As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HYD QTY LOSS-LT SYS, AIR TURN BACK. FOUND O-RING CUT ON MANIFOLD ON VERTICAL STABILIZER COMPARTMENT ON LT SYS REPLACED O-RING IAW TASK 20-10--19-404-002. PRESSURIZED SYS, NO LEAK NOTED. SERVICED ALL 3 HYD SYS LEAK CK PERFORMED IAW MM 29-11-00-796-053. OPS CK NORMAL.