Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Communication Breakdown; Training / Qualification
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft
Arrived at aircraft. I reviewed the Aircraft Maintenance Logbook (AML) to verify what I had already reviewed on my IPAD. The aircraft had three MEL's: Auto-brakes inoperative; Auto speed brakes inoperative; and External power inoperative. I then found an open write up for the Anti-skid system; and called maintenance to address the issue. (This was the first flight of the day; aircraft was in ZZZ all the previous night).Maintenance arrived; and I showed them the open write-up and gave them the logbook. I then discovered that the B system hydraulic was at 69% with RF displayed. I again called maintenance to address this issue. The technician showed up and filled the system to 88%. I told the technician that I did not put the discrepancy in the AML; and if he wanted me to; I would get the AML from the other maintenance technicians and make an appropriate entry. He said; it's okay. We then pressed on with the other issues. I never made a HYD B low" entry into the AML. Upon landing ZZZ1 and accomplishing our post flight duties; I again noticed that hydraulic system B was at 69% with the RF displayed. I made an AML entry and called Maintenance Control regarding the issue. I then left the aircraft and debriefed the oncoming Captain on all of the above issues. I later called the oncoming Captain and was told that during trouble shooting in ZZZ1; a hydraulic leak was discovered in one of the wings.With the many MEL's and the newly discovered maintenance issues; I failed to make an AML entry regarding the low system B hydraulic quantity prior to having it serviced. I also allowed it to be serviced without an AML entry.Suggestions: Maintenance could clear MEL's on overnights and service low fluid quantities. They could also investigate low fluid quantities that are out of the ordinary."
B737-800 Pilot reported failing to make proper AML entries for hydraulic system maintenance event.