Date: 201808
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: Hydraulic System
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Communication Breakdown; Troubleshooting; Confusion; Time Pressure
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Pre-flight
Result: Flight Crew Overcame Equipment Problem; General Maintenance Action
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: During my cockpit checks; I found the Green Hydraulics to be above the maximum quantity limit. I immediately informed my Line Check Airman; (LCA). [The] LCA agreed the Green Hydraulic system was over serviced. I immediately entered a write-up into ACARS; while simultaneously the LCA called Maintenance on the radio as required by the Flight Operations Manual (FOM). After an extended period of time; a mechanic came into my cockpit with an iPad. I greeted him and gave him my name; he did not say his name. He looked at the Hydraulic Quantity page and then looked at his iPad and stated the hydraulics have not been serviced since [last month] and the system cannot make hydraulic fluid. I told him that I still cannot take it like it is. The mechanic continued to give resistance to do anything and turned to my LCA to see if he could convince him the system was not making hydraulic fluid. I then proceeded to [look] in my A320 Flight Manual. My LCA was digesting all the mechanic was trying to say. Then; the mechanic asked me if I could do an engine run while he looked at the Green Hydraulic system below. I told him that is not a normal procedure to assess hydraulic quantity; besides; I have a plane full of people. What are you going to do if the system needs servicing; then what? I have never done an engine run for this issue in [many] years on the Airbus.The mechanic then starred at his iPad and said he has seen this before and once the engine starts; the system will be in the normal quantity range. About then; [another] mechanic came on board and took one look at the hydraulic quantity page and said 'yep; that's over-serviced.' The [first] mechanic began to argue with him. [The second mechanic] then spoke assertively and told the [first] mechanic that [the] iPad is wrong about the last Green Hydraulic service date and it was probably over-serviced on night shift and no one documented the servicing. [The second] mechanic told me he would need to get some tools and rags and would be back. I asked him if he wanted me to remove pneumatic pressure so he could service the Green System. He said 'no; I will service it the way it is.' After an extended period of time; I saw the right main gear door come down. A while later; he comes into my cockpit and said 'yes; I'm going to need you to remove the pneumatic pressure.' I complied.The Green Hydraulic System was serviced and we departed. The long process of draining an over-serviced hydraulic system is problematic and unfortunately all too typical. However; the very few times I have seen it done properly it is done in under nine minutes and usually closer to six minutes. I had an identical maintenance write up [before] and the Maintenance response caused almost a five-hour delay. The mechanics did not remove pneumatic pressure and the drain valve stuck open and drained the entire Green System.




Synopsis: A320 Captain reported an overfilled hydraulics system; leading to some confusion with Maintenance before being serviced correctly.