Brake pedal vibration


#1

I have a 99 VW Beetle. Occasionally, the brake peddle will have a heavy vibration or jumping feeling (like a resistance pushing back against the pedal continuously or almost as if gravel is between the brake pads or ) while braking. IT IS NOT THE NORMAL ABS PULSATION. It does it at times that your ABS system should not be operating such as normal braking at an intersection. The car does not pull in any direction or vibrate in the steering wheel at all.



The ABS light does not come on everytime it does it and sometimes it comes on and stays on for a while and then goes off when it wants. The light will also come on going over a rough gravel surface like and old back road.



The shoes were replaced last year and the rotors were replaced in the spring along with flushing the brake fluid system. Prior to this, my daughter did have a rear brake that was down to the metal. The only things left to replace are sensors, calipers, or ABS system itself. Car has to many miles for warrenty work. What do you think it could be?


#2

[b] IT IS NOT THE NORMAL ABS PULSATION. It does it at times that your ABS system should not be operating …

The ABS light does not come on everytime it does it … The light will also come on going over a rough gravel surface like and old back road. [/b]

Well it sure sounds like ABS. It would appear you may have a sensor or two going bad. It is something in or affecting the ABS.

I would take a good look and make sure all the tyres are the same size and check to see if the computer has stored any error codes. You don’t need a A VAGCOM to read them so you should be able to have it read free by one of the large auto parts stores that do that for free. If they find any post the actual codes back here.


#3

All the tires were changed (new ones installed for a teenage driver) at the same time. I thought it may be a sensor because the light would come on sometimes on a rough road. The ABS system can only be read when the light is on…correct? Because the light doesn’t come on that often and usually goes off soon also…but the pedal will have the bad vibration/resitance pulse without the light lit.


#4

How difficult job is it to change wheel spped sensors. I notice that it doesn’t really go into detail in the Haynes manual about them.