odd ball
Senior Member
Joined: 13 Mar 2006
Posts: 100
Location: San Francisco, CA |
sounds like a disc/pad problem. I can't think of any anti-lock parts that would make noise. ABS consists only of speed sensors on your axles, which hook to a computer, which controls a pump/valve assembly that is usually part of/ right after the master cyclender/ resevouir.
Is it the front or the back? Have you inspected the pad and disc for wear/warp/bad spots?
If the noise is coming from the wheels, it has to be a simple disc/pad problem. If it is coming from the pump and valve assembly under the hood, take it to the dealer. The pump/valve assembly should be doing nothing but letting fluid pass through it unless the ABS is activated, then it just pulses the valves. 99.9% of the time it is just sitting there.
My guess is that the pads are just oscillating at low speed. My car does this because I forgot to put on the isolating shims when I put in the last set of pads. It screams like crazy, a real head turner.
a small clip from a very long and boring Bosch Research paper on scanning laser Doppler vibrometer, and brake oscillation:
"Anybody who has ever spent time near a busy junction is only too familiar with how annoying the sound of squealing brakes can be. The noise actually begins just before the car comes to a stop, at walking speed."
In theory its the same principals as squeaky wiper blades. Vibration producing audibal sound. Your disc is vibrating and turning into a speaker! If the pads and discs are good, you can get disc brake anti sqeak at the auto parts store. It is like a tube of high temp rubbery stuff that you put on the back sides of the pad and it will isolate your pads from the piston and stop the vibration. _________________ ----------------------------------------
69 Fairlane 500, 351w, 2200 stall C-4, 9" with 3.50 and trac-lock
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