What was found
SHIP 5652 AFTER DUAL ENGINE START ON THE RAMP, AFT FAS NOTIFIED PILOTS NOTIFIED PILOTS OF VERY STRONG FUEL ODOR. THE SMELL CONTINUED CAUSING FAS TO FEEL A HEADACHE TO OCCUR. PERFORMED QRH 8.4 SMOKE /FIRE/FUMES CHECKLIST. SMELL DIMINISHED AFTER RIGHT PACK WAS TURNED OFF AS PART OF THE CHECKLIST. RETURNED TO GATE. CORRECTIVE ACTION: PERFORMED STEP 1 TO IDENTIFY CAUSE OF FUMES, FOUND FUEL LEAK RUNNING DOWN RIGHT WING AND INTO RT PACK BAY. REF B757 AMM 21-00 . REMOVED DRY BAY FUEL LINE PER B757 AMM 28-22. INSTALLED NEW DRY BAY FUEL LINE PER B757 AMM 28-22. PERFORMED ENGINE RUN, LEAK AND OPS CHECK GOOD. NO MORE ODOR IN CABIN. (6468196)