As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STANDBY VACUUM SYSTEM FOUND INOPERATIVE. ELECTRIC DRIVEN PUMP FOUND FULL OF THICK OILY SUBSTANCE. HOSE FROM PUMP TO FIREWALL WAS FULL OF THIS FLUID BUT THERE WAS NONE IN VACUUM REGULATOR. IT APPEARS THE FLUID IS FROM DETERIORATION OF THE HOSE. THIS IS AN EMERGENCY BACKUP SYSTEM THAT WILL FAIL WHEN IT IS NEEDED.