Possible pump motor bearing failure?

[mas985]

Unless you got that vacuum gauge.

BTW, does the flow rate out of the returns decrease or increase when the pressure drops?

[kballard72]

it definitely decreases. as well as the water feature, which is simply two returns on the sun deck that point straight up.. they drop from 2 feet high down to 6 inches....

For that wear ring to have carved away an 1/8" of plastic off the inside of the diffuser, is that a normal amount of wear?

Well clearly there were items worn out and they have all been redone, and seems to be casualty symptoms of something else going on. Impeller, wear ring, and now diffuser. All of which were visibly worn with the diffuser seeming to be abnormally chewed up. Either way all internal parts except the motor are shiny and new.

The odd thing is the split second change, as if something "gives" like suddenly the pressure is just gone... Its not gradual... after being off for awhile you can turn it on, all will be well, than bang, pressure dives and noise starts.

The noise which sounds like rocks clattering, is what I have read to be the sound of cavitation. So that may just be s symptom of the pressure drop and not the cause of it. One way I have found to make the noise stop is restrict the returns to cause the pressure to build up some. I dont leave it like that, just something I noticed.

[BigDave]

Is it possible that you have some flex PVC or other soft wall piping that may be collapsing under sufficient vacuum and time.

[kballard72]

No flexible piping in the system. Oh I wish it were the obvious solution. dry skimmer, etc.... covered already though....

[mas985]

The noise which sounds like rocks clattering, is what I have read to be the sound of cavitation. So that may just be s symptom of the pressure drop and not the cause of it. One way I have found to make the noise stop is restrict the returns to cause the pressure to build up some. I dont leave it like that, just something I noticed.

Those are the symptoms of cavitation and if a line is collapsing as Dave suggests or there is some sort of periodic blockage, increasing the return head would allow it to expand again (reduce the suction head). A suction gauge would help to confirm that.

Also, the video does not show the suction side plumbing very well. Do you have a check valve anywhere? Sometimes the flappers can break and cause similar symptoms.

[kballard72]

There is one check valve side after the filter and before the 8 tab chlrine feeder...

Ok... Towel, thrown... calling service....

[PoolDoc]

For my sake, and especially, for Mark -- when you find out what the problem actually was, please let us know.

[kballard72]

Yeah, all the input insight is appreciated.....

Extremely frustrated, as I've rebuilt engines, worked on 100,000 dollar laser medical printers.... and a freaking pool pump and some plumbing has me stumped....

It's gonna be a piece of dang mulch flying up and getting stuck in one of the T connectors and sinks back down whenever the pump shuts off, thats causing turbulance in the flow.... Something I cant see without cutting plumbing... And still tempted to do since one of the valve handles snapped off today (while opening it for the 100th time this week) . cheap junky 8 dollar ball valves.... But the grand wizards that built the thing butted all the connections in such a manner... I have to cut out all 4 valves on the suction side and redo the whole darn run...


There is not enough pipe space to splice....full redo...

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