How do I fix a leaking pool skimmer?

Replace the gasket. The rubber seal between the skimmer and pool wall dries out or cracks. Turn off the pump, remove the basket, unscrew the faceplate, pull off the old gasket, clean the groove, install a new one, and tighten the faceplate evenly. If the leak persists, you may have a crack in the skimmer housing or pipe joint.