As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 4 HYD SYS LOSS, RTFL. CREW REPORTS LOSS OF NR 4 HYD SYSTEM, QTY DOWN TO .32, AHM SHOWS LOSS OF QTY AND PRESSURE. SERVICED HYD RAN HYD WITH NO LEAKS NOTED. CHECKS INCLUDED FLIGHT CONTROLS AND LANDING GEAR CYCLING WITH GEAR PINS INSTALLED. SUSPECT AIR IN SYSTEM FROM PREVIOUS NIGHTS WORK.