Date: 201808
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Parked
Aircraft component: Waste Water Disposal System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: [During] the flight I noticed that the flush was not working. Although I could hear the flush pump running; no water was flowing in the toilet. I added during the flight about two quarts of water (from bottled water) and was able to see water flushing the toilet.Upon landing and parking on a stopover; planned to leave two hours later; while the airplane was unloaded; the lavatory service man approached me and asked if we needed lavatory service.  I told him that we indeed needed the lavatory to be serviced.I was in the galley when the lavatory service man called me and asked me to move our bags away!  I walked back onto the flight deck to see the lavatory overflowing with blue water that was also about 1/2 inch deep in the lavatory itself and the carpet on the flight deck being covered with the same blue water on a surface of about 15 SQ FT.I went downstairs to alert maintenance.Airplane was then cleaned and inspected as water had reached the E & E (Electrical and Electronics) compartment. Engine run-ups were subsequently performed and the airplane was finally cleared to return to service. The delay was only about an hour or so.During the following flight we experienced a series of abnormal events.-EICAS 'LEFT ENGINE BLEED OFF'-EICAS 'LEFT PACK OFF'-EICAS 'AUTOTHROT DISC' (Auto throttle did not reconnect)-EICAS 'AUTOPILOT DISC' (Unable to reconnect any of the autopilots. Tried again five minutes later and were able to reconnect right autopilot for remainder of flight)-NO AUTOLAND appeared on the Autoland Status Annunciator.  (It appeared before the Autothrottle Disc EICAS)-VNAV became inoperative. While in cruise at FL360; VNAV PATH was indicated on the FMA (Flight Mode Annunciator); ATC instructed us to descend; FL320 was selected on the MCP (Mode Control Panel); the button was pushed; we were before TOD; but the aircraft refused to descend. This happened again later on.The airplane performed flawlessly on the previous flight; so obviously the water escaping from the lavatory created all the problems we encountered on the following leg; despite the best efforts from maintenance to clean; check and clear the airplane back to flying status.The First Officer and I were pretty certain that we would encounter some kind of problem on that flight and were not really surprised by the turn of events. But it is difficult to refuse a flight because of a 'gut feeling' and the situation was far from being critical and the flight was otherwise straightforward. I nonetheless made sure that every discrepancy was entered in the airplane logbook to make sure the airplane was fixed properly and to prevent the same situation to reoccur on following flight(s).




Synopsis: B767-300ER Captain reported a number of anomalies occurred after a lavatory spill contaminated the Electrical & Electronics compartment.