Recently as I brake to a stop I hear and feel a weird buzzing noise and feel a vibration in the brake pedal. Its not the actual brakes, it sounds mechanical or electric. Any idea what it is?

 

If it's what I think it is, it's the ABS doing something weird. My car demonstrated something similar while braking at certain speeds, and it turned out to be either bad ABS sensors or ABS sensors not close enough to the speed ring, in either case the ABS wasn't properly reading one of the wheel speeds correctly. As soon as the ABS module realized there was a problem it did its 3 beeps and shut the ABS system down, and normal braking (minus ABS) was restored.

For me, I encountered both cases, the latter occurring after reinstalling ABS sensors.

If you have or have access to a VAG-COM, you can access the ABS module while driving and have it display the individual wheel speeds. If it's what I think it is, as you brake you'll see the wheel speed on one or more wheel showing erratic readings.

 

I experience the same feeling while braking when I near a complete stop. Check your brake master cylinder reservoir for cracks where air could be entering the line. I noticed mine has formed a nice crack on the top that I plan on "fixing" tomorrow until I pick up a new one.

 

As soon as you said ABS I figured what it's related to. Tomorrow morning at 8 a.m. I'm FINALLY getting one of my bad front wheel bearings replaced along with a new hub. I've been driving with a bad bearing for almost a year now (almost 25,000 mi.!). The past couple of weeks, the ABS light comes on after driving for a while which I heard is a common symptom with having a bad wheel bearing.

 

What you are describing here (not the wheel bearing) is EXACTLY what I was getting when an ABS sensor wasn't pushed in far enough, or the ABS sensor is bad. Unfortunately, it is difficult to diagnose this without a way to read each wheel speed such as VAG-COM.

Although - this is just speculation - if the wheel bearing is bad enough if could have knocked the ABS sensor ring off, or could have messed with the ABS sensor. Believe it or not, I've experience both of these occurrences...

 

+1 here

 

Well, the new bearing and hub are now in. The buzzing happens more often now and the ABS light is on all the time now instead of after driving for a while. Maybe after he messed with everything, the sensor died completely because the ring should be tight now right? Also, would I just have to take the wheel off to replace the sensor or do I need to pop the axle out and everything?? Thanks.

 

To replace the sensor you just need the wheel off. Although using VAG-COM to find out for sure which sensor it is would be a good idea, because it could be any of the sensors.

 

Ok. Thank you.