When I pressed brake pedal on the snow this winter, I heard grating noise.

Does your ABS also make grating noise? Or is mine defective?

1992 300D.

did the abs light come on? why do you suspect the abs? could be just the brakes are worn out. good luck, chuck.

The ABS malfunction light did not come on.

Brake pads and rotors are quite new. But they sometimes make squealing noise at low speed - this squeal sounds different form "ABS grating noise".


The manual mentions pulsating feel on the pedal, but not grating noise. So I would like to know whether mine has problem.


But on some document (I do not remember exactly. It might be an old article on Edmund - granting noise and pulsating pedal feel make driver not pressing brake pedal hard in emergency situation and bla bla bla . . .)

, grating noise is mentioned.

I think newer version of ABS is quieter.
I wonder how noisy W124 ABS is.

did the noise come from the wheels or under the hood? did the pedal pulse when the noise occured? chuck.

Mine does the same thing. Grating and squealing once the brakes are warm from 15 mins or so driving. I have fairly new (2 months) pads and discs. If I let off slightly on the pedal as the car comes to a stop I get some ABS pulsating.
I'm also getting more heat from the driver's side front wheel.
Taking the car into the shop tomorrow so we'll see if we find anything and I'll report back.

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1993 320TE M104
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past:

1983 230E W123 M102
1994 E300D S124 OM606 (x2)
1967 250SE W108 M129
1972 280se 3.5 W108 M116
1980 280SE W116 M110
1980 350SE W116 M116
1992 300E W124 M103
1994 E280 W124 M104
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"music and women I cannot but give way to, whatever my business" -Pepys

The pedal also pulsated.
With the windows closed on the cold weather, it was diffecult to locate the source of sound. I felt the the sound was from wheels.

I guess the ABS functioned, anyway.
The road was splippery due to snow: when I pressed accelerator pedal, the whole car body tended to spin due to real wheel slip. But when I pressed brake pedal, car body did not spin - probably ABS successfully prevented the wheels from locking -.

I found the grating web site.

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http://www.edmunds.com/ownership/driving/articles/43814/article.html

When ABS engages, a loud grating sound and rapid brake pedal pulsation often accompanies the pumping action. When this occurs, insurance companies and safety experts theorize, drivers assume that something has gone wrong with their brakes, and they begin to pump the pedal or simply lift off the brake pedal, which defeats the system.
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Then why did MB not include comment about grating sound?

i've always told people with abs on the car, go someplace safe and do your absolute best to lock up the brakes. when the abs kicks in, you'll know what it does and how it feels. there will be a noise-grating doesn't come to mind, from the abs servo along the the pedal pulsing. edmunds is right most people don't know how to react. that's why you practice if you can. if you are sure the brakes are ok, it might have been normal abs operation. good luck, chuck.

slightly warped rotors?

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currently just 1989 300SE 185k miles

The noise and the pedal pulsing (almost feels like rocks rattling around to me) are normal. Definitely a surprise the first couple of times it happens. With ABS, in order to get the best performance out of a braking situation, keep on the pedal HARD - the system will take care of the wheel lockup issue, and will apply the brakes, but only so hard as you keep pressing on the pedal.

Also, without traction control, ABS will NOT keep your car from spinning, if the lateral traction limits are pushed hard enough. (Actually with traction control you could probably still spin out, given the right circumstances)

all of the above noises of ABS on a slippery surface is normal.
be alarmed when it happens on a hot and dry surface.

__________________
joel

Prayers bring forth enlightenment.

ABS is not like the old days. In a panic stop with ABS, SSS = Stab Stay & Steer. MB found many, even professional drivers, would not let the ABS function to its potential, which is why they have now developed the automatic panic stop system. They also found, in early ABS crash data, they got fewer rear end situations than anticipated. They did expect an ABS car to be rear ended more often than the norm in the early days of ABS. This did not come to fore because drivers were letting up. The pedal sensations of ABS from all manufacturers has been lightened as well--so as to avoid freaking out drivers.

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David
1986 300E Anthracite + ECodes + MB Mileage Award