Replacement Vacuum Motor Brushes are sold individually
and each motor uses two. Occasionally only a single brush may need replacing because only 3/16" of carbon is left. Replacing brushes that have worn all the way down and scored the armature will wear down fast and be of little benefit. We suggest replacing the motor if the armature is scored. Also, once a motor has run its life expectancy of about 800-900 hours it is best to replace the motor, not the brushes. Note that 120 and 240 volt brushes are not interchangeable. Checking and Replacing Motor Brushes.