Jim:

It DOES sit on the bottom of the housing when not running. It will also leak out of the clutch if you store one on it's face rather than standing up, as my mechanic finally pointed out to Benz a few years ago. They no come with the box clearly marked "this way up or part will be damaged". The fan will spin at engine speed on startup, until the oil pumps out of the working region. This means, of course, if you don't get ran "roar" on startup, the fluid is gone.

I'll dig up the W108 manual tonight and see if I can give a better description of the pump, I'm not too clear on it myself.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!