Don't know if this has to do with my problem but I discovered a minor vacuum leak in the hose going to the brake booster on the booster side. When I removed the line I noticed it had a strong smell of gas in it. I put a hose clamp on the booster side. At idle I did notice a variation of rpm when I pushed on the brakes. The brakes work fine so it is not affecting the functionality of the booster but maybe its an issue with the booster