I think I have break problems again. I have just replaced the accumulator ball and the red light is now off. However days later I turend off my 1987 Gn and heard this loud high pitch noise that I believe is a motor connected to my brakes. I pumped the brakes numerous times and turned back on the car. I then turned off the car and it stopped. Could this be a brake fluid level problem or even worse? Thanks for your help. I am so tired of this Powermaster system.