I have not had a similar problem to what you are describing. The ABS interacts with the ASR by pulsing the brakes at a wheel that is shown to be slipping. Each wheel has a speed sensor, when the computer is notified that a wheel is turning faster than the others it sends a signal to the pump and the pump applies pulsing pressure to the brake on that wheel. I have had this happen with my SL and my S. I had the car up on a hoist and put it in gear. It doesn't sound like a clicking when it does it, it sounds like something rubbing and does not stop the wheel, just kind of kicks it a little bit. If you are not getting an ABS light, I would not think you have a malfunction in your ABS. Make sure they work, go down and empty road with no one behind you and slam on your brakes as hard as you can, if they pulse, grab and release (don't lock) your ABS system is working properly. If you are getting clicking while driving and not applying the brakes it could be something near or attached to your power booster/master cylinder. Check the vacuum line, make sure the booster is ok, you can apply pressure via a vaccum pump and see if it loses pressure, it could be pressure loss causing the clicking. If you have ABC, there is a switch in the power booster, It could be a lot of things causing the noise, if you feel it in your pedal how do you know it is the ABS pump, that is in the front of the car. I would not go and buy a new ABS pump if you have no warning lights and the system is functioning properly. If you don't know absolutely for sure what is wrong, take it somewhere and have it diagnosed. It is hard for someone to guess at what the problem could be without seeing it, feeling it, or driving it. Good luck!

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Brian W. Heitman

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