As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT AT 29K FEET WE LOST HYDRAULIC SYS B FLUID WENT TO ZERO AND TOTAL LOSS OF PRESSURE / [01] REF TTG8Q00DVGLL ALT BRAKE SELECTOR VALVE LEAKING. MT 729-PPRD-01-01 HYDRO SYSTEM FLUSH / FILTER R/R B SYSTEM. NO METAL OR DEBRIS NOTED. TTG8Q00DVGR3 ' B ' EMDP R/R; TTG8Q00VGR5 #2 EDP R/R; SYSTEM RESTORED NO LEAKS NOTED.