APO sucking air?

[Chris A]

I have a 98 CDS I recently put back into service, I haven't used the pump out much, but recently, after cleaning the screens on the box, I noticed it was sucking air when the machine was running. Also, I notice after shutting the APO off, water will continue to flow. I assume there's a ball valve somewhere? I just put a garden hose shut off on the outlet for now, but would like to figure this out. Thanks everybody, Chris

 

[KevinD]

There should be a check valve between the pump and outlet, probably got something stuck in it.