A protection mechanism for a lubricant reservoir is mounted within a valve protection chamber disposed on an actuator. The protection mechanism includes a valve actuating plate and an elastic member biasing the valve actuating plate upwards. The actuator is pushed upwards by a rising level of lubricant as the lubricant reservoir is filled. When the reservoir is full, the actuator causes the valve actuating plate to contact a valve stem. The valve actuating plate pushes the valve stem up to shut off a flow of lubricant to the reservoir through the shut off valve. During an overfill event the actuator shifts upward due to the rising level of the lubricant in the reservoir. As the actuator shifts upward, the elastic member compresses such that valve actuating plate remains static relative to the lubricant reservoir as actuator rises.