I have a 1986 560 SEL. On the engine directly under the alternator there is some type of pump. It is driven by one of the belts and has two hoses attached. It has the words "no oiling" printed on the side. I checked under the hood and found that one of the hoses had become disconnected from the unit but the engine seemed to running OK anyway. I have re-attached the hose. Just what is this unit and what does it do?