Should air come out when I hit the 'bump' button?

[BassetsForBrown]

Hi,
I have a cascade canister filter, and the instructions say to repeatedly push the 'bump' button if air gets into the filter. However, even when I'm sure there is no air in the filter, when I 'bump' it a few times, air bubbles come out of the output head.

Does this mean I have a leak somewhere which is causing the bump button to actually introduce air into the system instead of expelling it? There is no water leaking so far as I can tell, so I'm confused.

Thanks for your help,

 

[pops]

you are talking about the primer pump yes? this is just to prime the canister, if the outlet hose is full of water no need to keep pumping, just turn the canister on. the primer pump well create cavitation(sp)
esp with new water and well keep passing that down the line to your outlet.