Air sound issue
 

There was another post that I think was referencing the same problem but I just decided to start another one in case it was different.

I have an air leak from my brake. It is coming from the rubber boot that goes into the firewall on the inside of the car. If I move the boot around it changes the air leak noise. It also appears as though there is some break fluid on the rubber boot itself. The thing that suprises me is there is no check engine light and my brakes seem to work fine. What could this be? Vacuum or booster? Either was it sounds like it is a common problem What would I do to fix it and how much would the parts cost? I do have a warranty so I would probably just pay the deductible and have someone else fix the problem.

What do you all think?

RE: Air sound issue
 

The brake booster is bad.
Also check the back of the Master Cylinder if there is brake fluid there you will need to replace both the Master Cylinder and the Booster.