As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING 100 HOUR INSPECTION, FOUND ENGINE VACUUM PUMP DRIVE LEAKING OIL AND CONTAMINATING VACUUM PUMP. REMOVED VACUUM PUMP AND ENGINE VACUUM PUMP ADAPTOR DRIVE ASSEMBLY. FOUND SEAL P/N STD-1774 NOT FULLY INSTALLED IN DRIVE ASSY. REPLACED SEAL AND VACUUM PUMP, OPERATIONAL AND LEAK CHECK SAT. ENGINE HAS 168.7 HOURS SINCE OVERHAUL BY MFG. THIS IS THE SECOND OVERHAULED ENGINE WITH THIS DISCREPANCY.