A320
Troubleshooting
Aircraft Equipment Problem Less Severe
Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
An aircraft had an air return for the loss of number 1 engine; green; hydraulic pressure; no loss of fluid. The aircraft was moved to the hangar on day shift for repair. We motored the engine and observed the pressure coming from the pump: it increased to 3000 psi then fell off. The aircraft was moved inside and the cowlings were opened up for inspection of the EDP (Engine Driven Pump). There were no external leaks or external damage to the EDP. We continued to inspect the fluid lines from the pump to the pylon disconnect. It was found that the fluid supply line had become disconnected at the pylon connection; it was further noticed that the locking section of the pylon side of the fluid supply line quick disconnect was not locking to the line side. We suspect the line vibrated off; starving the pump and the loss of pressure. The disconnect; pump; and case drain were replaced.
Maintenance Technician reported loss of hydraulic pressure due to disconnected fluid supply line.