I broke down this past weekend and replaced my right front wheel bearing/hub assy. Since the dealer wanted $300 for a new one, I went with a quality reman unit from Eire Volvo for $75.

Since I was pulling everything off anyway, I went ahead and did the pads, new rotors, and caliper pins. I cleaned off both ABS pickups (diamond shaped tips) thoroughly with an old toothbrush and brake cleaner (both were quite covered in what I assume is brake dust and metal particles from the old rotors). I used a big pair of channellock pliers and the old pads to create clearance in the caliper for new pads.

Now my braking performance is great, and my crappy wheel bearing noises are gone. But now every now and then, very randomly, when I am applying hard pressure to the brakes at a complete stop, I will hear a sound and feel feedback through the pedal identical to the "start-up ABS test" I feel evey time I get in the car.

Is this because of a different air gap with the new hub? Did I squeeze some dirty fluid back into the ABS unit? Or did cleaning the pickups make them more sensitive? Should I even worry about it? If so, what should I do? Is the air gap even adjustable?