What was found
SFO - ON TAKEOFF, HYDRAULIC CAME DOWN AND GEAR TOOK LONGER THAN NORMAL TO RETRACT. CONTINUED TO CLIMB OUT, THE HYD FLUID LEVEL CONTINUED TO COME DOWN CONFIRMING A LOSS OF HYD FLUID OR PRESS. CHECKLIST, THE LOSS STOPPED. DECLARED A HYD EMERGENCY, DUMPED FUEL. HYD FLUID STAYED ABOVE STANDPIPE AND AUXILIARY PUMP PRESSURE WAS NORMAL. FOUND LOOSE B-NUT AT PRESSURE OUTLET OF NR 2 ENG DRIVEN PUMP, RESECURED B-NUT, SERVICED RESERVOIR IAW DC-8 MM CHAPTER 12-30-1, BLEED HYD SYSTEM, RAN NR 2 AND NR 3 ENGINES. NO LEAKS NOTED AT THIS TIME. (X)