As a general rule, how much grease should be pumped into a pillow block with an unsealed ball bearing?

The appropriate amount of grease to pump into a pillow block with an unsealed ball bearing is determined by the need to replace old grease while ensuring that fresh grease can effectively lubricate the bearing. Pumping in grease until the old grease begins to flow out indicates that the cavity is full and that the new grease is replacing the old grease effectively. This approach helps to ensure proper lubrication and removes contaminants that may have accumulated in the bearing.

In contrast, pumping grease until it overflows would lead to overgreasing, which can cause excessive pressure, damage the seals, and lead to leaks. Coating just the ball bearing with grease would not ensure adequate lubrication for the entire bearing system. Lastly, relying on the pump to stop indicating pressure might not accurately reflect the lubrication needs, as it could give a false impression that the bearing is adequately greased without actually ensuring old grease is being expelled. Overall, the best practice is to pump until old grease flows out, ensuring both effective lubrication and maintenance of the bearing.