A B757-200 EICAS alerted left hydraulic press and rudder ratio. The QRH was completed and due to unu...

Narrative:

During cruise we experienced a left hydraulic system low pressure alert on the EICAS. We followed the QRH; backed it up with a call to maintenance; due to unusual secondaries (status page showed normal pressure; and when we shut off pumps; per the QRH; the pressure indication went up.) we decided to divert and made preparations and notified dispatch and ATC. The following was a short and uneventful arrival. We completed all checklists appropriate and were met at the gate by company and airfield rescue and fire fighting representatives. We deplaned and the jet was taken out of service for the remainder of the day. This aircraft has had multiple repeat hydraulic and electrical write-ups. Possibly a deeper look into the cause of these repeats is needed.

Original NASA ASRS Text

Title: A B757-200 EICAS alerted L HYD PRESS and RUDDER RATIO. The QRH was completed and due to unusually high system pressure with both pump switches OFF; an emergency was declared and the flight diverted to a nearby airport.

Narrative: During cruise we experienced a LEFT HYDRAULIC SYSTEM LOW PRESSURE alert on the EICAS. We followed the QRH; backed it up with a call to Maintenance; due to unusual secondaries (status page showed normal pressure; and when we shut off pumps; per the QRH; the pressure indication went up.) We decided to divert and made preparations and notified Dispatch and ATC. The following was a short and uneventful arrival. We completed all checklists appropriate and were met at the gate by company and Airfield Rescue and Fire Fighting Representatives. We deplaned and the jet was taken out of service for the remainder of the day. This aircraft has had multiple repeat hydraulic and electrical write-ups. Possibly a deeper look into the cause of these repeats is needed.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	912019
Time
Date	201009
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Hydraulic Main System
Person 1
Function	Pilot Flying First Officer
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical

A B757-200 EICAS alerted left hydraulic press and rudder ratio. The QRH was completed and due to unusually high system pressure with both pump switches off; an emergency was declared and the flight diverted to a nearby airport.