How to Repair a Leaky Compression Valve

What You'll Need
Steel wool
Plastic gloves
Flathead screwdriver
Wrench set
Valve seat

Leaks in compression faucets are often caused by a leaky compression valve. Compression faucets are among the most commonly used faucets in residential plumbing connections. Most compression faucets have different supply lines for hot and cold water. Compression faucets have a conventional internal structure that consists of a washer, o-ring and some other, standard parts that constitute the compression valve fitting. A leaky compression valve can be caused by excessive pressure being induced due to the faulty functioning of any of its vital components. You can use the following guidelines to repair a leaky compression valve.

Step 1—Getting Started

Prepare yourself with a flashlight and a pair of plastic gloves. Older faucets are prone to letting-out short bursts of water upon being disengaged, so wearing some sort of basic eye protection is also recommended. Access the underside of the sink’s plumbing area. Turn-off the water valves on the hot and cold water supply lines. To ensure that water supply has been shut-off, turn-on the faucets and wait for the last few drops to dribble-away.

Step 2—Disengaging Compression Faucet

You need to disengage the water faucet to gain access to its internal parts, i.e. the compression valve fittings. Using the sharp end of the screwdriver, uncork the decorative cap of the faucet handles. Most compression faucets have a central nut, called the packing nut. This nut secures the faucet assembly system. It can be easily disengaged using a wrench. This provides access to the inner stem of the faucet body. When using the wrench to disengage the packing nut, place a soft piece of cloth over the underlying faucet surface to avoid scratching.

Step 3—Disengaging Compression Valve Fittings

The stem contains the compression valve fittings. It is usually recommended that the best way to cure a leaky compression valve is replace the o-ring, washers and valve seat. For this, you need to remove the old compression valve fittings. The o-ring and the washer can be easily disengaged using a screwdriver. The valve seat often needs to be repeatedly tapped against a hard surface to loosen it.

Step 4—Finding Suitable Replacements

For replacing the o-ring and the washer, it is advised that you take the disengaged o-ring and washers to a hardware store to get exact replacements. However, the valve seat is available in standard sizes and finding a precise match is rather easy.

Step 5—Installing Replacements

Installing the o-ring is easy. You can simply place it in its circumference and press upon it. It is recommended that you smooth the surface around the valve seat before installing its replacement. You can use steel wool for this. Rub the seat area with the steel wool until the wool seems to rub against the surface in a smooth fashion. Screw the new valve seat. Replacing the washers is also easy. Simply place the new washer along the edges of the stem and fasten the retaining screw. Remember not to tighten the nut too much or it will induce backflow in the faucet. Now, insert the stem into the faucet body and secure the packing nut. Tighten the packing nut with a wrench.