Weak pump suction and other issues

[zorks]

Hello all, I recently moved in back to my parents house and was trying to help them fix the pool pump (the pool wasn't really maintained). It is an inground pool system if that makes a difference.

There are a couple of issues withe the pump:
1) Tiny air bubbles showing up in the pump basket
2) The pump basket appears to lose prime (water level drops to maybe half or lower) when I hooked up the pool vacuum
3) Vacuum suction is weak

I have already tried lubing up the pump basket o-ring as well as the one for the union. It removed some of the air bubbles showing up, but not all of them.

I do not believe it is a pool hose issue as I have a vacuum hose that is split into sections. When I plugged in just one section and making sure the hose was fully submerged, the pool pump bucket did not lose prime. But when I tried plugging in 2 or more sections, the pump seemed to have lost some water level.

At this point I am thinking it might be a problem with the pump motor or maybe underground pipes.

The pump is Waterway SMF-110 and the filter is DE filter 570-0036 also by waterway.

Anyways, I wanted to see if you guys would know what is wrong with the pump. Thanks.

 

[JVTrain]

Persistent bubbles in a non-variable speed pump means you have a suction side leak. Air is being drawn into the system on the suction side, somewhere.

You did not suspect that there was a leak between two sections of hose or one of the sections of hose after the first one when those seemed to present the leak/increased air in the pump basket? How are you attaching the vacuum hose? A vacuum plate or directly into the bottom of the skimmer?

 

[OldPoolMan]

Hi Zorks. It sounds like a suction leak for sure. Look for; leaks in the fittings around the suction intake of the pump, leaking pump seal or gasket, any hose leaks, air leaks in a valve in front of the pump, and of course, the lid or ring. To help you go through these items, here at TPC there is a link about finding a suction leak.

 

[zorks]

Thanks for reply guys!

You did not suspect that there was a leak between two sections of hose or one of the sections of hose after the first one when those seemed to present the leak/increased air in the pump basket? How are you attaching the vacuum hose? A vacuum plate or directly into the bottom of the skimmer?

The vacuum hose sections are only about a meter each, I made sure they were under water when I attached them and looked at the pump basket. I assumed it was not a hose leak since I did not think it would cause a loss in prime by introducing air if all the hose sections were under water. I also tested with a longer single piece hose and it also cause the prime loss. I thought maybe the hose length caused aggravated whatever condition caused the bubbles to cause the prime loss.

Hi Zorks. It sounds like a suction leak for sure. Look for; leaks in the fittings around the suction intake of the pump, leaking pump seal or gasket, any hose leaks, air leaks in a valve in front of the pump, and of course, the lid or ring. To help you go through these items, here at TPC there is a link about finding a suction leak.

I'll try to go through that when I have the time, I was hesitant to take the motor/pump off as it looked like a pain to remove and put back together. I forgot to mention, I watched a youtube video saying the pump union outer coupling screw should be flush with the back when it is screwed all the way in, but when I lubed the o-ring for the coupling, it didn't seem physically possible to make it flush (the outer coupling member was not wide enough to reach the back fully). Thanks.