How to Repair a Leaking Sink Shut-Off Valve

The shut-off valve under sinks can go unattended for years without giving any problems, but once they start leaking, it can lead to a mess. Minor ignored leaks can waste up to 3 gallons of water every day and can also leads to permanent water stains under your sink. Calling a plumber can be expensive. So to save your valuable time, money and water, here are a few easy steps to repair a leaking sink shut-off valve.

Step 1 – Safeguard the Parts

Wrap a masking tape around the jaw of your slip-joint pliers to avoid scratches and damages on the soft metal parts of the leaking shut-off valve. 

Using the pliers to grasp the nut positioned behind the shut off valve handle and turn it slightly clockwise. Watch carefully to see if the dripping has stopped, or even reduced to check if this simple repair stops the drip. If the leaking has reduced, then turn the nut a little more. If the leaking does not stop, then proceed to the next step. 

Step 2 – Turn Off the Water Supply

Turn off the main water supply to the sink you're working on and drain out the pipes completely. Place a small container under the valve to catch the small amount of water still left within. 

Step 3 – Dismantle the Screws

Remove the screw from the shut off valve handle by using a simple screwdriver in order to dismantle it from the sink. It is not necessary to remove it from the supply line. After loosening the nut, pull out the threaded valve stem. Keep a careful note of the position and size of the washers. 

Step 4 – Clean and Replace Washers

You can either replace these washers with new ones of the same size, or just clean them. Be sure to use a fresh rag to remove all the unwanted and patchy mineral deposits. Clean them gently without scratching or tearing them. Once they are clean, they become more flexible. 

Step 5 – Reassemble

Assemble the pieces back together, avoiding the use of any plumbing lubricants. These lubricants could stick up the valve components together, making it difficult for future repairs. Turn on the water supply to the sink. As the line gets filled, watch out for leaks and then check if the hut-off valve will have to be replaced.

A leaking shut-off valve is extremely easy to replace. All you need to be careful about is that you must be able to find an identical shut-off valve to the old one with regards to the type, size and thread. While repairing the leaking sink shut-off valve, it is essential to bear two things in mind. Always shut the drain before attempting any repair to prevent parts from slipping into the drain and pay attention to the order of each dismantled part to help in faster reassembling of parts.