Water lines for sinks in many older homes are copper or chrome plated metal tubing. The lines are difficult to replace because they must be precisely configured to attach in a shutoff valve and a faucet connection in the underside of the sink. Because of this, it’s not unusual for a beginner installer to create a hairline crack in a metallic water line. In a short time, there’s a leak under the sink. It is possible to fix a broken water line by installing a flexible water line in a matter of minutes.
Switch off the shutoff valve in which the lower end of the broken line thrives. Place a 1-gallon bucket under the shutoff valve.
Loosen and detach the fitting in the lower end of the line from the shutoff valve using an adjustable canopy. Reach up behind the sink and detach the fitting in the upper end of the line from the faucet connection. Pull off the water line.
Screw 1 end of a flexible water line to the faucet connection. Tighten the fitting with pliers. Expand the fitting in the lower end of the line on the supply valve and tighten it using the pliers.
Turn on the faucet in the sink. Gradually turn on the supply valve and check for leaks at each end of the new line. Tighten both or one fittings, only as much as necessary to prevent a leak.