Vacum pump failure

[Shark]

last night my vacum pump failed.
I pulled it apart today and one of the check valves on the bottom was broken. I removed all pieces except for a piece of metal that was broken and went somewhere in the engine.
This pump has the old bearing style and mercedes has updated the bearing to a solid one so engine failure won't occur.
So
After rebuilding this once and it failing, Mercedes says u need a new one for 300+ dollars.
The $40 rebuild kits are not available and You wouldn't want to risk having ball bearings in your motor.
What do you guys do?

[Diesel911]

There is actually 2 rebuild kits. One for the Piston and Valves and another for the Bearing and Pivot Arm assembly that faces the Engine. Unless you shop around and find a place that sells both cheaply you will spend almost $300 rebuilding it yourself and have no warranty.

And then there is:
New Vacuum Pump Ruined due to too much Timer Shaft End Play (the title from my notes).
second vacuum pump, help! on a trip-Toronto