Seeking some insight into my braking nightmare.

About a month ago heading out to shop with the wife, car was fine all days nothing out of the ordinary...50 miles on the thruway and upon exiting as I went to start slowing, I unexpectedly lost all vacuum brake assist. Fine and dandy, found that the brake vacuum pump had internally decided to leave the chat. Ordered the pump and replaced it and all was well for about a week. Again one afternoon, no vacuum assist. Checked all my vac lines etc, no leaks that I can find after checking about a dozen times now...However, I removed the main line and have discovered quite a bit of oil. Seeking some guidance on where its coming from and why this might be.

I assume maybe from the cam seal...When replacing pump, I thoroughly cleaned out the hole where pump slides in to the end of the cam. It was not real bad though, and very, very little oil at all. But figured I would try to get some insight here before I went crazy. Thanks!