I have a 2001 Toyota Camry and it's making a High Pitched Whistle near the Brake master cylinder, I believe it's a vacuum leak but I cannot pin point exactly where. It gets louder with increased rpm but goes away if I stomp on the gas and real load when the car is turned off for a few seconds. has anyone else had this problem?

 

There could be a leak in the brake booster, the large can behind the master cylinder. The booster is powered by vacuum taking off the engine intake air system. You may be hearing an air leak in the booster can or air hose that runs to.