To replace toilet supply lines yourself, you’ll need a trip to the hardware store with about $50-$150 in your wallet and less than 60 minutes of labor.

Doesn’t sound so bad, right? I’m going to tell you everything else you need, including step-by-step instructions.

Table of Contents

Getting Started

You’ll need the following to get this project moving forward:

Sponge
Bucket
2 adjustable wrenches
WD-40 lubricant (only if needed)
Tape measure
Braded stainless-steel supply line

replace toilet supply line - braided stainless steel supply line for toilet — You can find a flexible, braided stainless steel supply line for your toilet at any hardware store or online. The cost is about $5 to $15. Make sure to get one that fits (take your old line into the hardware store with you).

How to Replace Toilet Supply Line

The toilet’s water supply line is one of the most common causes of leaks in your home. It’s an area of our plumbing that we rarely look at until it’s too late.

Unfortunately, the thin tubing that connects the cold-water supply line to the toilet can corrode and leak. If you find wet flooring underneath your toilet, check the supply line and water shutoff valve carefully. You will need to purchase a braided stainless-steel supply line to replace it.

As you follow my instructions, don’t forget to click on any of the resources listed further down the page to get more details on related projects.

1. Close the Shutoff Valve

Always begin a job on a water-using fixture (like a toilet or dishwasher) by turning off the shut off valve.
If you don’t see a shut off valve for that specific fixture, you’ll need to turn off the main water shut off valve (probably in your basement, nex to the water meter).

replace toilet supply line - turn off shutoff valve — Begin by shutting off the water supply to the toilet.

2. Empty the Toilet Tank

Flush the toilet; the purpose of this is to get the tank empty of water before you begin work.
Because you’ve turned off the water supply, you’ll notice that no water goes back into the tank or toilet bowl. But there will be some water left over in the bowl.
Use a sponge and bucket to remove the remaining water (in tank and bowl).

replace toilet supply line - remove water with sponge — Use your sponge and bucket to remove any excess water in the toilet tank and toilet bowl.

3. Remove the Supply Line

Caution: The following steps are for removing the supply line tubing from the shutoff valve and tank. You are not to remove the shutoff valve itself.
Place the bucket below the shutoff valve where you’ll be working. This will catch any water that drips out.
Lock one of the adjustable wrenches onto the shutoff valve to keep it from moving.
Use the other wrench to loosen the compression nut that holds it in place.
Be gentle but firm. The valve can break easily if you use too much force.
If it seems too tight to loosen, use your WD-40 oil or a similar type of lubricant. Spray onto the compression nut and wait 15-30 seconds. Then try again, gently but firmly.
Once the supply line has been disconnected from the valve, disconnect the top end from below the toilet tank. This will be much easier because it can sometimes be loosened and removed by hand.

replace toilet supply line - stabilize and disconnect — The important part to remember in this step is to stabilize the water shutoff valve with one wrench, while using the other to remove the supply line above it.

4. Measure & Fit

This is the fun part for those who like math (I’m not one of them!).
Measure the distance from the shutoff valve to the area just under the tank where the water supply line feeds in.
When you purchase your supply line, use this distance (but add an inch or two for slack).
Now bring the old parts (supply line and connectors) to the hardware store so you can purchase a new one that matches and fits.

replace toilet supply line - measure distance from shutoff valve to tank — Measure the distance from the toilet shutoff valve to the bottom of the tank, then add a couple of inches for slack. That measurement is the length you’ll want to purchase for your new flexible, braided-steel supply line.

5. Connect Flexible Supply Line

Attach the new tubing to the toilet tank and water supply areas.
Connect the supply line by hand, gently but firmly.
Use the same method you did before with the adjustable wrenches. However, this time, you will be connecting and tightening it (while keeping the shutoff valve stable and secure).
Turn on the water and check for leaks. If none, you’re done.
If it’s leaking, take a look at all of your connections and give them a final quarter turn.

replace toilet supply line - connect to valve and tank — Your final step is to connect the new supply line to your water shutoff valve and the bottom of the toilet tank (the fill valve).

Final Thoughts

That wasn’t so bad, was it? All you’re really doing is turning off the water to the toilet, emptying out any remaining water, removing the supply line, and replacing it with a new supply line. That’s it. No soldering. No pipe fitting. Just remove and replace.

Call 1-Tom-Plumber

Don’t hesitate to contact us here or call us at 1-Tom-Plumber (1-866-758-6237) if you have a toilet running intermittently.

1-Tom-Plumber’s certified team of plumbers and drain technicians respond immediately to any emergency plumbing, drain cleaning, or water damage problem. We also handle the excavation of underground water lines and sewer main lines. Our immediate-response team is available every day and night of the year, even on holidays.

Need To Replace A Toilet Supply Line? (Here’s How!)

Getting Started