What was found
(CAN) WHILE CLIMBING THROUGH 4500 FT, ENGINE FIRE/WHEEL WELL FIRE BELL RANG. THERE WERE NO FIRE INDICATION LIGHTS ILLUMINATED. THE AIRCRAFT RETURNED TO DEPARTURE. TROUBLESHOOTING WAS PERFORMED BY MAINTENANCE PERSONNEL AND IDENTIFIED THE NR 1 ENGINE PYLON CLAMPS TO THE PRE-COOLER AND NR 1 ENGINE SHUTOFF VALVE. THE CLAMPS WERE REPLACED WITH NEW. ENGINE NR 1 FIRE LOOP WAS ALSO REPLACED DUE TO INTERMITTENT INDICATION FOR FLIGHT CREW AND DURING GROUND TEST. NO FURTHER FAULTS WERE INDICATED AND THE AIRCRAFT WAS RELEASED FOR SERVICE.