when replacing the rear bearings in this 2002 Focus SE it is necessary to replace drums, bearings,magnetic wheel seal, brakes, and the rear bearing nuts (these are only good four removal times according to the Ford Manual). The ABS light will stay on if you do not replace the magnetic wheel seal. You will most likely get that same rumbling noise during braking if you do not replace the brakes at the time of bearing and drum replacement.
I replaced all of what you said and the light is still on.....
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