If you have a Piston type Pump there is 2 rebuild Kits.
One for the Piston and the Valves and another for the Arm and Bearing that faces the inside of the Engine. And, neither Kit comes with a new Check Valve.

When you buy both kits you have spent as much money as a New Vacuum Pump and the new one will come with a warranty.

__________________
84 300D, 82 Volvo 244Gl Diesel