Welcome to TFP!
By filter catcher, I believe you are referring to the pump basket area, just so we're speaking the same language. And when you attach the vacuum, your having air bubbles coming out of the return jets back into the pool?
How do you know the pump is leaking at the impeller?
My thoughts would be that you're getting air from your vacuum head or vacuum hose. The alternative is that if you're only pulling suction from the vacuum head, you have a suction side leak or as you have said, a leak in the impeller or pump seal that is pulling in air with the decreased suction side pressure when only using the vacuum head.
Just an air leak would not cause the intense, persistent bubbling over your whole pool surface. The only way you'd have this foaming is if there were a chemistry problem, such as very low calcium hardness (CH) or if you had introduced a detergent or surfactant into the pool. This can happen from some products designed to be used in pools (but usually don't need to be used) or from using an outdoor or splashless bleach, which both contain surfactants. Have you added any clarifiers, algaecides or splash-less bleach to the pool recently? Be specific about products if you have.
Also, a complete set of test results would certainly help. Do you have a test kit to use at home?