yes, it is possible, because the bearings of the axle are using the differential-oil. If the seal-rings are worn out it will be difficult to replace them. Mercedes took care that the oil will not come on the brake-pads. Therefore they designed the bracket für the seal that way, that oil will not spoil in the brake-drum and come out through an hole on the innerside of the brake-plate.
Normally the problem is the loss of brake-fluid! First take a look at the brake-cylinders. Replacement ist very cheap (about 10€/piece... you should have always some in spare ).
Hello,
the leak was not from the brake calipers.
I went to a car repair shop and they explained to me,
that the drive shaft bearing seals are worn out and must be replaced.
I got a call today that it was ready. I went to get it, but was unpleasantly surprised that they also changed the bearings on the drive shafts. What annoyed me a lot was that they replaced them with some world-Unfamous Chinese ones.
Here it is.
Peter, do I understand you correctly that there are some openings in the drum (or in the differential) that serve for drainage (ventilation)?
All the best.
Jack