Powermaster Buzzing??

[BASS]

Ok, when I press on my brakes and keep them on, I can hear a slight buzzing noise for 2 seconds and then it goes away (while still having my foot on the brakes the whole time). And, sometimes, the brake light would come on (especially during hard braking). Does anyone know what this buzzing noise is coming from? Proportioning valve, accumulator, brake switch????? As far as the brake pedal feels, its fine (not mushy or hard)....

 

[gofstbuick]

If it won't lock up during a panic stop, your PM motor is probably dying.

 

[zeus87gn]

No, your accumulator is probably dying. Run the diagnostics on GNTType.org to be sure.

The bussing sound you hear is the motor running and most likely trying to keep the accumulator pumped up and the acc isn't holding the pressure any more. Run the diagnostics to be sure.

HTH