How do I find suction-side air leaks in my pool pump?

Run a garden hose over suspect fittings and joints while the pump is running. If the water seals the leak, the air bubbles in the pump basket disappear—that’s your spot. Start at the pump and work back toward the skimmer, having a helper watch the basket. Common failure points are the pump lid o-ring, drain plug, valve stem seals, and threaded connections before the pump.