Pump problem I can't figure out, but I don't know very much. Pump is almost 3 yrs old. It seems to get weak the longer it's running. Doesn't matter at what speed I run it. If it's set to run at 3450 RPM, after a few hours it feels more like it used to at 2700 RPM coming out of the returns. 2450 feels more like 1700, 1500 feels like it isn't even on. The flow eventually becomes low enough that my SWG shuts off even when it's set to 2450 RPM because it can't detect enough flow. The pump still sounds like it's operating at the set speed however, not a lower speed. Nothing is clogged, filter presser remains steady. Do these pumps only last less than 3 years? Is this a common problem? Is there a fix for it? What can I check? Thanks for any advice.