A hydraulic fluid system for a mobile machine includes a closed loop hydraulic fan circuit. The hydraulic fan circuit includes a primary pump, a motor fluidly connected to the primary pump, and a fan driven by the motor. The hydraulic fan circuit also includes a supply passage extending from the primary pump to the motor, a return passage extending from the motor to the primary pump, and a first accumulator selectively fluidly connected to at least one of the supply and return passages via a charge valve. The hydraulic fluid system also includes at least one open loop hydraulic circuit fluidly connected to the first accumulator.