How to Remove Plastic Nut from Toilet Tank

A toilet tank features plastic lock nuts that secure different fixtures in place. These plastic nuts are strong enough to provide secure support for the fill valve and other toilet fixtures. But over time, the locknuts can corrode or get damaged, making them hard to remove. Regardless of what triggered you to remove the nut, this guide highlights a step-by-step process on how to remove a plastic nut from the toilet tank.

Reasons to Remove Plastic Nuts From the Toilet Tank

You may be wondering why it would be necessary to remove plastic nuts from your toilet tank. In a nutshell, here are some of the most important reasons why:

  • You Want to Replace the Tank: Sometimes, you might want to replace the toilet tank, and this requires you to remove the plastic nut beforehand. You’ll also want to remove the plastic nuts when removing old parts and installing new ones.
  • You Need to Adjust the Water Flow: If you don’t like how your toilet flushes and want to adjust the water flow, you’ll need to remove the nuts first.
  • The Plastic Nut Is Leaking: Over time, the plastic nut may begin to leak, and the only way to fix the issue is to replace it with a new one.

Tools You Need to Remove the Plastic Nut

Removing the locknut from the tank is one of the easiest DIY projects. You only need a few simple tools: 

  • Pliers
  • Channellock 
  • Adjustable wrench, 
  • A screwdriver
  • Rubber gloves
  • A new plastic nut (if necessary).

Steps to Remove Plastic Nut From Your Toilet Tank

Plastic locknuts are designed to hold together different components of your toilet, including the water supply hose and fill valve. Below is a quick video to help you learn how to remove the plastic nuts from your toilet tank. All you need could be some good old-fashioned elbow grease. This is one of the most straightforward DIY projects you could do in your home.

Always be extra careful when getting out the plastic locknut from the tank to avoid cracking it and flooding your bathroom with water. Here is a step-by-step process to help you remove the plastic nut from the toilet tank like a pro:

Step 1: Close the Fill Valve

You should first shut off the toilet’s water supply by turning the handle that feeds the water tank into the valve. You can do this by turning the handle clockwise on the water valve until it stops. If you can’t find the water shut-off valve in your bathroom, you can completely shut off the main water supply to your home. You will need to go into your attic to find a different valve that shuts off the main water supply to your home. You can find this valve in your basement, garage, or even outside of your house.

Step 2: Place a Towel Under Your Toilet Tank

Even if you close the hose that supplies your house with water, there may be leaks somewhere. Maybe your toilet is leaking from the bolts that hold the water in the tank. If that is the case, place a damp towel inside your toilet bowl to absorb any water that may leak. If something is spilling or leaks from the toilet bowl, it will be easier to clean up the water quickly.

Step 3: Remove the Toilet Tank Lid 

Grab your toilet lid and raise it up to reveal what’s in your tank. You may find that the lid is still stiff and hard to remove if it’s been a long time since you last put the lid on the tank. If it was a while ago, you might have to clean it before putting it back on.

Step 4: Drain Water From the Toilet Tank

This step is necessary before you start draining the water from your tank. If you flush the toilet completely, all the water in your toilet tank will start pouring out of your toilet bowl. Repeat this process until all the water in your tank is gone. If you are unable to get all the water out of the tank, you can try one of the following methods:

  • Sponge and bucket: After you cut the water supply to your home, use a sponge to soak up any remaining water, then pour it into a bucket.
  • If you cannot get all the water out of your toilet tank, you can use a Stanley dry/wet vacuum to remove all the remaining water. 
  • Use a dry towel instead of a sponge: If you do not have a sponge, you can use a dry towel to absorb the water. Try to drain as much water as possible from the inside of your plastic tank before you start to clean it.

Step 5: Remove the Plastic Coupling 

After you have removed the top layer of your toilet bowl and cleared the water inside, you will need to remove the plastic fitting that holds it in place. It’s an easy-to-disconnect overflow tube. At this point, you can drain out the last bits of water that are in your toilet tank. Once you do that, you will need to remove the stopper at the bottom of your toilet bowl.

Step 6: Unscrew the Plastic Nut

You are now good to go — simply unscrew the plastic nut that locks the toilet bowl in place. It will take a pair of locking pliers and an adjustable wrench to turn the nut clockwise and hold it in place while you turn it clockwise. You will have to keep turning the nut clockwise until you find that it’s no longer attached to your toilet.

If the nut is new, removing the lock nut from the toilet tank will be easy. When you try to pry the big nut that fits into the tank of your toilet, take care to do it slowly and gently. It’s a very strong plastic nut; if you overforce it, it will break.

How to Loosen Tight Plastic Lock Nuts 

Using pliers or a spud wrench, you can loosen the nut that secures the toilet tank. After you have cut off the water supply and emptied out the tank, you will have to get a couple of tools to remove the lock nut. It is easy to find the hose connecting to a toilet’s water supply. Simply follow the hose that goes from the toilet to the water supply valve, which is located on the wall.

After you find the water supply valve, turn the water handle all the way to the right to stop the water flow. Take out the lid of the toilet tank and carefully set it aside. To start draining the water from the toilet tank, just rely on the handle to force the water into the toilet. Continue to do this until the tank has completely dried out. If there is some water in the bottom of the toilet tank, you can use a clean, dry towel to soak up the water.

Take another towel and put it on the floor underneath the toilet tank. You will need some pliers, an adjustable wrench, and a screwdriver to loosen the lock nuts on your toilet tank. There is a plastic pipe that connects the top of the tank to the water supply hose. You must unscrew this pipe to get access to the nut. Removing the plastic piece that connects the water supply hose to the toilet tank is as easy as removing a pair of pliers or using a spud wrench.

Once you have disconnected the water supply hose, find the lock nut that holds the toilet tank in place. It should be right above the area where the toilet is connected to the tank. If you see a large lock nut, you are doing the job that you should be doing. It is a fairly large plastic nut that secures the hose to the toilet tank. You will need a spud wrench or pliers (designed to remove a hex nut), or an adjustable wrench. Now turn the plastic nut counterclockwise to loosen the lock nut that secures the tank.

How To Remove A Stuck Locknut

If you have completed all the steps in the guide and the locknut still won’t let you remove it, there are a few things you can try. Removing lock nuts from plastic parts is tricky because they can break easily. Here are a few things to try:

Try Locking Pliers

If the locknut is still tightly secured, try using a pair of pliers to try and unscrew it. You will need a pair of locking pliers to do this.

Locking Pliers

Put the pliers on the narrowest setting that will fit snugly around the lock nut. Turn them counterclockwise. Ensure the pliers fit snugly around the lock nut before attempting to remove it. Come from either the top or bottom of the nut and do not come from the side. Use both hands to grip the pliers, then turn the pliers counterclockwise to spin the lock nut.

You can remove a very difficult lock nut by using a plumber’s grease or other similar liquid. Apply some plumber’s grease to the lock nut and allow it to sit for 10 to 15 minutes. You can then try rotating the nut to remove the nut. If you find the lock nut to be stubborn, try to remove it by turning it counterclockwise with a pair of pliers.

Try Using A Hot Rag To Lubricate The Nut

If you cannot remove the lock nut, lubricate it by placing a hot rag over the nut with a hot wet towel or rag. You’ll need a hot rag or towel and a wrench that can change the locking mechanism of the plastic nut.

You can also try to wring a hot rag or towel that has been submerged in hot water to get some steam from it. Hold the hot rag or towel against the nut for a few minutes to cause the nut to lubricate. The lubricant in the lock nut will help you to quickly and easily remove it. If you have heated the lock nut, use your basin wrench, strap wrench, or pipe wrench to try to turn it around. Do it by turning the nut counterclockwise.

Angle Grinder

If all other methods of removing the plastic don’t work, you can use an angle grinder to shave a hole through the plastic. Unfortunately, this method will not always work because most angle grinders will not fit inside a small tank.

For this method, you’ll need:

  • Gloves
  • Flathead screwdriver
  • Angle grinder
  • Safety goggles

Wear safety gear and use the angle grinder carefully to cut through the plastic nut. If you are cutting through the nut, be careful not to go too deep or damage any other parts. Once you have cut through the nut, use a flat-head screwdriver to drive the two ends of the nut apart. Once you have done that, carefully hold the lock nut in place by pressing down on it and removing it with your hands.

How To Loosen Faucet Mounting Nuts

It is similar to removing the washer from the bottom of a toilet tank. For any project that involves taking apart a faucet or toilet, remember to shut off the water supply to that particular faucet.

Use channel-type pliers to grasp the nut holding the faucet body. Rotate the nut counterclockwise until it pops out. There may be a spout-mounting nut that allows you to turn the nut counterclockwise to remove the nut. If there is one on a spout, use the same techniques that you would use to remove a lock nut from a toilet tank.

Some nuts on some faucets are difficult to remove. Certain shapes prevent a simple basin wrench from removing it. Also, it may be difficult to remove plastic nuts from faucets. However, you can try to use a basin wrench to help you do that. Position the wrench jaws so that they will face down toward the nut to allow you to turn it counterclockwise. 


How Do You Get Plastic Nuts Off A Faucet?

Try a sharp hammer and a flat-head screwdriver to loosen the nut’s plastic nibs and a hammer to pound it down. Tap the head of the screwdriver to try and break loosen the nut. Some people also try heating the nut with a hairdryer or by using a calcium dissolver. If you dry the nut with a hairdryer, it will loosen the nut, and you will be able to remove it more easily. 

Also, allowing the nut to sit a few minutes to loosen will help if you use calcium dissolved in water – let it sit for a few minutes before trying to loosen the nut. You can also try using a lubricant such as WD-40 to help loosen the nut. If you decide to use a lubricant, avoid using heat to melt the lubricant. Many lubricants are very flammable.

How do you get rusted plastic bolts off a toilet seat?

When rusted bolts are found, spray penetrating oil on them. Give the oil at least 15 minutes to penetrate the bolts. Remove the plastic caps that cover the bolts on your toilet seats if your toilet seat allows you to do this. Spray rusted bolts with this penetrating oil and give it at least 15 minutes to soak in.

How do you loosen tight plastic bolts?

To loosen tight plastic bolts, follow these steps:

  • Pull out any fasteners stuck in the bolt that holds the lock nut in place.
  • Rigidly hold the lock nut with a pair of pliers or a wrench in your hand, and turn it counterclockwise for about an eighth of a turn. 
  • Grip the lock nut that allows you to loosen it by placing your thumb and forefinger in the groove and then unscrew it completely.

How do you loosen a plastic wing nut?

Place the tip of a flat-head screwdriver on the right side of one of the wings to force the wing nut to spin counterclockwise. Tap the end of the screwdriver until it causes the wing nut to turn counterclockwise. When it is turning counterclockwise, twist it firmly to remove the nut. 

How do you remove toilet flange bolts?

Remove the screw caps from the toilet by turning the toilet bowl 180 degrees and pressing down hard on the bottom of the toilet. Remove the nuts that were in the floor bolts with a wrench that you can easily adjust and set them aside to be reused later. The bottom of the toilet bowl is sealed to the flange with a sealing ring made from thick, white plastic. Gently rock the toilet bowl on its side to loosen this seal.

What size is the nut on a toilet?

The most commonly used supply tube for a valve is a 3/8-inch hexagonal compression nut.

Wrapping Up

Try using a plumber’s grease to grease a lock nut that is difficult to loosen. Apply some plumbers grease to the nut and let it sit for 10 to 15 minutes. Once that has sat, you should be able to push it out by hand or with pliers. Overall, any of the above methods should let you easily remove a plastic nut from your toilet tank. If nothing seems to work, it might be time to call in a professional plumber.

Smith Edwards

Smith Edwards is a licensed plumber and writer with over a decade of hands-on construction and home improvement experience and has been providing home improvement advice for over 12 years.

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