What was found
2 00 INTO FLIGHT WE RECEIVED A LEVEL 1 HYD 3 ELEV OFF ALERT. COMPLIED WITH THE QRH AND NOTICED SYSTEM 3 QUANTITY DECREASING THROUGH 4.0. WE PREEMPTIVELY COMPLETED THE HYD 3 QTY LOW PROCEDURE TO CONSERVE FLUID. ONCE NEAR MEMPHIS WE DECLARED AN EMERGENCY, RESTORED SYSTEM 3 AND EXTENDED THE GEAR. GEAR EXTENDED NORMALLY BUT QUANTITY DECREASED TO 1.6. WE LANDED ON RWY 36L, STOPPED ONTHE RUNWAY AND WERE TOWED TO PARKING. ***EMERGENCY DECLARED*** SERVICED #3 HYDRAULIC SYSTEM RESERVOIR IAW AMM 12-13-02-3. FOUND LOOSE LINE ON HYDRAULIC SYSTEM #3 DUAL BRAKE CONTROL VALVE PRESSURE PORT IN RIGHT WHEELWELL. TIGHTNED LINE IAW AMM 32-44-04-2. BRAKES CHECK GOOD IAW AMM 32-40-00-5. CLEANED UP MESS. AIRCRAFT OK FOR SERVICE.