Pump losing prime when shut off. Sucking sound from waste line.

[Thinkly]

I recently opened my pool and have since discovered that my pump loses prime after it shuts off. (at night) It manages to re-prime itself so far but I am concerned at some point it won't. There is a sucking sound coming from the multi-port at the waste port and when I put my hand over it quits.

I decided to plug the waste port and see if it maintains prime. So far it has. This seems odd because everything I have read says that any air entering the system must come before the pump. I am guessing there is a bad multi-port gasket but I am no expert.

I have lubed and checked the pump basket lid gasket and it looks ok. I don't see any bubbles in the pot or in the pool. Anyone have any ideas if I am on the right track???

 

[JasonLion]

That is almost certainly a problem with the spider gasket in the multi-port valve. Replacing a spider gasket is usually fairly easy.

Air in the pump strainer basket while the pump is running is a suction side air leak. But air while the pump is off could be a leak anywhere.

 

[duraleigh]

This seems odd because everything I have read says that any air entering the system must come before the pump.

Yeah, like Jason says, that applies only if the pump is running. I believe it to be the spider gasket as well.

 

[Thinkly]

Thanks for the replies and for confirming my suspicion. A couple of questions on spider replacement.

I plan to order this gasket. http://www.amazon.com/dp/B0031U7AQI...TF8&colid=3DAKXKY75B8U2&coliid=I3JZB3HC9RKIA2

I've read different theories on adhesive for the gasket. Some say super glue. Some say use the blue RTV gasket maker stuff. Some say use nothing. I plan to order this as that seems to be the concensus? http://www.amazon.com/dp/B0002UEOKK...olid=3DAKXKY75B8U2&coliid=IZP7LIB8OS2K5&psc=1

Sound OK?

 

[JasonLion]

I'v never seen gasket maker used except when it is impossible to get an appropriate replacement gasket. You definitely don't want to use that as an adhesive.

I recommend super glue. It makes it a little more difficult to remove the old gasket when it wears out, but otherwise gives the best results.