Today, I noticed that all of the sudden my brakes felt like the car wasn't on. I'm guessing that would mean that my brake booster isn't working right. I checked the vacuum line coming out of the brake booster and it was fine. Vacuum was around 19 in hg when my finger was on the line and 16 when the line was hooked into the booster. Do I have to replace the whole booster or is there another option?