B767-300 and 300 ER
Flight Crew Instrument; Flight Crew Commercial; Flight Crew Multiengine
Flight Crew Last 90 Days 180; Flight Crew Total 11000; Flight Crew Type 2000
Situational Awareness
Aircraft Equipment Problem Less Severe
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
Sometime after passing ZZZ1 we had a C HYD SYS PRESS EICAS caution. We ran the QRH and could not establish normal pressure to the Center HYD System. We noted there was full center HYD quantity on the lower EICAS screen. The C HYD PRESS checklist required us to alternately extend the flaps and gear; so we decided [advising ATC] was appropriate. We contacted Flight Control and talked to Dispatch and Maintenance; informed them of our intention [to request priority handling]. With the concurrence of Flight Control; we decided [to divert].The failure of the main hydraulic system and resulting single power source to items such as gear; flaps; stab trim and left inboard ailerons; this followed most appropriately with the AOM (Aircraft Operating Manual) 'nearest suitable airport' intent. Based on familiarity with ZZZ and their long runways; the Dispatcher concurred it was the best choice and had good weather; so I elected to land there. We got an arrival for the new destination. It had been the FO (First Officer) leg; but we decided to switch roles; with the Captain flying and FO as PM (Pilot Monitoring). When we started configuring the flaps we had a LE Assym EICAS - we reviewed the LE Assym checklist; and rechecked everything and noted via our phone cameras that the LE slats were definitely in their proper positions.We contacted Flight Control again and talked to Maintenance and [Engineer] to discuss options and see if we were missing something; and based on all available information we had; we determined the aircraft slats were in the takeoff position. We also noted the LE Assym EICAS message vanished on its own. The Alternate Flap and Gear Extension operated normally. ZZZ had CFR (Crash Fire Rescue) standing by for us.On short final (approximately 200 ft.) we had another odd thing happen - the PLI (Pitch Limit Indicator) started to move erratically and jump up and down and the stick shaker briefly activated. The aircraft was stable and on flaps 20 ref speed of 140 (I added 5 more kts. for a VApp of 145) with very light winds. The PLI erratic movement made no sense; but I increased power and lowered the nose a bit; and we touched down uneventfully. CFR checked the aircraft out once we pulled off the runway and they noted no hydraulic leaks or other fluids coming out of the aircraft. We were light enough that only moderate braking was used. We took plenty of time to review checklists and make sure we didn't miss anything. We cannot explain the spurious PLI movement or the transient LE Assym EICAS message.
B767-300 Captain reported multiple EICAS messages and systems failures; resulting in a diversion and emergency landing.