Date: 201812
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: Citation Latitude (C680A)
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
ATC / advisory: Center ZZZZ
Aircraft component: Hydraulic System
Component problem: Malfunctioning
Reporter organization: Air Taxi
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Confusion
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: While climbing out through 37;000 feet we received a hydraulic pressure low right EICAS message several times; shortly thereafter we received a hydraulic volume low message. The climb was arrested and the appropriate checklists were initiated. We determined it would be necessary to divert to a suitable airport and initially I chose ZZZ because it was directly off the left wing and the weather appeared to be good. ATC issued us a clearance to head toward ZZZ. During descent it was realized that the aircraft was over maximum landing weight so after speaking to dispatch and a chief pilot; I made the decision to proceed to ZZZ1. Upon arrival we requested a hold over ZZZ2 VOR to continue reducing the fuel load; review and complete checklists; complete briefing the passengers and securing the cabin for landing.After holding for approximately 25 minutes we configured the aircraft and proceeded to execute a visual approach to runway XXL. On the base leg as I slowed to approximately 135 kts I noticed the autopilot was holding the control yoke to the right approximately 45 degrees. I believe at some point we did receive a message to trim the wing to the right. I brought the condition to the attention of [the First Officer] who was now the pilot monitoring. I disconnected the autopilot and the aircraft began to turn left uncontrollably with the control yoke pulsing to the left as both of us tried to hold a right input that would slow down our left turn. Not knowing what had caused our hydraulic issue and now our left turning problem I asked the PNF (Pilot Not Flying) to disconnect the flight controls.This action did resolve the pulsing issue although the aircraft still had a tendency to turn to the left it was manageable if we kept the airspeed around 130 knots. The PNF managed the throttles while I flew the aircraft.The landing itself was uneventful; I used the emergency braking system to bring the aircraft to a stop. The PNF opened the door and coordinated with [ground personnel] to chock the aircraft as well as helping the passengers evacuate. After speaking with [ground personnel] and inspecting the aircraft it was decided to load up the passengers; start the APU and have a tug tow us to [the FBO.]Suggestions: I feel that everything up until the flight control issue was handled very well and felt very much like situations we train for in the simulator. In hindsight knowing that the flight controls on the Latitude are not hydraulic the only thing I can think of that might have caused our turning issue may have been the spoilers floating with no hydraulic load and possibly the pulsing we fought was feedback through the spoiler mixing box. I do not recall any checklist cautioning or bringing attention to this type of condition. I do believe the fuel was fairly balanced upon landing.




Synopsis: CE-680 Captain reported a hydraulic system malfunction during cruise and subsequent diversion.