A method of controlling a fluid actuated fan drive system (12) for an engine (14) includes determining an engine speed. The speed of a fluid actuated engine-cooling fan (16) is limited when the engine speed is greater than or equal to an engine over-speed level. The fluid controlled fan drive system (12) includes a sensor (31) that generates an engine speed signal. The system (12) also includes the fluid actuated engine-cooling fan (16) and an engagement circuit (36) that is coupled thereto. A controller (28) is coupled to the sensor (31) and the engagement circuit (36) and limits operating speed of the engine-cooling fan (16) to less than a predetermined level when the engine speed signal is indicative of an engine over-speed condition.