Date: 201911
Local time of day: 0601-1200
Location: ZZZZ.Airport, FO
Flight conditions: VMC
Light: Night
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center ZZZZ
Aircraft component: Hydraulic Main System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Second reporter function: Captain; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed As Precaution; Flight Crew Diverted; General Maintenance Action; General Flight Cancelled / Delayed
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: 15 minutes before reaching ZZZZZ waypoint; at FL320; we received a R HYD QTY EICAS message. I asked the First Officer to get the QRH while I checked the status page. Once on the page I witnessed the right hydraulic level stating .43RF. After completing the QRH I called the Flight Attendant to wake up the Mechanic and the other Captain and have them come to the flight deck. Then we sent a message to company via ACARS. While this was going on we were talking to ZZZ and just entered our North Atlantic crossing at ZZZZZ waypoint. We let ZZZ know that we might have to turn around and proceed to our ETOPS alternate; which was ZZZZ1 airport. They told us to keep them advised. Shortly after the other Captain came in and sat at the observer seat while the mechanic sat behind me. I brought them up to speed on the current situation and had the other Captain call company via SATCOM. The Mechanic took a look at the status page and at this time the hydraulic quantity was at .38RF. At the rate of loss I had the first officer tell ZZZ that we would like to proceed to ZZZ1. Moments later we were give a turn to our new destination airport. I then informed the Flight Attendant that we were going to our alternate airport; that it was not an emergency but we did lose one of our hydraulic systems; and that we would be landing in about 30-40 minutes. The Captain sitting at the observer seat advised me that company would like us to perform the Hydraulic System Pressure (R only) checklist in order to prevent damaging the pumps; and hopefully to stop the hydraulic leak. Our mechanic agreed with this plan. After performing the checklist we stopped the leak at .35RF. Moments later; [company] requested that we proceed to ZZZ2 airport instead of ZZZ1. Since we had a lot of fuel to burn; in order to be under max landing weight; and the weather was fine in ZZZ2; we proceeded to our new destination airport after calling ATC. This is when we noticed that the BRAKE SOURCE light was on; which confused all of us since we still had our center hydraulic system working just fine so we should have alternate brakes. We followed the QRH and with the reserve breaks and steering switch in the BRAKE SOURCE light was still on. We then had the company calculate and send us the landing performance for runway 24 into ZZZ2; besides the right side main brakes reaching to 7 before cooling there were no further problems. We were able to taxi off the runway under our own power.


Second narrative: About 2 hours into the flight; while I was on the first crew rest break; the mechanic and I were asked to come up to the flight deck. When we got to the flight deck I sat in the middle observer seat and the mechanic sat behind the other Captain. The crew filled us in on what was going on. They received a R HYD QTY EICAS message and ran the QRH. They sent a message to Dispatch through ACARs informing them of the problem; and also let ZZZ know that we might have to turn around and head to our ETOPS Alternate; which was ZZZ1. I looked at the status page and saw that the right hydraulic quantity was now at .38RF. We decided that with the loss of the Right Hydraulic System it was best to turn around and head to our ETOPS Alternate. The First Officer called ZZZ and let them know that we would like to proceed to ZZZ1. The Captain called the Flight Attendants and let them know that we were now going to our alternate airport; that it was not an emergency but we had lost one of our hydraulic systems; and we would be landing in about 30-40 minutes. We were given a turn toward ZZZZ1 shortly after crossing our North Atlantic entry waypoint ZZZZZ. During this time; I had made a call to company via SATCOM. Dispatch; Maintenance Control; and a Duty Pilot were all on the call. I informed them what was going on; and Maintenance Control said that they would like us to perform the Hydraulic System Pressure (R Only) checklist to prevent damage to the pumps and possibly help stop the hydraulic leak. Our mechanic on board also agreed with this plan. After we completed the checklist; the hydraulic quantity read .35 RF and remained at this level the rest of the flight. Dispatch also said that they would like us to proceed to ZZZ2 because of better maintenance and facilities. The weather was fine in ZZZ2 and it would help us burn fuel to be under landing weight; so we called ATC and proceeded to ZZZ2. Then we noticed that BRAKE SOURCE light was on. This was odd because we still had our center hydraulic system working normally so we should have alternate brakes. We followed the QRH checklist and pushed the Reserve Brakes and Steering Switch but the BRAKE SOURCE light remained on. We then had the company calculate and send landing performance for Runway 24 into ZZZ2; and we completed all other appropriate checklists for landing. After contacting ZZZ2 Tower they asked us what our maintenance problem was. We let them know it was a hydraulic leak and the breaking system was affected; but we should have had no problem stopping the aircraft on the runway. They informed us they would have the fire vehicles standing by to check for fluid on the runway that would need to be cleaned up if it was still leaking and keep and eye on our brakes. We landed safely in ZZZ2 with no other problems and were able to taxi off the runway and to the gate under our own power. The right side main brakes did heat up to 7 before cooling.I thought everything went pretty well; we landed safely; and used good CRM. If I could go back and do one thing differently; I would have stopped on the runway; not taxied; and had operations tow us to the gate. The brake source light didn't go out after the Brake Source QRH checklist. The checklist says this indicates we only had brake accumulator pressure. Even though we had normal center hydraulic system pressure which should give us pressure for alternate brakes; it would have been safer to not taxi the aircraft after landing.


Synopsis: B767 Captain reported that a hydraulic system failure resulted in a diversion.