Brushes are carbon brushes that remain stationary and deliver electrical power to the rotating part of the motor.
Relatively easy to replace and relatively inexpensive.
YouTube has a video that shows how...
http://www.youtube.com/watch?v=0GmtRBiXLFc
It's interesting that you don't know where the brushes are (or presumably what they do) but think they may be the cause of the machine's problem - "packed in."
If your wild guess is correct then it's your lucky day.
Good luck...
Peccavi
June 2009