Date: 201807
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Taxi
Aircraft component: Hydraulic Syst Valve
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Time Pressure
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: Taxi
Result: Flight Crew Returned To Gate; General Release Refused / Aircraft Not Accepted; General Maintenance Action
Contributing factors: Procedure; Incorrect / Not Installed / Unavailable Part; Company Policy; Aircraft
Primary problem: Aircraft

Narrative: Prior to takeoff we received an EICAS 'R TAIL HYD VAL' and a corresponding 'OFF' light on the back auxiliary panel. We notified Maintenance Control and returned back the gate for Maintenance to investigate. QRH specifically says 'L; C; and R Tail FLT CONTROL SHUTOFF SWITCHES MUST BE ON FOR FLIGHT.' We wrote this item up in the logbook. We described to Maintenance what had occurred and the immediately said; Oh it's only a light and let's defer it. They spent an hour and a half trying to put the light out. They did their system checks and each time the light would go out for a brief period then come back on finally staying on. I refused taking the airplane till this item was fixed since we were are at a major Maintenance hub; where repairs could be made. [Local] Maintenance and I got Maintenance Control on the phone and they were extremely pushy for me to take the airplane. This light is an agreement light that shows the valve is either not in its commanded position. They could not definitively tell me where that valve was. They spent more time trying mask the problem with pulling breakers and going down to the ELEC BAY trying to get the light to go out. With each attempt the time interval when the light came on grew shorter with the light finally staying lit continuously. I told Maintenance Control that I am refusing the airplane. They told me they didn't have any parts [at the airport] to fix this. I proceeded to get [another pilot] involved and after lengthy discussion he to agreed Maintenance was only trying to mask the problem to get the plane out. They deferred it but the number they put in the deferral was MEL 27-XX-X. This refers to the valve not the light. The sign off didn't say what they did. [Local] Maintenance was pissed off that I would not take the plane. I asked 'well what's the game plan.' One gentleman told me; who was visibly angry state; we have to replace the valve now. The FO (First Officer) and the two captains we had on the jump seat and I started back the hotel till it was fixed with an advise time of at least 2 hours. About an hour later I get a call from Maintenance Control (different person now) saying the plane would be fixed within the hour. I asked where did they get the part and he said 'oh they had one all along there'. We returned to the plane; valve was replaced and proceed to take the airplane to [the destination] without further incident.




Synopsis: B767 Captain reported returning to the gate due to a 'R TAIL HYD VAL' message.