I have a 1991 4-matic that is working fine,but I also have a leak in the hydraulic system. The leak is coming from
what looks like a pump. it is located low and next to the engine on the drivers side with hoses coming from it. At first it looks like an air condition pump. Can someone explain what this pump is and what it does . also I do not have hydraulic suspension in this car and I cannot figure out how to check the power steering because the cap does not come off. The leak seems to be coming from the pump or a hose fitting next to it ,and I have to add a bit of fluid every 2 weeks