I have a 41 chevy coupe street rod. When I apply the brakes my idle goes up about 2-3 hundred rpm. I have a bendix booster on it I bought from a speed shop and is mounted to the frame under the drivers floor. The car has been just sitting in the body shop for about 1 1/2 years. I built the rest of the car about 5 years prior to that. I have not done alot of work on this problem yet but my fear is that the booster has a hole in the diaphram, does this seem logical or could it be something else. I have noticed since I got the car out of the body the brake pedal does not come all the up after removing your foot. I'm not sure if these two problems are linked or not.