So last week my brakes felt soft, I looked under the hood and realized I was loosing brake fluid rapidly from from the rear compartment of my brake fluid reservoir. I checked connections between the reservoir and the master cylinder which are fine.Fluid appears to be leaking from the connection between the booster and the master cylinder but I cant' tell if it is also leaking from behind the booster. I don't get the "hard" brake syndrome that I read about in other threads, but the brakes do go soft within a day or so. What is the best way to tell if the booster is bad? Is this just a bad master cylinder even if it might be leaking from behind the booster?