If you’ve ever lifted the lid on your toilet bowl tank, you’ve seen the two large nuts and bolts that secure that tank to the bowl. Over time, you may find that these look kind of gross from the rust that has built up on the submerged bolts. This is not only unattractive  – it can also lead to leaks. Why do toilet bolts rust? After toilets have been in place for some time, the natural environment of the tank will lead to corrosion. Rust is naturally caused because of the constant water that is in contact with the bolts. When you notice your tank bolts are rusted, especially if there is a significant amount of rust, you may want to consider replacing the bolts. The rust will continue to add up over time and can make the replacement process even more difficult. Also, even if you are not seeing problems at this time, it is likely that you will see them in the near future.

Why Do Toilet Bolts Rust?

The inside of your toilet tank is not the easiest environment for an average bolt to live in, and it only makes sense that rust would accumulate over time. Most of these bolts are standard quality and made from simple metals that are susceptible to rusting. If you have opened your toilet tank recently and noticed two balls of rust around your toilet tank bolts, this is what we are talking about. Years of condensation and water exposure to the bolts in your tank have caused rust to form. This rust is the result of oxidation, which is the result of iron, steel, or another type of metal coming into contact with water and oxygen over time. While there are actually three types of rust, the most commonly seen rust you will see in the tank is red rust. The problem here is that this accumulation of rust can actually cause the metal to break down over time.

Why Replace Your Toilet Tank Bolts?

Taking on plumbing work is not something many homeowners want to do, but this can be extremely important if you do have rusted toilet bowl bolts. The rust can cause the washers to move from their correct location and can cause leakage from the bowl. If you notice rust in your tank, it is best to make the replacement before the bolts begin to falter.

How to Prep for Removing Rusted Bolts

Once you notice rusted bolts in your tank, you will want to begin the process of replacing them with new ones. There are a few key steps that you must take to ensure this process goes as smoothly as possible. The steps to replacing your rusted bolts are:
  1. Ensure that any leakage you see from your toilet is actually coming from these bolts. If you have seen leakage already, you should notice if the bolts are rusted or not. You will want to check between the tank and the bowl for any water to ensure that these bolts are, in fact, leaking.
  2. Turn off the water to the tank. Of course, you do not want to start doing any plumbing work before doing this. You should shut off the toilet supply valve and flush the toilet enough to empty the tank. If you are noticing some water left behind and want it out, you can use a sponge or towel to dry this up.
  3. Fully disconnect the water supply line once the tank is completely empty. This can often be done by hand, but others can require you to have a small wrench or channel lock pliers. There is a chance that you will notice some water leaking from the line once it is disconnected.

Removing the Rusted Bolts

Once you have stopped the water flow and have prepped your tank, it is time to remove the rusted bolts. This can be a bit of a challenge depending on the severity of the rust and corrosion.

If Rust Isn’t Too Bad

For lesser-rusted bolts, you can simply use a wrench or channel lock pliers to remove the nuts that hold the toilet tank in place, they should not be super tight, but this will differ based on the toilet. If the bolts start to spin, you’ll need to hold them in place using a screwdriver. There are times when the head of the bolt is too rusted to hold with the screwdriver. If you are running into this issue, you will want to use an extra pair of pliers to hold them in place.

For Severe Rust

There is a chance that the rust is so rampant that you are really struggling with removing the bolts, which means you need to bring in some heavier duty equipment.
  • Remove the bolt caps to expose the washer and nuts.
  • Clear rust particles on the hardware, using a steel brush.
  • If you can’t remove the caps, you may want to grab a hacksaw and cut through the bolt.

Cutting Through the Bolts

Most toilet bolts are made from brass, which is relatively easy to cut and should be effectively cut through with a hacksaw. If you are worried that you are going to damage the toilet using a hacksaw, you can use just the blade to cut through the bolt. Once you have cut through the bolt, you can pull the tank off of the bowl, and you will be left with the stubs of the bolt sticking out, lightly tap this to push the bolt head out.

Drilling the Bolts Out

If you have tried to cut the bolt but are still struggling with this process, you can also drill the bolt out using a small drill head designed for metal. It is critical that you are very careful during this, or you will break the porcelain. You want to ensure that the tank is completely dry, place the bit in the center of the bolt head, then begin drilling at a very low speed. Drill for about ¼  of an inch to remove most of the material securing the head, then try cutting once again to remove the remainder of the bolt.

Installing the New Tank Bolts

Once you have the bolt removed from your toilet, it is important that you find the right-sized bolt, washers, and nut to replace on your toilet. If these pieces do not line up properly, it will allow water to leak through. If you are unsure of which size you need, you can take the removed pieces to a hardware store or search for your exact toilet make and model to ensure you are choosing the correct size. The easy steps you need to follow to replace the bolts are:
  1. Clean up the area where the old bolt head was to remove any remaining rust. This can cause the washer to sit incorrectly and lead to another leak.
  2. Place any spacers or washers between the tank and bowl, then place the tank onto the bowl. Make sure you align the holes and then slip a bolt with a washer into each of the holes.
  3. You may need to grab a helper for the next step because you will need to hold the tan in place and then place a washer on the bolt under the bowl, then fasten the nut into place.
  4. You will want to use your hand to tighten the nut into place, only tightening it slightly further with a tool. You should never overtighten the nut, or you can risk breaking the tank and causing far more damage.
  5. You will then turn on the water and let the tank refill, make sure to check for leaks during this process. Make sure to flush the toilet a couple of times and check again for any leaks.

Learn More

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