There are a few tips and tricks to fixing the leak issue on the n62 vacuum pump. The biggest issue is knowing how to reinstall it. You have to properly line up the vacuum pump lever with internal slot. Do this by rotating the engine clockwise and lining up the slot in the vertical position. It sounds more complicated than it really is. I caught hell when I did it, until I saw theses videos.

Replacing the vacuum pump seals Part 1
https://www.youtube.com/watch?v=9nRroLFTPJc

Part 2
https://www.youtube.com/watch?v=rAEz3BFe46o

Part 3
https://www.youtube.com/watch?v=Bxlo2odZ5N8