How to Repair a Leaking Bathroom Shower Faucet

A leaky bathroom shower faucet is annoying, wasteful and leads to higher water bills. It’s usually caused by worn-out or damaged parts in the faucet, often the washer on the shower stem.

It's a good idea to do a full replacement of all gaskets and seals when you do a shower faucet repair. If this is your first time repairing a particular faucet, you may have to find out exactly how many and what types of seals and washers you need. Ask the professionals at the hardware store to help you find the necessary parts.

Step 1 - Shut Off the Water

Shut off the water heater in your house, usually located in the basement or garage. If there is a laundry tub in the basement or a basement bathroom, open the sink faucet to drain the water from the system.

TIP: DoItYourself.com’s plumbing consultant Mark Vander Sande suggests, “There may be shut off valves behind the bathtub. If there is an access panel, check here first.” Return to your shower faucet and turn it on to release any stored up water.

Step 2 - Disassemble the Faucet

There are two main types of shower faucets: one-handle and two-handle. If you have a two-handle system, then you have to remove and replace both valves. First, unscrew the valves and remove the knobs or handles. You may need a handle puller depending on the age of the faucet. Carefully remove the escutcheon that covers the hole the valve sits in and set it aside

There will be a nut, called the “packing nut,” here. Don’t be tempted to loosen or remove it. Instead, you must remove the whole hexagonal part. This is the actual valve stem. You may need a set of valve stem sockets. Find the right size for the solid brass valve stem and use a pair of channel lock pliers to unscrew it. Keep track of how the shower stem is assembled.

Step 3 - Replace Bad Washer

There is one washer at the end of the valve stem. You can either remove the washer and take it to the hardware store and get the same one or buy an assortment of washers and find one that fits.

TIP: Mark adds, “Depending on the age of the faucet, where the washer attaches to the stem there’s a brass holder that holds the washer to the valve stem with the screw. If the holder is broken or damaged, take the stem to a hardware store and get a new stem. If they don’t have a matching stem, there is a repair washer that has a brass holder and a screw that attaches on top of the existing stem. It is not recommended you use this last resort option, but it may get you through for a while. Find a new stem and replace the entire stem as soon as you can.”

Step 4 - Check the Valve Stem Seat

It’s important to check the seat inside the faucet where the valve stem goes. If you look inside the faucet body where you just removed the valve stem, you will see the seats. Use a flashlight. The seat is the brass part that the washer sits on when the faucet is off. If you change the washers on the faucet stem and the seat is damaged, it will continue to leak.

Step 5 - Remove the Seat and Replace It

Buy a seat removal tool or a seat wrench at the hardware store. Insert the tool so when it fits inside the seat it’s tight. Use a channel lock pliers and unscrew the seat. It’s a brass fitting so it shouldn’t be too difficult to remove. Take it to the hardware store and get a replacement and install it with the seat wrench. Tighten it, but do not overtighten.

Step 6 - Grind the Seat Smooth

You can try to grind it smooth. It may get you by for a while, but if the faucet leaks again in the future you may want to consider replacing it. Buy a seat grinding tool at the hardware store.

This tool comes with different size grinders. Install the size that fits into your faucet and follow the directions that come with the tool. The idea is to grind the brass seat smooth so the washer will seal.

Step 7 - Clean and Reassemble the Faucet

Before putting the shower stem back, take the opportunity to clean any gunk from the pipes. Put the shower stem back into the pipe in reverse order from how you took it out. Use some faucet grease and apply it to the faucet stem threads. In order to prevent damage, re-caulk the faucet plate. When completely finished, don't forget to turn your water back on.

Mark Vander Sande, a professional plumber, contributed to this article.