Cleaning your bearings properly is a labor of love. It takes time and some persistence, but can pay of in smooth spinning, quiet bearings. The key is to follow the procedure carefully.
1. Remove the side shields.
2. Clean the bearings, filter the cleaner through a paper towel, and then clean them again.
3. Dry the bearings completely either by leaving the bearing overnight or use a blow dryer. It is important to dry the bearing properly for incase if any solvent is left, the new lubricant will breakdown faster.
4. Relube the bearings with the oil/grease.
Use separate containers for rough cleaning and final cleaning, and provide a screen to support a bearing. Paraffin or liquid gasoline may be used for cleaning. The inner and the outer ring should not be rotated while cleaning as they may get damaged. They should be left in oil preferably heated (not more then 120deg;C) for effective cleaning. During the final cleaning while the bearing is immersed in the clean solvent, the rings may be rotated for cleaning from inside.
To check the bearing after cleaning, hold the inner ring horizontally with one hand and spin the outer ring. If the bearing is faulty, a vibration will be felt in the hand.