What was found
CAPT ADVISED LOSS OF SYS "A'' HYD QTY. (U147655) LOCKED L/P UNLOCKED FOR UPDATE LOG PAGE LOCKED AFTER MX UPDATE VERBALLY NOTIFIED BY FLIGHT CREW HYD PAGE DISLAYED 20% HYD QTY IN FLIGHT , THEREAFTER HYD SIX PACK FLASHED HEARD NOISE AND VIBRATION , BLOCKED ON THE GATE HYD PAGE DISPLAYED 44% RF . APPEARS EVIDENCE IN WHEEL WELL AREA OF LEAKS . T/S REQUIRED. UNLOCKED FOR SIGNOFF DURING #1 ENG RUNS NOTICED HYD FLUID COMING FROM HYD SYS A MODULAR PACKAGE ASSY HYD PRESSURE SYSTEM CHECK VALVE, REPLACED CHECK VALVE ORING RAN #1 MOTOR OPS CHECKS GOOD REF AMM 29-11-71. PICTURES