If you are getting no vacuum from the pump, then a pump service is due. This is a fairly straightforward process that you should not be intimidated by. Alos, be aware that rebuild kits are readily available for your car and if you are mechanically inclined (sounds as though you are) it would be worth doing.
\'87 Mer-B 300D (220,000 miles) (sold)
\'93 Mer-B 300D (173,000 miles) (sold)
\'87 Porsche 928 (101,000 miles)
\'98 Dodge Ram quad-cab (250,000 miles)
\'2001 CLK430 Cabrio (50,000 miles)
Past cars: 1969 mercedes 250, 1981 300D, 1972 220D