As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A SYSTEM HYDRAULIC SYSTEM DECREASED TO 1/4. INT LOW HYD LIGHT ON NR 1 ENG NR CAME ON STEADY ON TAXI IN. MONITORED VERY SLOW FLUID LOSS DURING 1/2 TO 1/4 WENT ABOVE 1/4 WITH GEAR EXTENSION. SECURED FITTING ON A SYSTEM FILTER MODULE, LEAK CHECKS GOOD.