Narrative:

I was informed that on the morning of feb/xa/01, aircraft xyz turned back due to loss of 'B' system hydraulic pressure (quantity full, pressurization zero). A faulty 'B' reservoir check valve was found. Both reservoir check valves were changed, which fixed the problem. Prior to this flight, I performed 'B' check job card x-xxxxx (hydraulic system check and service). During this check, both 'B' pump case drain filters were changed. Leak checks and operation of flaps yielded no problems with the hydraulic system. The taxi crew that took the aircraft to the gate saw no problems either. It is my position that the maintenance I performed had no bearing whatsoever on the incident in question.

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Original NASA ASRS Text

Title: A TECHNICIAN DISCLAIMS CONNECTION WITH OR RESPONSIBILITY FOR THE AIR RETURN FOR LOSS OF 'B' SYS HYD PRESSURE.

Narrative: I WAS INFORMED THAT ON THE MORNING OF FEB/XA/01, ACFT XYZ TURNED BACK DUE TO LOSS OF 'B' SYS HYD PRESSURE (QUANTITY FULL, PRESSURIZATION ZERO). A FAULTY 'B' RESERVOIR CHK VALVE WAS FOUND. BOTH RESERVOIR CHK VALVES WERE CHANGED, WHICH FIXED THE PROB. PRIOR TO THIS FLT, I PERFORMED 'B' CHK JOB CARD X-XXXXX (HYD SYS CHK AND SVC). DURING THIS CHK, BOTH 'B' PUMP CASE DRAIN FILTERS WERE CHANGED. LEAK CHKS AND OP OF FLAPS YIELDED NO PROBS WITH THE HYD SYS. THE TAXI CREW THAT TOOK THE ACFT TO THE GATE SAW NO PROBS EITHER. IT IS MY POS THAT THE MAINT I PERFORMED HAD NO BEARING WHATSOEVER ON THE INCIDENT IN QUESTION.

Data retrieved from NASA's ASRS site as of July 2007 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.