My "anti-lock" warning lamp is illuminating on my car (1985 380SE sedan) and I am wondering if (and how) a MB dealer, or an independent MB dealer checks the system.

Here is what happens. When I first leave, my driveway goes down a slight hill/curve and I have to depress the brakes. At that time, I can feel a further down movement in the brake pedal, as if the ABS is activating, then shortly the "anti-lock" light is on. Sometimes if I am in town and on the level, the ABS does not illuminate for a while (sometimes), but most always the first time I depress the brakes (when going forward), after I start the car, I can feel the brake pedal make some funny moves, but then it never does it again.

I have been told it was probably a sensor, but before I shell out $141 for a sensor, I would like to be sure. Can they tell which sensor it is, if it is indeed the sensor/sensors?

Also - I am about to change out the rear brake pads. I keep hearing something about "brake bleeder". What do we need to do and where can I get one of these? Any local parts store? I am confused as to why this is needed, as we have never used it before on any other of our American or Japanese cars in the past when we changed the brake pads.

Thanks in advance!