Bearing grease

How much grease should I fill my bearing with? As a rule of thumb, never more than 30%. If however your application is very high load and very low RPM then a greater grease fill may be beneficial. You should NEVER fill a bearing totally with grease as it will almost certainly hydraulically lock, especially if the bearing undergoes a relatively quick start up acceleration. If the grease cannot escape then it stops the rolling elements moving (you cannot compress a liquid)