Air in filter after pump has been shut off for awhile

[charleenthomas1]

When my pump is running there is no air in the system even when I vacuum there is no air in the system however when the pump has been shut off for 4 to 6 hrs the filter gets air in it and blows into the pool on start up and then clears up. I don't know if there is air in the pump pot as I have a black lid because of Baquacil but there is definably no air going into the pool or air in the filter while running. My multi port is new as of last fall. I don't have any water leaking anywhere and the oring on my air release is new. Does anyone know what could be causing this?

 

[cowboycasey]

Air will slowly get into the filter and system.. Should be no issue once the pump is running

 

[charleenthomas1]

But it never use to do this and its quite a bit of air.

 

[cowboycasey]

it may be the air relief valve on the top of the filter? I had to change mine this year...