My Bosch washing machine drum stopped running. I ordered replacement motor brushes because the motor resistance varied as I rotated the motor by hand. Mainly it was open circuit.
I removed the motor and could then see that the commutator, to which the brushes make contact, is very dirty and scratched.
How can I clean the surface of the commutator without damaging it or bridging the segments by debris, before I fit the new brushes?

Alan, July 2014

As service engineers we fit the brushes, then set the motor to run on spin speed, and when getting up to speed use a carborundum stick ( commonly called "com stick") to dress the commutator and bed in the brushes whilst it is running. Health and safety risk assessment.... Only proceed if you are confident of your safety, during this operation the exposed brass terminals of the brush holders will become live,possibility of electric shock, the process also requires you to contact rotating parts, keep loose clothing, sleeves any neckwear (ties Pendants etc) away from moving parts. (Obvious but we have to say that for H+S)

Kenjo, July 2014