Water coming back up air valves in jetted bathtub?? Causing leak??/

I just replaced the breaker of my jetted bathtub. I then ran tub to clean it but discovered I had water comin out of the air vents and after running tub twice for 15 min. had water leaking below the tub. Is there some form of backflow valve that allows water into the air system or is part of the pump not working? (Water is circulating very well but there is backflow of water into air system.)
Are there diagrams of these systems and how they work?

Thanks in advance.