Replacing vacuum pump in a 124 diesel
I am about to replace the vacuum pump in my 1991 300D2.5. This is the pump that mounts to the front of the engine. In the MBZ shop manual it says, "During installation make sure that the lift curve of drive flange is at its BDC." What does this mean???
With the new part came an information sheet that says, "Install vacuum pump only if the stroke curve is in perfect condition" I am lost, I was under the impression that this was a simple R & R job.
Does anyone have any experience with replacing a pump on a 124 diesel??