We have a Jandy pump system that is 2 years old. For the last 2 months the basket at the pump does not fill completely with water when it is turned on (water continues to "swirl" at the top of the lid) and when the pool isn't running the basket's water level will go down to about 1/4 full. Also, when you shut off the pool you can hear a whistle coming out of the basket. We've changed the O ring and that didn't help at all. We suspect there might be a leak in a pipe under our decking that comes from the skimmer to the pump, but our pool water level doesn't drop anymore than usual since it's hot outside. Every time I turn on the pool I have to let air out of the filter cartridge container. We are about to go on vacation and won't be able to do this every time. Can you think of any other reason (besides a pipe leak) for this to occur?