As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSTALLED NEW VACUUM PUMP: WITHIN 98 HOURS, PUMP WAS INOPERABLE. CAUSE WAS BROKEN PUMP TO GEAR DRIVESHAFT TWISTED OFF. CHECKED AND FOUND NO ENGINE STOPPAGE OR INTERNAL PROBLEM WITH ENGINE TO CAUSE BROKEN SHAFT. SUSPECT CAUSE - VANE IN PUMP STOPPED PUMP ROTATION.