vacuum pump oil leak

I have a bit of oil leaking out on the right side of the engine I notice it around the end of the vacuum pump, the end away from where it mounts to the block,If I dry it all off I cant seem to get it to leak at idle or fast idle, but if I drive around and check the end of the pump is wet with oil and the front capped bore in the pump end has a bit of oil in it, maybe it only leaks when the brakes are pressed? or maybe it is just getting blown there while underway from somewhere alse?
Is the pump servicable or is do I just have to replace the whole thing. The power assist on the brakes works fine. Anyone been there?
Thank you

Everybody been there ...

According to LR the vacuum pump is not a serviceable item.

But, there is a "fix" for it: 300tdi vac pump and there was another place (which seems no longer available) with a step by step guide. Here is what you could find there: RapidShare link