B757-200
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 50; Flight Crew Total 11000; Flight Crew Type 5000
Human-Machine Interface
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance
General Maintenance Action
Human Factors; Aircraft
[We] got briefed on inbound log items from Captain bringing the aircraft in. When I stepped on the aircraft I saw two mechanics that appeared to be working on the cabin items. I put my bags in the cockpit and turned to see the mechanics leaving the aircraft. I was told by my Purser that the Mechanic told her all the items were cleared. I then ran out to the bridge to try and catch the Mechanic because it was obvious he wasn't going to debrief me. When I asked him for a maintenance status he gruffly responded everything was fixed. I returned to the cockpit and began my preflight. When I reviewed the Maintenance Release I discovered that the fix for the Center Hydraulic System Pressure light inoperative was 'cycle and cleaned switch message clears'. When I looked at the overhead panel I found the C Hydraulic System Pressure light out with both electric pumps off. I tested the lights and the System Pressure light worked properly. I also reviewed the EICAS messages and discovered the C Hydraulic System Pressure not enunciated. I wrote the system up again and contacted Maintenance. The Mechanic came to the cockpit. I pointed out the overhead panel and lack of system pressure light. He then went about pulling the annunciator light switch out and spraying it with a cleaner. The light still did not illuminate; but did test good. The mechanic left and came back with a MEL for deferral. He showed me the deferral and asked if I would be ok with going with the light deferred. I told him I didn't believe we could comply with the deferral because the last step in the MEL required the EICAS to indicate C Hydraulic System Pressure and it did not. That was the moment the mechanic understood what the true problem was. The light was working properly. I'm frustrated Maintenance did not see or understand the problem and attempted to defer a light when in fact there was a systems problem that needed to be addressed.
B757 Captain describes a maintenance sign off for a faulty Center Hydraulic System pressure light that is actually caused by a faulty pressure sensor which is not addressed by Maintenance.