can go down to an electronics store and buy replacement brushes. I would do that sooner rather then later because if you run out of brush you run the risk of damaging the area where they seat. Warn out brushes could cause the motor to run intermittently because you get what they call, chatter. The springs that hold the brushes won't have the pressure pushing down on the brush because it's shorter then it should be. New brushes will extend and touch with plenty of room and the springs well compressed with extra room for wear.