the gasket between the tank and bowl. But I still have a leak. I looked at it and it seems to be coming from the gasket. Why is this?? Please, I’ve done everything I can and know how to do but this is really driving me crazy because I’ve been trying to get this fixed for the last week now!!

    1. Hello, Carrie,

      Thanks for your comment and for reading our blog.
      I understand your frustration, as I mention in the post, fixing toilets is not my cup of tea.
      If you followed the procedure, I would try tightening the bolts a bit more, I would start with the bolts kind of loose, and go from there until they stop leaking. I say this because sometimes they leak when they are too tight.
      Let us know how it goes!

  13. I bought the universal kit for the toilet. I was able to remove everything and the gasket was way too small for the toilet, very disappointed, water leaked everywhere. I placed the old flapper unit back in, replaced bolts and seal and every time I flush I get a drip on one bolt.

    1. Good afternoon, Patricia,

      Thanks for your comment and for reading our blog.
      I understand that you replaced the bolts and the gaskets and one of the bolts is still leaking? Have you tried tightening them a bit more?
      Let us know how it goes!

  14. Hello,

    Thanks for the helpful article. I just replaced the bolts connecting the bowl to the tank and I think I over tightened them. Now I’ve got a leak around one of the bolts. Is there anything to be done? Do I have to replace the toilet? Oi vey.

    Thanks for your help,
    Jared

    1. Good afternoon, Jared,
      Glad we could help! If you overtightened the bolts, I would try loosening them a bit. For two reasons, sometimes when they are too tight, they leak (gasket could be damaged, or twisted), and also, because you do not want to break the toilet or the bowl.
      No, I don’t think you need to replace the toilet!
      Give it a try and let us know how it goes!

  15. I replaced my gasket and bolts, I noticed the new gasket was slightly smaller than the old. When I reconnected everything there was leaking from the sides of the toilet. Think I need a bigger gasket?

    1. Good afternoon, Andy,

      Thanks for your comment and for reading our blog.
      We’re sorry to hear that you still have a leak after replacing the bolts and gaskets. From your description, it seems like you may just need to tighten the bolts a bit more. Be careful not to overtighten them though, you don’t want to break your tank or toilet.

      As far as the new gasket being smaller than the old one, it could be because the old gaskets are usually flattened/expanded after being under pressure for a few years.

      Let us know how it goes!

  16. Hello,

    If there is a leak in the tank at the bolts, is it possible that the tank will continue to try to fill up with water, i.e., “running”?

    1. Hello, Ruth,

      Thanks for your comment and for reading our blog.
      That it is totally possible if the toilet is leaking a lot, however, in that case, you would have a lot of water on the bathroom floor all the time.
      If you have that issue, the first thing I would look at is the float valve.

      Let us know how it goes!

  17. So if it’s coming from the bottom base there is no other option but to remove toilet? Been leaking for awhile just now getting to it. Tried tightening bolts to the base to see how it goes.

    1. Hello, Richard,
      Thanks for your comment and for reading our blog.
      Unfortunately, if it is leaking from the bottom, yes, there is no other option but to remove the toilet and replace the wax (or rubber) seal.
      Tightening the bolts could actually break the toilet flange (if it’s plastic) or even the toilet (if it’s metal).
      Let us know how it goes!

      1. Hi, I’ve tried everything replaced the guts every bolt every gasket the only thing that is old is the porcelain and it still leaks from one bolt. I’ve tried double gaskets one gasket washer combo everything and it always leaks. I even tightened it so that it won’t budge and nothing, I must have taken this toilet apart 6 or 7 times and nothing it was leaking from the same bolt when I started. I have had it with this toilet… I have no other option I was going to try to put silicone or some other option along there.

        1. Hello, J,
          Thanks for your comment and for reading our blog.
          I’m so sorry you’ve had so much trouble with the toilet.
          Is there any chance you can try doing exactly what I did? I consider it overkill, but it does not hurt after all you’ve gone through dealing with it.
          I have the bolt & gasket inside the tank and a gasket, washer & nut on the outside. Once you tighten the outside nut you have a double seal with the two gaskets.
          Let me know how it goes!

        2. I had the same issue.. Can’t figure out why it keeps dripping at the bolts.. I even doubled the gaskets and put one in every place possible and it still leaks.. I am wondering if the tank itself be cracked and causing a small leak.

          1. Good afternoon, Alice,

            Thanks for your comment and for reading our blog.
            From your description, it seems like you may have Andy’s problem. You may just need to tighten the bolts a bit more (carefully so you don’t break the tank or the toilet).

            It is hard to tell without looking at it, but have you inspected the tank? I would assume that if the tank is cracked, it would be visible from either the inside or the outside. I still think that you may just need to tighten the bolts a bit more.

            Let us know how it goes!

  18. I recently replaced the bolts on my toilet. It was leaking a drop or so at a time from the bolts. I installed the new bolts and one of them is still leaking a drop at a time. Not sure what to do next.

    1. Hello, David,
      Thanks for your comment and for reading our blog.
      If you replaced the bolts and gaskets but it is still leaking, I would try tightening them a bit more (all of them so the tank remains leveled). Be careful not to overtighten them, though, as you could break the tank or toilet.
      Let us know how it goes!

      1. So I tightened it as much as I could without applying too much force. And when I did I saw some orange stuff coming from the inside of the tank where the bolt is but it is still leaking.

        1. Hello, David,
          I’m sorry to hear that you are still having issues. I would remove the tank once again and make sure all the gaskets are properly seated, not broken, etc, before re-installing it and trying again.

  19. My husband has replace all the guts and put the new gasket on the outside bottom of the tank. To test it he fit it onto the toilet then dropped the bolts through the tank (instead of the bolts being installed on the tank) and proceeded to to tighten the bolts holding the tank to the toilet, when he tests it, it leaks. I suspect it’s because the bolts aren’t attached to the tank with their seals in place before seating the tank on to the toilet. No bolt gaskets = leak from under the tank. To fix it he put some of the old flapper parts back in attached the bolts to the tank WITH the gaskets then seated the tank and attached the tank to the toilet. Guess what? No leak. As far as I can tell the only difference between leaking and not leaking is the bolts actually being attached to the tank with the gaskets before attaching the tank to the toilet? Any thoughts?

    1. Hello Janelle, from your explanation, it seems like your husband was able to figure it out. Yes, the gaskets definitely make the difference. I know it can get confusing from our post as I put gaskets inside and outside the tank (which you don’t really need – I don’t even remember why I had so many gaskets). I’m glad our post helped!

  20. Should I use the extra nut (2) nuts on the bowl? I did not do that as of now. I still have a bolt leaking. Please reply

    1. Hello Barry, you should not need to use the extra nut on the tank as I did. Actually, most repair kits come with just the 2 bolts, 2 rubber gaskets, and 2 nuts.
      I would think that you just need to tighten the nuts a bit more so they put enough pressure on the bolts/rubber gaskets.
      Do not overtighten them, though, as you may end up breaking the tank!

      1. Hello Tony. Thanks for your article. I have a question. I was experiencing a leak around the toilet and determined it was coming from the bottom of the tank. I tightened the bolt in the back of the tank and it seems like the leak stopped. Would you recommend replacing the seal anyway although it stopped?

        1. Hello, Erwin, thanks for your comment and for reading our blog.
          Based on your description I would think that you are safe for now. However, depending on the age of the bolts/gaskets, I would consider replacing them soon before they start leaking again. If they are kind of new, though, perhaps they were not tight enough, to begin with, and that’s why the leak stopped when you tightened the bolt.
          I’m glad we were able to help!

Let us know what you think!