Possible pump motor bearing failure?

[kballard72]

The impeller wear ring was slightly etched in comparison to the new. after seeing the new, that was probably normal wear. The impeller itself had no damage and kept it as a backup.

Diffuser was not replaced. It also would never be allowed to spin as the tristar has two screws holding it in place

Occasional bubbles at the returns, some air can be let off from the filter (though not seen in the basket).

Looked all on the strainer (suction) side and can spot no cracks..

[PoolDoc]

Sounds like you may need to exorcise the pump pixie!

[kballard72]

It has crossed my mind to have the top two feet jackhammered, back filled, and go back to mowing a lawn....

[mas985]

Ok, I am starting to run out of ideas but I am not willing to give up yet. If you have a suction gauge, it might be helpful to find out what is happening on the suction side of the pump during this period of pressure drop. If the suction increases during this period, it could be cavitation that we are hearing and then we just need to figure out what is causing the suction to increase. If the suction decreases, it could mean that there is something occurring inside the pump besides cavitation. Most gauges with 1/4" fitting will fit the suction side drain plug.

If you want to give up, I completely understand. These types of problems can be very frustrating.

[kballard72]

No suction gauge.

I don't know if this observation would be comparable or just convolute the issue. I have a navigator vac that until this problem, for it to get into the flow spec per the hayward gauge: I would turn both skimmers off and drain valve 1/3 off, so the navigator would have max flow.

With this problem occurring to see if I could get the thing to sweep at all, with the drain almost closed off, skimmers completely shut down, could only get to low end of the hayward flow gauge...

Will see if I can locate an actual suction gauge.

[mas985]

Yes that can be very relevant. Do you have the same problem without the cleaner and with the skimmers and main drain fully open?

Reducing the flow too much to the pump can be problematic.

[kballard72]

Yes that can be very relevant. Do you have the same problem without the cleaner and with the skimmers and main drain fully open?

Reducing the flow too much to the pump can be problematic.

What I am mean is that under normal circumstances, per the builder, was to turn the skimmers off when vacuming.. That always got the flow gauge for the vac to the low end. For 3 years. Just tweaking the drain a little, not all the way to a 3rd would get it to the high side of the gauge...

All I am saying is that since this problem started occurring, if i hook the gauge up to the vacuum port, skimmers closed and the drain almost completely shut off will get it the gauge up to the low/mid point...

[PoolDoc]

Will see if I can locate an actual suction gauge.

Dixon Valve GL105 2" Steel Lower Mount Compound Vacuum Gauge @ Amazon

2 days, if you have Amazon Prime. You may also be able to adapt an automotive vac gauge, available at Autozone or some such.