As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT AT FL410, LEFT HYD QTY AT 22 PERCENT. NOTICED 1 PERCENT DROP EVERY 3 MINUTES. AT 19 PERCENT, AMBER CASS MESSAGE HYD VOLUME LOW ILLUMINATED. CONDUCTED CHECKLIST. HAD TO BLOW DOWN GEAR FOR LANDING AND USE THE EMERGENCY BRAKE UNTILL STOPPED. R & R LEAKING LEFT HYD PUMP IAW MM 25-10-02. OPS AND LEAK CHECKED GOOD.