What was found
AT 2354Z NOTED HYD 3 ELEV OFF, COMPLIED WITH QRH, DECREASING HYD 3. DECLARED EMER & DIVERTED. HAD ACFT TOWED FROM RAMP ENTRY BLOCK IN WITH 1.6 GAL HYD 3. NORMAL APPROACH, CONFIGURATION & LANDING. AT LT MLG, FOUND LOOSE B-NUT AT MLG HYD ACTUATOR BALANCE TUBE, AT TOP OF TUBE, WHERE TUBE FITS INTO UNION, NUT WAS FINGER TIGHT, NUT IS PAINTED WHITE, TIGHTEN NUT. TOPPED OFF NR 3 HYD SYS. OPERATED SYS, NO LEAKS PINNED GEAR. OPERATED GEAR HANDLE TO UP POSITION, NO LEAKS. REPEATED LEAK CHECK 3 TIMES, NO LEAKS. ACFT OK FOR SERVICE.