What was found
PRIOR TO EITHER LANDING GEAR EXTENSION OR FLAP EXTENSION DURING APPROACH INTO DTW, THE RT HYDRAULIC SYSTEM FAILED. QUANTITY DROPPED TO BELOW 3 QTS AND PRESSURE WENT TO ZERO. COMPLIED WITH COM AND EXTENDED GEAR PER LEFT SYSTEM PROCEDURE. GEAR EXTENDED NORMALLY AND INDICATED ALL 3 GREEN WITH DOORS CLOSED. LANDING WAS UNEVENTFUL AT DTW. CREW DECLARED AN EMERGENCY PRIOR TO LANDING. MAINTENANCE FOUND A FITTING ON THE RIGHT SIDE PRESSURE FOR GEAR UPLOCK LEAKING. TIGHTENED FITTING. LEAK AND OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.