As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT NOTICED A "LOW HYDRAULIC FLOW" ANNUNICATOR LAMP WAS ILLUMINATED AND DEVERTED TO GET MX SERVICE. TECHS FOUND RT ENGINE DRIVEN HYD PUMP LEAKING, HYD FLUID AT A LOW RATE. THEY DID NOT KNOW HOW LONG THIS CONDITION EXISTED. R & R THE HYD PUMP AND SYS TESTED SATISFACTORILY.