There are two - they are on the motor. Motor Brushes are blocks of carbon graphite that remain stationary and deliver electrical power to the rotating part of the motor.
They rub against a copper ring divided into separate sections and called a commutator - the brushes wear out over time and you notice sparking noises, reduced performance and sometimes the smell of burning.
Here's a youtube video of changing brushes - the principle will be the same on all motors with brushes.
http://www.youtube.com/watch?v=0GmtRBiXLFc
In the video they take the motror out - probably because they could not get a camera inside very easily - you may well be able to access the brushes on your motor by laying the machine down on its side or back and approaching from underneath or perhaps just taking the rear panel off if that's possible.
Good luck...
Peccavi, February 2010
they will be inside the machine drive motor, pressing against the commutator there will be 2 of them mounted 180 degrees apart.
