suctiion air leak

[aussieta]

about two weeks ago i was very busy and didnt empty the skimmer basket for a week
anyway the basket became overfilled and then floated and settled side ways
the excess leaves then went through to the pump strainer basket and filled that too
after cleaning everything i now seem to have a suction air leak
continuous flow of small bubbles and lines all drain back when pump off
i have checked and double checked and lubed the strainer o-ring
i am thinking there are leaves/twigs blocking the pipe from skimmer to pump causing a prior air leak to be more noticeable
or the seal between motor and pump may have gotten hot and damaged
any thoughts???

 

[duraleigh]

Have you read the article on suction-side leaks in Pool School?

 

[aussieta]

i have read the article several times
i am wondering how common is an input seal damaged from overheating
water level is halfway up skimmer
all pvc connections appear good
nothing changed except the leaf blockage and opening and closing pump strainer lid
which i inspected and relubed
(several times now as it is most common cause)

 

[duraleigh]

Suction side leaks can be hard to find. Often, it is simply an issue that llooked good at first, but the leak was found on closer inspection.

Without physically being at your pool, the only advice is to remember that leak is somewhere between the skimmers and the pump.........they don't happen anywhere else so don't spin your wheels looking on the pressure side.

It's there, you just have to keep searching.

 

[aussieta]

yeh i know,
i am a forklift mechanic and am used to suction side air leaks
none of the pvc pipes were disturbed, and are glued except for union before pump
i have checked the pump basket o-ring so many times and can't see any faults, i may replace it anyway
the pump may have been starved for several days so am concerned for the input seal

 

[jblizzle]

By input seal do you mean shaft seal?
Did you check the o-ring in the union before the pump?

 

[SwimAustin]

I recently ran my pump dry by closing off the valves to it. It must have exploded, because it blew the 2" threaded PVC pipe off the top off the pump by a few inches. It also popped the skimmer lids and the cap on the main drain safety valve. I had to fix a number of suction side leaks after that. The hardest to find was the drain on the strainer basket. That o-ring was falling apart. I have no more bubbles and I didn't have to pull the pump apart. I'd recently replaced the shaft seal in spite of my stupidity it doesn't seem to be leaking.

I found this post and the one I liked above, because I was worried the leak was in the shaft seal. Based on my own experience on my pump shaft seals are pressure side. Before I replaced that seal, it was leaking water, not air.

The best thing I found was to run your pump on high, then quickly shut it off. The momentum of the water will push water out the leak. That trick didn't help me, but it looks like a good idea.

 

[jblizzle]

The best thing I found was to run your pump on high, then quickly shut it off. The momentum of the water will push water out the leak. That trick didn't help me, but it looks like a good idea.

My previous pump ALWAYS squirted water out of the pump lid seal when it shut off. But, it never sucked air in. So, this method will not always identify the problem.

 

[Poolguy1]

If its a pool only and the pump ran dry you may have warped the male adapter coming into the pump. Can you take a few photos of your configuration? Are there any valves prior to the pump?

 

[aussieta]

well the goodnews,
after dismantling and lubing every union
i made it worse, to the stage the pump couldn't prime
which allowed me to find
one pvc pipe fitting had never been glued from 15 years ago

 

[duraleigh]

one pvc pipe fitting had never been glued from 15 years ago

Nice work.

This is a good example to all of us that suction side leaks CAN be tough to find, but always remember that if you are accumulating air in your system, it is coming from the suction side of your system and that helps narrow the search.