Can shaft seal failure look like a suction side air leak?

RickRoss

New member
Apr 26, 2018
3
Nashville, TN
I have a spillway pump for my negative edge pool, and although the pump is moving water, the amount of air in the filter basket suggests a suction side air leak. I have done what I can to check the filter basket lid, the pump input, the drain valves and all the visible pvc joints leading into the pump. As far as I can tell, none of these is responsible for the air leak.

Is it possible for a failing pump shaft seal near the impeller to let air into the running pump system? Could this actually cause the same symptoms as a suction side air leak in the input pipes? Before I call professionals to see if somehow the underground pipes from the spillway basin to the pump have developed an air leak I would like to rule out another potential source of air in the filter basket.

Thanks in advance,
Rick
 

RickRoss

New member
Apr 26, 2018
3
Nashville, TN
Happily, I located the source of the problem elsewhere, and it was easy to fix. It turns out there was some serious obstruction in a backflow preventer on the intake end of the pipe in the spillway basin. The obstruction was not externally visible, but when I took the device apart to check it I found all manner of crud had been sucked in. Now to find a pond strainer large enough to prevent this happening again!

It was really interesting that the effect of the intake obstruction looked just like a suction-side air leak, but once the obstruction was cleared there was no air in the pump basket whatsoever. Live and learn.
 
Last edited: