What was found
(CAN) DURING A GROUND RUN THE HYDRAULIC LINE FOR THE NR 2 BRAKE DEVELOPED A HYDRAULIC LEAK CAUSING A LOSS OF SYSTETM B HYDRAULIC PRESSURE. UPON INVESTIGATION OF THE LINE IT WAS DETERMINED THAT THE LINE END FITTING/SLEEVE THAT SEALS AND RETAINS THE LINE B-NUT BECAME SEPERATED FROM THE PRESSURE LINE WITH NO SIGN OF PHYSICAL DAMAGE. BEST DETERMINATION IS THAT THE SWAGE OF THE END FITTING LET GO FROM THE LINE ITSELF.