Thanks Guys!
We found it. It is indeed the number 2 hydraulic pump drive shaft seal.
@Shlaaper:
I´m not fiddling around with it.Since I'm only the driver and not a mechanic.
I am not overly self-confident, not allowed to perform that job, not trained to do it, so I will have someone down here who is!
And...my a$$ is sitting in that machine as well and I have family...
But I have to analyse where the problem is so the guys know which parts to order and have the mechanic fly in with the according special tools.
Thats also part of CRM, right?
I thank you for your help.
GG