Thanks Dave for the input. What I am referring to is the vacuum pump on the engine. Diesels do not create vacuum like gasoline cars, so there is a pump that creates vacuum.

I did find some information on the CD, it says "IF THE ROLLER OR BEARINGS OF THE PISTON VACUUM PUMP ARE DAMAGED CHECK WETHER THE DRIVE FLANGE WITH CAM AT THE INJECTION TIMING DEVICE IS DAMAMGED. REPLACE PART IF NECESSARY"

What the heck does this mean????????