Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Situational Awareness
Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Maintenance Action; General Flight Cancelled / Delayed
Aircraft; Environment - Non Weather Related; Human Factors
We were beginning the first leg of our trip for the day. My crew and I were boarding the aircraft that had just arrived. I could smell of the distinct odor of hydraulic oil at the door of the aircraft. The smell was throughout the cabin and flight deck. Maintenance was servicing the blue hydraulic system. I went downstairs to talk to the mechanics about the logbook write up from the previous crew and get some fresh air; so I could verify my observation. I went back to the flight deck; the odor was still prevalent; so I turned off the APU bleed air; stopped boarding; asked the boarded passengers to go back to the boarding area. Only about a dozen or so had boarded. Then told the rest of the crew to leave the aircraft.Cause: I don't know; there was previous write ups or servicing of both blue and yellow hydraulic systems. I would suspect that had something to do with it.Suggestions: This has been a high-profile ongoing problem; I don't know.
A319 Captain reported hydraulic fluid type smell during preflight and boarding.