Vacuum filter dark black, (Fuel filter Purolator# F21124) ...
This was the only warning before the vacuum pump failed.
The piston shaft threads stripped, the nut worked down the shaft until it broke the vacuum pump cover.
Repair required locating a used pump at the local salvage yard.
The only other option was to buy a new vacuum pump.
PART NUMBER SEARCH RESULTS WITH PRICES
Vehicle 1985 Mercedes Benz 300D Turbo
Part: Diesel Vacuum Pump
D3000-11694 Diesel Vacuum Pump Pierburg IN STOCK
http://catalog.peachparts.com/item.wws?sku=D3000-11694