I have a '92 300D 2.5 Turbo. It is equipped with the ASD (locking differential). Looking at the engine bay, there is a tank on the drivers side that holds hydraulic fluid that is connected to the power steering pump. There are hydraulic lines that lead down towards the bottom of the car and connect to the differential and then back to to the power steering pump. My question: Is the power steering fluid the same as the ASD fluid? Why the two reservoirs? How often do you change it? How do you change it? Its kind of confusing because the maintenance disk that I have mentions nothing about how to change this fluid. Thanks for the response.

Herb
'82 240D
'87 300SDL
'92 300D 2.5 Turbo