I am having trouble with the brakes on my wifes 96 S10 Blazer. 1. The pedal is hard all the time, and when you press down on the pedal, there sounds like a vacuum leak from somewhere around the back of the engine maybe. 2. When I pulled the vacuum hose from the booster with it running, the engine immediately revved redline and scared the wife (and me too) sh!tless. 3. I pulled the same hose from the booster a couple of hours after it was running and heard the "hiss" of vacuum being held. 4. Damn thing tries to quit running after you stop (like at a red light)and give it gas to accelerate. 5. Idles extremely rough. I thought that it was the booster, but would it hold a vacuum hours after it was running? Or could this be a screwed up EGR? I really need you guys' help. It is the vehicle my wife takes to work 35 miles one way and I worry about her safety. Any help is EXTREMELY appreciated.