How to Repair Leaky Plastic Fittings

Use a pipe cutter to cut through the CPVC pipes.

Water supply pipes can be made of either CPVC or copper. The CPVC pipes are joined together with plastic couplings, or fittings, primer and PVC cement (glue). If the joint begins to leak, silicone sealant can be a quick and somewhat temporary fix to the problem. The better long-term solution is to replace the joint. This is a fairly simple step-by-step process to complete for anyone with DIY experience, and the job is not time consuming.

Things You'll Need

• Tape measure
• Felt tip pen
• CPVC pipe
• Pipe cutter
• PVC primer
• CPVC straight couplings
• Replacement coupling
• PVC glue

Instructions

1. Turn the water off at the main shut-off valve, and drain the pipes by turning on the lowest faucet in the house.

2. Mark the two pipes coming into the joint four inches away on each side with a felt tip pen. This is to ensure that there is room to install a new coupling and pipes.

3. Measure from one mark to the center of the coupling, and then measure from the other mark to the coupling's center. Cut two new pieces of CPVC pipe to these lengths.

4. Cut through the existing pipes at each mark using a pipe cutter. Remove the old leaky coupling. Apply PVC primer to the ends of the existing pipes, as well as all four ends of the two new pipes. Prime the insides of the two new straight couplings. Also prime the inside of a replacement coupling for the one that was leaking -- this might be a 30-, 45-, 60- or 90-degree coupling. Wait 30 seconds for the primer to dry.

5. Apply PVC glue to the existing pipe ends, and the insides of the two straight couplings. Then glue one end of both pieces of new pipe. Push the couplings into the ends of the existing pipes, and the new pieces of pipe into the other ends of the couplings. Hold in place for 30 seconds.

6. Glue the other ends of the new pieces of pipe, and both inside ends of the replacement coupling. Push the pipe ends into each end of the replacement coupling, and hold in place for 30 seconds. Turn the water back on.

Tips & Warnings

• If replacing a plastic fitting on a PVC sewer line, the process is the same, but a hacksaw is required to cut the pipes. Also, the water does not need to be turned off.

References

• "Home Improvement 1-2-3"; Benjamin W. Allen, Christopher Cavanaugh; 1995