A leak detection system and method for fluid operated device includes a backloaded fluidic oscillator having an interaction chamber, a power nozzle at its upstream end coupled to a source of fluid under pressure and an exit throat at its downstream end. The interaction chamber first diverges from the power nozzle and then converges towards the exit throat. A pair of outlet passages are connected to the exit throat; one of the outlet passages is connected to the fluid operated device and the other of the outlet passages is connected to a fixed volume and a vent whereby the backloaded fluidic oscillator oscillates at a rate which is a function of the leakage of the fluid operated device.