How to Repair a Leaking Compression Fitting

What You'll Need
Pipe or tubing cutter
2 adjustable wrenches
Compression nut
Pipe joint compound

If you have a compression fitting under your sink that is leaking, fixing it requires a little more than a wrench. Still, repairing the leaky compression fitting is not that hard, and this guide will show you how.

Step 1 - Turn Off Water

Turn off water to sink by closing the inlet vale or shutting of water main.

Step 2 - Cut Off Old Ferrule

Unscrew the compression nut. Then, cut the pipe just behind the ferrule with the cutter. The ferrule is the component farthest from the tubing or pipe end.

Step 3 - Install New Ferrule

Slide on the new ferrule. Then, apply joint compound to the ferrule and pipe. Then, slide pipe into the adapter all the way until you can not push it in anymore.

Step 4 - Install Compression Nut

Place the compression nut on the tube and press up against the back of the ferrule. Then, push the ferrule and and compression nut all the way along the pipe until they are up against the valve or fitting hub. Use your fingers to twist the compression nut onto the threaded end. Then, tighten the nut with one wrench while holding the valve or fitting in place with the other. Be careful not to over-tighten.

Step 5 - Turn On Water

Turn the water back on at the sink inlet valve or water main. Test for leaks. If there are leaks, tighten the compression nut a little more.