The most common leakage problem with swimming pool returns is related to air in pool pump systems. Pool pump lid seals become worn, allowing air to enter the pump and then be sent to the pool. In addition, pool pump fittings on its suction side become loose over time and require re-taping with pipe tape and then retightening. Swimming pool pump drain plugs also work their way loose and require re-taping with pipe tape and subsequent retightening, too.
Above ground swimming pool water return leakage calls for examination of fittings, new pipe tape around fitting threads and then retightening. If your swimming pool stops leaking after dropping below the water return, look for leaks near it. If you have a vinyl liner swimming pool and water is leaking from the return, look for rips, holes or tears, and repair them using a patch kit. Use food-colored water in a syringe and inject it near suspected pool leaks to determine their location.
When a swimming pool's returns are putting air into the pool along with returned water, splits or leaks in water lines are many times at fault. Trace each of the water lines in your swimming pool's filter pump system to locate any air leaks in those lines. If you have a water return line itself with an air or water leak, you'll need to repair or replace the line. Pool water return lines are under pressure, so replacing leaky lines is typically required.
Periodically examine all the fittings, seals and plugs on your pool's filter pump for signs of wear. Also take a close look at your swimming pool's returns on occasion to ensure any gaskets, male adapters and other components are in good shape. Air being put into your swimming pool through the water returns is a sure sign of air leaking into your pump system at some point. Regularly examine pool water return lines and pipes to help prevent air or water leakage.