Although brush assemblies come in many styles, if you analyze the two I focus on below you will notice certain commonalities present in all brushes: 1) the actual carbon/graphite brush, 2) a spring assembly that keeps the brush mated against the motor commutator as the brush wears, 3) a housing that retains the brush and allows it to be referenced against the motor housing and 4) an electrical connection to provide power to the brush. ...