B777 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 250; Flight Crew Total 12715; Flight Crew Type 3597
Communication Breakdown; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew Returned To Gate
Procedure; Aircraft; Human Factors
Towards end of taxi out rt hydraulic quantity 1.20 OF (overfill). Satcom was inop so called ops to call [Maintenance Control]. A mechanic called us back and told us to do a procedure to transfer hydraulic fluid from right system to the center and left systems. We did procedure and rt fluid quantity was reduced to normal. A message then came from [Maintenance Control] to return to the gate to fix the hydraulic problem. We were under the assumption that [Maintenance Control] had directed him to have us do the procedure because I asked for [Maintenance Control] in the first place.
[Report narrative contained no additional information]
B777 flight crew reported unknowingly accepting maintenance direction from the local Mechanic rather than Maintenance Control.