i just want to validate my thoughts on this with the knowledgeable folks on this forum.
when i clean my pump basket, before i open the lid i close the intake valves on main drain and skimmer lines and move selector handle from "filtering" to "close". regardless of that i often have the water draining from the basket past the intake line. it has no place to go but towards the filter. i thought i had a leak somewhere in the filter but it was all dry. i opened the bleed valve on the filter and it start sucking the air in. then i noticed that there is some water coming out from the pool returns.
so it seems that my multiport gasket is bad and it let the water from the pump to be sucked by gravity thru the filter back to the pool. i also get some water in discharge waste port, but since it's capped it's not a big problem.
is this a correct conclusion? how bad is it if left as it? are the any special trick about changing the gasket? it seems that it would be spring loaded, so i don't want to get in a situation where i'm not able to put it back together without a special tool.