What was found
LANDING GEAR MADE AN EXTREMELY LOUD NOISE WHEN IT WAS LOWERED. A BANG WAS HEARD THROUGHOUT THE AIRPLANE. WHILE TAXIING, BRAKES CHATTERED AT SLOW TAXI SPEEDS. CENTER GEAR WAS FOUND TO HAVE LOST ALL AIR AND FLUID. FOUND CENTER LANDING GEAR DIAPHRAGM PACKING BLOWN. ALSO, AN EXTRA RETAINER WAS FOUND IN THE PACKING GROOVE. REPLACED THE PACKING, ALL STRUT SEALS AND RE-ASSEMBLED THE GEAR.