As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON APPROACH TO RUNWAY 35, GEAR SELECTED DOWN FOLLOWED BY "GEAR DISAGREE" MESSAGE THEN FOLLOWED BY HYD LOW PRESSURE ON NR 3 SYS. QRH FOLLOWED, EMERGENCY DECLARED WITH UNEVENTFUL LANDING. MX INSPECTED SYS FOUND THE NR 3 HYD BALL ATTENUATOR UNION LEAKING. REMOVED AND REPLACED O-RING ON UNION OF THE BALL ATTENUATOR. SYS SERVICED AND PRESSURE TESTED IAW AMM. (K)