Does anyone know if its okay to mix dexron III with power steering fluid? the dealer who sold the car to us flushed the power steering system and re-filled it with dexron III. I need to top it off becasue it is leaking slightly. I bought mercedes power steering fluid ($28/litre) and am planning on topping it off with it. should i just use dexron III (which I know is not meant for it, but its alreday in there) or from now just keep topping it off with PSF?