I recently purchased and install a NEW PM system, as the old unit had an internal leak. Everything seems to function properly, great feel to the pedal as well. I have noticed recently a squealing noise coming from the PM unit just before it turns off. This noise only happens when I put the ignition on without starting the car, and when the car is warmed up...after a drive. When the engine bay is cool or the engine is running I do not notice the squeal. I have heard this squeal on my other brake system, and some hydraulic machines at work as well. Has anyone experienced this...I am hoping that this is pretty normal for a hydraulic system
TIA
Bob
I also have noticed a squeal(whining noise) coming from the PM unit also on my 87 GN. It does it when I start the car and anytime I hit the brake pedal. When I come to a complete stop with the tranny in drive it makes the same noise until I start moving again. Is this normal or is a bad sign??? Fairly new to these cars and still trying to learn. Thanks for any info.
John
I would not consider a squeal from the PM to be 'normal'. I'd suggest going through the diagnostic information provided at http://www.gnttype.org/techarea/brakes/brakespage.html and seeing if your symptoms may indicate a failing pump/motor assembly.
Mine makes a similar squeal just as the motor is shutting off. It has always done that. I don't hear it either while the car is running, just can't hear it, but if I stick my head next to it, I can hear it. When you first turn the key on, the pump turns on to pressurize the setup, atleast I'm pretty sure it does, mine does. I think it's because we hit the pedal a few times as we get out or in, and maybe decrease the pressure in the system. The pump running can sound like a groan, with a squeal as it shuts off. Atleast that's what mine's always done.