How to Remove Plastic Nut from Toilet Tank | Easy Ways to Do

Toilet tanks are made of several movable and immovable parts, some of which are fastened with couplers or plastic nuts. The nut is generally used to secure the fill valve and is located slightly above the coupling connecting the tank to the water supply line. Removing this fastener without creating a mess is a challenge but still doable if you follow our easy guide below.

To remove the plastic nut from the toilet tank, you must first empty the tank. Remove the coupling connecting the water supply hose at the bottom of the tank to expose the plastic nut. Use a hex wrench and some plumber’s grease to unfasten and remove the nut.

Tools Required to Remove Plastic Nut From Toilet Tank

Removing the fill valve nut seems complicated, mostly because you’ll have to remove the tank to access it. However, all you have to do is follow the steps below to remove it successfully. Before getting started, make sure to gather the tools and supplies below.

  • Hex wrench
  • Pliers 
  • Adjustable wrench 
  • Hose 
  • Rag
  • Bucket 
  • Penetrating oil (optional)

How to Remove Plastic Nut from Toilet Tank in 5 Easy Steps

Have you gathered everything above? It’s time to get your hands dirty. You can remove the nut without help if your toilet tank is made of plastic. If your toilet has a ceramic tank, you may need a helper to aid you in lifting it.

1. Shut off the water 

Removing the plastic nut involves accessing it from underneath. This involves disconnecting the water inlet line and lifting the tank from its place to expose and remove the nut.

It goes without saying that disconnecting a water line without turning off the water will create a huge mess, so locate the toilet’s shut-off valve, which should be somewhere around your toilet. 

If you can’t find it (some toilets don’t have a shut-off valve installed), locate the general shut-off valve in your bathroom or turn off the water from the main valve located in the basement or outside your house.

2. Remove the lid

All toilet tanks have a removable lid that prevents debris from falling into the tank. This lid isn’t generally fixed with anything, so all you have to do is lift it. Plastic tanks have lightweight lids that are a cinch to remove. However, ceramic lids are generally heavy, so you might want to pay extra attention or ask a helper to give you a hand.

3. Empty the tank

At this stage, you must empty the tank so that you can disconnect the water line and lift it from the bowl. Flush the toilet first – this will help you get rid of most water. Since the water is shut off, the tank won’t refill.

Once flushed, use a rag to mop all remaining water into a bucket. Remove all the water, then dry the tank’s interior with a clean cloth, especially around the flush valve.

4. Disconnect the water supply hose 

Place a towel or rag on the floor, then unscrew the coupling nut holding the water supply hose in place. You can do that with an adjustable wrench or a pair of pliers. 

Most modern tanks come with plastic couplers that don’t rust. However, if your toilet has a metal coupler that is rusted, you can use some penetrating oil and apply torque until you feel the coupler coming loose. You can then unfasten it by hand.

5. Remove the nut

Once you’ve disconnected the water supply hose, locate the fill valve nut right above the coupling. Turn it counterclockwise with a hex wrench to loosen it, then unfasten by hand until it comes off. You can now replace the fill valve if it’s broken or install a new plastic nut.

How To Remove Stuck Plastic Lock Nut On Toilet

While the steps above tell you how to remove a plastic lock nut in general, you may find that the nut is stuck. What now? Luckily, there are still ways to remove it, even if they require a bit more patience and elbow grease.

1. Access the nut

Follow all steps above until you locate the nut above the coupler. Remember to remove all the water from the tank and dry it thoroughly to prevent messes.

2. Lubricate the nut

The only way to remove a stuck lock nut without damaging it or the tank is by lubricating it. You can use penetrating oil or plumber’s grease – penetrating oil is your best bet. Spray it onto the nut and wait for a few minutes until it leaks through the threads.

3. Remove the nut

Grab the nut with a hex wrench and turn counterclockwise. Apply torque until you feel the fastener coming loose. Continue turning until it becomes easy to unfasten; then, you can continue turning by hand until it comes off completely.

How to Prevent Plastic Nuts from Getting Stuck

There are few things you can do to prevent toilet plastic nuts from getting stuck. While they aren’t affected by rust and corrosion in the way metal fasteners are, rust can form on the bolts and get the nut stuck. One way to prevent this is by using a lot of plumber’s grease to lubricate the connection.

You can also protect the nut with a thin coat of nail polish or use a nut cap to keep it in good conditions for longer.

How to Remove Spud Nut From Toilet Tank

The toilet spud nut is installed between the toilet seat and the tank, where the tank drains into the bowl. Its role is to seal the connection and prevent leaks when you’re flushing. Removing this nut still requires you to empty and lift the tank.

1. Gather the necessary tools and supplies 

You will need: 

  • Adjustable wrench
  • Screwdriver 
  • Rags 
  • Bucket 
  • Rubber gloves 

2. Empty and remove the tank 

Follow the steps above to drain the water from the tank. Use a rag to dry out the tank, then unfasten the couplers and lift them from the seat.

3. Remove the overflow nut

The toilet stud is held in place by three bolts fastened from inside the tank. However, you won’t be able to remove the gasket without removing the overflow nut first.

This nut is fastened above the gasket and, as its name suggests, prevents the tank from overflowing as you flush.

Use an adjustable wrench or a pair of pliers to grab the nut and turn it counterclockwise. If your toilet is older, you may have to apply quite a bit of torque to get it to budge.

4. Remove the spud bolts

Spud gaskets work on compression; as you tighten the screw, the gasket’s stem gets pushed down the holes at the bottom of the tank, creating a watertight seal. Because the rubber has an excellent grip on the bolts, they aren’t fastened with nuts.

Use a screwdriver to unfasten and remove each of the three screws holding the spud in place, then take off the rubber gasket.

How to Remove Mounting Nut From Toilet Tank

The toilet tank mounting nuts are the nuts holding the tank fixed onto the toilet seat. You can remove them easily with a wrench or a pair of pliers.

1. Turn off the water and empty the tank

Removing the mounting nut from the toilet tank means the tank is no longer held securely onto the seat. To prevent messes, empty the tank by turning off the water supply. Flush the toilet to empty the tank and mop out the excess water with a sponge.

2. Locate the mounting nuts

The toilet tank mounting nuts are generally located under the toilet seat, right beneath the tank. They secure the bolts that keep the tank in place. Some toilets have three bolts, whereas some models only have two.

3. Unfasten the nuts

Use an adjustable wrench or a pair of pliers to unfasten each nut and remove it. You can then use a screwdriver to drive the screws out of their holes.

Because these nuts and bolts are made of metal, rust and corrosion can get the nuts stuck. If this happens, spray some penetrating oil onto each nut and wait for 10-15 minutes for it to lubricate the threads.

Grab the nut with a pair of pliers and turn counterclockwise. The nut may not budge immediately, and you may have to apply a lot of torque. Don’t give up and keep turning until the nut gets loose and you can unfasten it.


Knowing how to remove the plastic nut from your toilet tank is important if you don’t want to call in a plumber each time you detect a leak. The process isn’t complicated, especially if you follow the easy steps above. 

A few things to remember is that you should always turn off the water supply and empty the tank each time you have to remove the nuts under it or replace any internal component. Penetrating oil can help you remove stuck nuts, but don’t forget to apply some plumber’s grease on the new couplers to prevent them from getting stuck.

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