Small air leaks reduce the efficiency of a swimming pool pump and cause an irritating gurgle in a swimming pool, usually at the return jet closest to the equipment. Large amounts of air can bring the system to a complete halt by causing it to lose prime. This will eventually cause the pump to lose any ability to draw water, overheat and melt both PVC fittings connected to the pump, all seals, the impeller and shaft bearings.

Air leaks not associated with a loss of water are located above the water level of the swim pool, somewhere on the suction side of the pump. A loss of water in the pool is generally not related to an air leak.

(right) Air usually indicates old- age in a pump. A pool service trick is to turn the pump on, get the water flow going, and switch off the pump to see where back- pressure forces water out of the system. If you see water spritz out around the lid, the lid either needs tightening, the 'O' ring under the lid needs grease or the male adaptor on the suction side of the pump has vibrated loose.

(left) #Glue, Goop and 2- part epoxy was used in an unsuccessful attempt to repair an air leak in this system; even to gooping up the pressure line between the pump and filter.

Couplers visible on these main drain and skimmer lines confirm the homeowners claim that someone went to the expense of having the main drain and skimmer lines pressure- checked at the suggestion of their pool serviceman.

We simply turned the system 'on', got it running, then turned it 'off' (the 1st and easiest test for airleaks) and saw water spritz out of the hose conncection on the chlorinator. A new $2 feed hose fixed the problem.

(right) Another old service trick is to slather foam shaving cream around a suspected leaky fitting, which works especially well around multifaceted valves and fittings that are so good at eluding other detectors. Where air is drawn in, foam will form a cone pointing directly at the leak.

An air leak at the 4" male adaptor made this above-grade commercial pump almost impossible to prime. Does the foam test work all the time? No trick works all the time, but it works often enough to include a can of shaving cream in a well-fitted tool box.

These are the first tests for finding air leaks. More tests are available in the Pool School PRO CD for all the problems you'll face with your pool.

The homeowner mentioned above spent over $400 with three different contractors to correct a problem that should have taken less than a few minutes to find and a $2 part to repair.

Incompetence is often an asset in pool repair. The guys who missed the problem by focusing on the pressure check made the most money on this job and were scheduled to come back for another $200.

Air leaks are one of hundreds of problems you will eventually face with a pool, all explained on the Pool School PRO CD,