Date: 201410
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: MD-83
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: Main Gear
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Pre-flight
Result: General Flight Cancelled / Delayed; General Maintenance Action; General Release Refused / Aircraft Not Accepted
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: During my preflight exterior inspection I noticed that there was hydraulic fluid on the pavement just below the right main gear strut. I also observed a leak coming from the strut aft on the inboard side. I entered my discovery as a discrepancy into the logbook. After notifying my dispatcher I was transferred to Maintenance (MX) control who informed me that a mechanic would come out. After a few minutes a mechanic showed up and said that he did not see any leak on the right main gear strut. I showed him the pictures that I took during my walk-around and pointed out the leak. He disappeared and a few minutes later a second mechanic came up to tell me that it was not a hydraulic leak but just grease from when they serviced the gear. Again I disagreed; showed him the pictures and told him that I touched the fluid with Latex-gloves which revealed a clear reddish fluid not consistent with grease. Also; I showed him the origin of the fluid on the strut which was not near a grease point. He left the cockpit and at which time I received the logbook back. My write-up was signed off as 'No leak found'. Obviously I had an issue with that. I recalled the mechanic (a third one; not the same as the first 2) and asked why it was signed off as no leak found when I had actually shown them where the leak was. He replied that they had wiped off the strut; observed it for 20 minutes and did not find any 'NEW' leaks. I told him that this is what I would have expected to see in the corrective action box rather than the 'No leaks found' comment which makes me look like I was imagining things. He said that this is how they signed it off and if I had a problem with that I should contact MX control. I said that I will take the airplane as is; but that I still would prefer the logbook to show what action really was performed the next time around (Backing my view on that issue are the comments made by MX in flight following [system] stating the steps they did to clear this discrepancy. It's in [flight following system] but not the logbook. Why?). As we were ready to push when the lead Flight Attendant (FA) called me up regarding a sick passenger on board. We decided to have the gate agent contact Medlink in order to get guidance on how to deal with the sick passenger. While this was going and since I had some spare time I decided to re-inspect the right main gear strut. Even though the airplane had not moved yet I again observed a leak on the strut. I called dispatch; the duty pilot and MX control (all on a phone-patch at the same time) and informed them that I would have to put that back into the logbook as a discrepancy. Soon after the call the same mechanic who handed me the logbook (the third one) came back up into the cockpit; told me that after a hard landing when the gear moves some of the O-rings can become unseated and that this would be normal. I said that is fine with me as long as it is acknowledged that it is leaking and that a certain MX procedure is followed assuring the pilots that a certain leak (drops per minute; quantity or such thing) is acceptable. I told him that I would not accept a sign off stating that no leak was found. In a rather condescending voice he belittled me by saying that he will sign it off and make an addition to the sign off explaining how the gear works. I do know how the gear works....it might be him who needs remedial training on how a leak looks like. I did not say that in order to remain professional though. The decision was made to deplane and switch airplanes. I still do not know why suddenly MX changed their mind about the airworthiness and found the airplane not dispatchable; but I informed the gate agent of the decision and we deplaned. What I find very odd is that the MX comments in [flight follow system] say that even the second time around they did not find any leak; despite the photographic evidence to the contrary; but still swapped airplanes to do an inspection and possible repack of the strut.Corrective actions: MX needs to pay closer attention to what the pilots are saying. It is incomprehensible to me how 3 mechanics can't find a leak that was that obvious and then proceed to tell me that the source is something that it wasn't (how can they mistake hydraulic fluid with grease?). Also; if a corrective action is performed it should be reflected in the logbook. Fixing (or trying to fix) something and then then signing it off as if it had never existed in the first place is just wrong. Also; why was the plane taken out of service after I refused the sign-off as 'no leaks found'? All I wanted was a comment like 'leak within tolerance' or similar. Unless of course a leak of any kind is not acceptable; but then they should not have just wiped it off and re-dispatch the plane in the first place.




Synopsis: MD-83 Captain reported that the aircraft was pulled out of service after three attempts to inform Maintenance of a hydraulic leak from the right main landing gear. The Captain was not satisfied with the initial logbook write-up by Maintenance.