Acme How To Logo Acme How To Logo
Related Articles
Plumbing Section

Plumbing Emergencies


Plumbing Basics

Appliance Plumbing

DISCLOSURE: This post may contain affiliate links, meaning when you click the links, we may receive a commission.


Sign up to receive our free Maintenance Reminder Newsletter

Learn More

How To Check or Replace the Tank Bolts

How to Check the Tank Bolts

A two piece toilet has a set of bolts that secure the tank to the bowl. These bolts go through a hole in the bottom of the tank and through matching holes in the bowl. Typically rubber washers fit between the bolt head and the inside of the tank. Washers or spacers may fit between the tank and the bowl and finally a rubber, plastic or metal washer fits onto the bolt between the bowl and the nut that secures it in place.

Caution: Please read our safety information before attempting any testing, maintenance or repairs.

If the washer is misaligned, has been damaged or has cracked or hardened with age, it may leak water from the tank. This typically results in water on the floor beneath the tank. Water droplets on the end of the bolt under the bowl is a telltale sign.

How to Replace the Tank Bolts

To replace the bolts or washers, turn off the water supply valve and flush the toilet. Place a large towel on the ground beneath the tank to catch any spillage. Reach under the bowl and loosen the nut, you may be able to do it by hand or you may need a pair of pliers or slip joint pliers depending on the type of nut. If the bolt turns when the nut is turned, you may need an assistant to hold a screwdriver in the bolt head while you turn the nut. If the nut is seized to the bolt you can try penetrating oil like 3-in-1 or WD-40 to loosen it.

How To Remove Stuck Corroded Toilet Tank Bolts

If a tank bolt just turns but won't unscrew from the nut, it might be necessary to cut the bolt off to remove it. Use caution or you may damage the vitreous china; once broken, you may have to replace the entire toilet. One method it to use a hacksaw blade (just the blade alone or possibly small hack saw for tight spaces if there is room). It will help to bend the blade to give you something to hold on to. Wrap the par tyou hold with some duct tape. Place the blade under the head, inside the tank and cut through the bolt. You may also be able to access and cut the bolt from between the tank and bowl. The bolts are brass, which is a relatively soft metal and is not very difficult to cut.

If you cannot cut the bolt, you may be able to drill it out. This can be risky if you accidentally drill into the china, it is likely to break. Use a drill bit for drilling metal. Choose a size that is slightly smaller than the diameter of the bolt. Dry the interior of the tank before using an electric drill. Place the bit in the center of the bolt head and begin drilling at a very low speed. Typically the bolts are made of brass and are fairly easy to drill. Drill roughly a 1/4 of an inch to remove most of the material securing the head to the bolt shank. Now try cutting with a hacksaw blade to remove the last small amount of material.

How To Install New Tank Bolts

Place any spacers or washers between the tank and bowl and place the tank onto the bowl. Align the holes and slip a bolt, with a washer, into each hole. While holding the tank in place (an assistant may be necessary) place a washer on the bolt, under the bowl and then fasten the nut. Tighten the nut by hand and then only a little more with a tool, as needed. Over tightening will break the tank or bowl china which require complete replacement.

Turn on the water and let the tank refill. Check for leaks. Flush the toilet and check again for leaks.

Search for Articles on Acme How To

Ask a Plumber Now

We have partnered with JustAnswer so that you can get an answer ASAP.