So here is the issue.

When I brake at a speed of 20mph or less, I get a grinding feeling from my brake pedal on dry pavement (there is nothing slipper in sight). It feels like braking in snow/ice and when your ABS kicks in, and you feel the griding in your pedal. It does not happen if I brake at speeds higher than 20mph and especially if I brake hard. It only happens if I brake lightly. It is not constant after the 20mph. It happens for a few seconds and then stops and then happens again maybe for a few seconds and stops, and by that time I have stopped (the vehicle has stopped). Let me know if you need more details on the issue. It's driving me nuts!!! Here is what I have already done on my car to get started with the diagnosis on this:

Needed new brakes all around so,

Installed new pads and rotors on all four wheels.

Afterwards, it was still doing the same thing as explained above. I found this site, and am going to further look into this, but it's costly. Shops want to charge anywhere from $100-150 for diagnosing this problem as explained in the site below:

http://www.fixya.com/cars/t1576235-b...dind_low_speed

"Sounds like your getting abs activation when its not needed. Most likley one of the wheel speed sensors has failed. You do need to have a scan tool to read the live data from the abs module as the problem is occurring to pinpoint which sensor is faulty. The abs light will not come on because the abs module thinks its just working normally. I'm an ASE certified mechanic and have seen this problem many times on various vehicles. You might have to pay somebody to diagnose it, but replacing the sensor it a very easy task. I hope this helps."

Now, could it be the speed sensor failing somewhere? Also, could the inner brake dust shield cause this noise if it is bent some? It does not seem to be touching the rotors, but the mechanic said it was bent some last time I had them check my suspension for something else (at the front brakes), but I have noticed this too when I replaced my brakes. Any inputs? I'm running dry on ideas!

 

you may need to replace your abs sensor ring. I had this same problem after I replaced all of my rotors and pads. when i pulled the rings out, they were corroded and paper thin. the new ones were thicker and worked much better.

Do you have an abs light or a brake light on?

 

I had the same thing happening. It was due to dirt that got into one of the ABS sesnors. What I did was remove all of the sensors and thoroughly clean the sensors and the holes in the wheel hub where they reside. 80k later things are still good!

 

No, the ABS or brake light are not on. Where your ABS/brake lights on? Also, how much are new ABS sensor rings? Thanks

 

How hard is this to do? Can you brake something easily by doing the cleaning. What did you use to clean them? Thanks

 

yes they were. when you clean your sensors, look at the rings and make sure they are still good. they are about $20 each if i remember correctly.

 

Are the rings easy to get at? What's required to get at the rings? Also, are the rings present in both the front and rear....or only at one end? Thanks

 

Hey all - sorry to resurrect such an old thread - but I am having the same issues. My front driver's side wheel feels like it is really grinding despite the new pads and rotors. REcently my ABS and Brake lights have been coming on and off. The ABS will stay solid and the Brake light will blink. They will come on randomly and sometimes only stay on for a second or two - or sometimes for lengths of time - but they always end up turning back off at some point.

I bet that it is these rings - Are they hard to get to and replace? I appreciate all the information, I am hoping I can get to working on these soon as the weather breaks.

 

I just wanted to add that my ABS isnt kicking is when it isnt supposed to - just the grinding. Also, when the lights arent lit the ABS works just like it is supposed to. I only mention this because frojm what I have read when the ring is cracked the ABS will kick in when it isnt supposed to. Could my issue just be the sensor? I have a 2.8 Quattro btw.

 

Bumping