Check to make sure the cutoff lever stays up when you start the car, too -- if the vac switch on the dash is bad, it will stop as soon as the vac comes up! If this is the case, the temp fix is to unplug the vac line on the shutoff, and stop the engine with the lever (big pain, but better than not running!)

If the lever stays down with no vac on the shutoff, you should wait until someone with professional advice answers -- it could be a serious IP problem, and you should NOT mess about with this pump.

The o-ring can be replaced by one the same size from an assortment.

Peter

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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!