A sink pipe, according to Simple Home Repairs, separates into three sections connected by joints: two straight sections connected to the sink and to the wall, and a P-trap connecting the two. The P-trap keeps sewage from backing up into the sink. Leaks can occur at the joints or in the pipes.
To prevent flooding, shut off the water supply leading to the sink using the valve located near the underside. Tighten it as much as you can by hand. Feel the areas around the joints first. If they feel moist or wet, you've found your leak. Don't neglect the pipe sections, because they can corrode or wear down.
Locating the Leak
A sink pipe, according to Simple Home Repairs, separates into three sections connected by joints: two straight sections connected to the sink and to the wall, and a P-trap connecting the two. The P-trap keeps sewage from backing up into the sink. Leaks can occur at the joints or in the pipes.
To prevent flooding, shut off the water supply leading to the sink using the valve located near the underside. Tighten it as much as you can by hand. Feel the areas around the joints first. If they feel moist or wet, you've found your leak. Don't neglect the pipe sections, because they can corrode or wear down.
Disassembling the Pipes
Use a pair of pliers or a wrench to remove the nut connecting the drain to the bottom of the sink. According to Lowe's, always use padding between the tool and the metal couplings to avoid damage to the couplings. Damage to these couplings can increase the likelihood of leaks because they won't hold pipes together securely. Place a bucket or other container under the P-trap, then remove the wall segment and the P-trap. Take measurements of your pipes' dimensions: circumference, diameter and length of each segment. When you buy new pipe, cut the new sections to the measurements of your old sections.
Replacing Pipes
The material with which you can replace your pipes varies. According to NSF Consumer Information, most homes use copper for plumbing. If your water has a pH below 6.5, copper can potentially leach into your water and cause heavy metal poisoning. You can replace copper plumbing with PVC pipes to offset this risk.
Use a hacksaw to cut your new pipe lengths to their proper dimensions. Replace the plumbing in the opposite order of removal: wall piece first, then the drain, then the P-trap. Tighten all the joints, wipe down the pipes and restore the sink's water access. Turn on the faucet and let it run for 30 seconds to watch for a leak.
