There is one more important thing to note: never crank hydraulic pumps unfilled or dry by hand or with the engine starting, this is the death of any hydraulic pump. On the high-gloss, lapped aluminum surfaces, which have a surface as smooth as glass, grooves and scratches occur when they are rotated dry, especially in the case of vane pumps, which leads to a loss of performance or other damage to the pump. Furthermore, this is also not good for the plain bearings, even aluminum surfaces. So don't unpack and play around with it, but fill the pump with oil and then you can turn it and install it. Fill both areas of the ABC servo pumps. We would like to send all pumps pre-filled, but we are not allowed to. See shipping guidelines and environmental guidelines. I know the curiosity is great, new spare parts and turning it first, but it is completely wrong and dangerous. At Mercedes, I know, the pumps are pre-filled. So before you install the pumps do not turn them, remove the plugs, fill the ABC area of ​​the pump and then fill the servo area, then you can turn it. Put the plug back on and then install it and never disconnect the suction hoses and remove the container with the old oil and reinstall it, this is often routine in workshops, but fundamentally wrong. The sealing plugs do not let dust or dirt fall into them during installation, nobody does an engine wash beforehand and some vehicles look bad in the engine compartment. But even relatively clean vehicles have dirt, dust and sand everywhere in the engine compartment, which is normal. When working, no matter who is doing it, something can always come loose and fall into it. That is death for hydraulic systems.