EMB ERJ 135 ER/LR
Maintenance Airframe; Maintenance Powerplant
Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Manuals; Chart Or Publication; Human Factors; Aircraft
It was brought to my attention that I may have routed the capillary lines incorrectly on an EMB-135 aircraft's oxygen bottle during a C-Check at ZZZ using Work Card (W/C) XXX-06 for completing an [Oxygen] Leak Check. I was shown I [had] completed installation of the capillary lines in September 2013; by a Manager in October 2013. I must have inadvertently connected the capillary lines incorrectly. I was told by Manager that the EMB-135 aircraft's oxygen bottle pressure gauge kept a good pressure reading; but because of the capillary lines being installed incorrectly the Oxygen bottle level drained without knowing. [Recommend] clarifying proper installation of lines on Work Card (W/C) and have a better Functional Check to verify installation.  The W/C picture of the oxygen line installation figure may need to be clarified to show the correct installation of all lines. Found while aircraft in service at gate.
An Aircraft Maintenance Technician (AMT) was informed he may have incorrectly routed the capillary lines to a Crew Oxygen bottle on an EMB-135 aircraft during a C-Check; causing the oxygen bottle to drain without knowing.