Rick
Sorry I don't do layovers anymore. After flying worldwide in the military and domestically with American. I got real tired of the hotels and all the crap associated with them.
I just do turns now, fly out to a city and turn around and fly home in the same day. Instead of flying the 767 internationally or the 777 internationally, I fly the MD 80 domestically. I'm pretty senior on the aircraft so I just fly turns. Usually to the west coast. SFO, SAN or SJC. This way when I fly I get a lot of hours per day, which means less days of work for the month. And when I return from the turn I've usually flown 7.2 to 7.5 hours. I cannot be used for anything but the drive home (8 hours of flying in the air per day is a maximum set by the FAA). I'm getting to be one of those senior guys that the junior guys want to retire. But I have 10.5 more years.

Fisherman.
To my knowledge, and I could be wrong, wouldn't be the first time. On the 240D and 300D/CD/TD, with slight variations in each model. The vacuum pump pulls vacuum but over the many miles of driving the diaphram in the vacuum pump, or piston seal in the piston type, can fail and allow oil to slowly move into the vacuum system. Since a vacuum remains on the system once the engine is turned off, the oil in the vacuum pump, that is getting past the diaphram/piston seal, is slowly sucked into the lines of the system.
Additionally the vacuum shutoff in the injection pump can allow oil to get into the vacuum tubes the same way.
On the 240D in 1983 the vacuum system is NOT connected to the intake manifold ( I'm positive, I just looked). So oil cannot enter this way. The connection simply does not exist on the 83 240D. Now on my 82 300TD and my 86 300SDL the vacuum system IS connected to the intake manifold. I figured the engineers at Mercedes realized that the poor 240D has absolutely no power as it is, so for God's sake, don't steel anything fom the intake. Just my thoughts!!!
The brake booster is a possible entry point for the oil, or in this case brake fluid which by the time it enters the lines would probably be black and look like oil. I will check the booster when I remove the booster/master cylinder to install the swaybar mount bushings. At that time I will replace the Oring to the master cylinder and check the MS for leaks. Is the master cylinder leaking? I have not had the car long enough to determine that by observing the fluid level. Actually I just replaced the brake reservoir to master cylinder orings. They were leaking. I will check the MS when I remove the booster.

Thanks for the input.

Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car