B767 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 250; Flight Crew Total 12000; Flight Crew Type 750
Situational Awareness
Aircraft Equipment Problem Less Severe
Flight Crew FLC complied w / Automation / Advisory; Flight Crew Returned To Departure Airport; Flight Crew Took Evasive Action; General Maintenance Action
Aircraft
In bunk; got told by Flight Attendant to go back to cockpit as we were returning to the departure airport.  When returned was informed by Captain and flying First Officer that we had lost Center hydraulics.  Pressure was zero due pumps turned off and quantity was .16 on screen.  Assisted on Hyd Qty and Loss of C Hyd Sys press checklists.  Alternate flaps; alternate gear extension; along with a little fuel dump (3K) to lower landing weight.  Was in relief pilot seat for over-weight landing.
A B767 First Officer reported a center hydraulic system leak resulting in a return to the departure airport for an overweight landing.