A PVC drain pipe can develop a leak due to a faulty connection or just damage. Most leaks occur over the joint connections, due to inadequate connection or age. The only way to fix the leak is to cut out the bad area and use a replacement part. PVC cement or glue is not a sealant and will not fill in the leak. There are many different types of replacement pieces to choose from made of a range of materials.
Mark where to make cuts around the leaky section of the PVC. This section of pipe should be the same size as your replacement part. It is best to measure twice rather than risk the chance of making an incorrect cut.
Cut the PVC pipe at the marked spots using a handsaw or PVC cable saw. The cable saw is needed for pipes that have no space around them to be cut by a standard saw. A PVC drain pipe is frequently located next to the cold and hot water pipes. Remove any burrs or rough areas on the cut with a utility knife.
Test-fit the replacement part by attaching it to the two cut spots you just made on the PVC drain pipe. The replacement part fits over the old PVC pipe ends. Make any necessary adjustments to ensure a secure fit. Remove the replacement part.
Apply PVC primer to the old PVC pipe ends. Let the PVC primer dry for a minute.
Insert the two PVC pipe ends into the replacement part. Slide the metal clamps into place at the ends of the replacement part. Tighten the clamps. The clamps make a tight connection without the need for PVC cement.