One of the most important components of any electro-mechanical maintenance program is the lubrication of bearings. Yet, this vital aspect of preventive maintenance remains one of the least understood functions of maintenance. There is constant debate concerning whether a bearing should be 'flushed,' a limited amount of grease added, how often or if the motor should be operating or tagged-out. Many motor manufactures outline the preferred, and safest, method for lubricating electric motor bearings. There are specific physical properties for this process in the motor bearing housing and in order to protect motor windings from contamination.