As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING RUN-UP OF AIRCRAFT PILOT REPORTED LOST OF INSTRUMENT VACUUM SUCTION. MAINTENANCE TECHNICIAN FOUND VACUUM PUMP HAD A BROKEN SHAFT. UPON REPLACEMENT OF VACUUM PUMP INSTRUMENT SUCTION WAS FOUND TO BE OK. RECOMMEND FINDING A REPLACEMENT THAT IS MORE DURABLE. (K)