By means of the vacuum cleaner and the
provided white brush (20 mm wide), clean the
marked areas from any dust particles.
Be very carefully not to contaminate the brake-
disk with any grease or oil! It will reduce the
brake-force. If it happened, take a Q-Tip and
solvent to degrease the disk as good as possible.
Replace the brush if it had contact with grease or
oil. Do not use hard tools or screwdrivers, it will
deform and damage the brake-disk.