Contaminants and foreign matter in the governor oil are the greatest single source of governor troubles. Use only new or filtered oil. Be sure that all containers used for the governor oil are clean. The time interval between governor oil changes depends upon many factors: type of service, operating temperature, quality of oil, and so forth. Anytime the governor oil appears to be dirty or breaking down from contaminants or excessive temperatures, drain the governor while it is hot, flush it with the lightest grade of the same oil, and refill it with fresh oil. In any event, follow the PMS for regular oil drain intervals.

A governor should operate several years before needing replacement if it is kept clean and if the drive from the engine is smooth and free from torsional oscillations. Except for isolated cases, so rare they can be almost disregarded, governors do not suddenly fail or break down. Instead, they wear gradually, and give an external indication of their condition in the form of slight hunting, sluggish operation, and so forth. Further deterioration is at a slow enough rate so that an exchange governor may be ordered for installation and the governor can be changed out at a convenient downtime.