What was found
DURING THE CLIMB, NOTICEABLE SPLIT IN THE EPR AS THEY CLIMBED ABOVE FL 250. AT CRUISE AT FL 330 THERE WAS A .25 SPLIT IN THE EPR WITH THE N1 MATCHED. THE EPR WAS LOWER ON THE NR 1 ENG WITH THE N1S MATCHED. WITH THE EPRS MATCHED THERE WAS A 9% DIFFERENCE IN N1S. THE CREW CONTACTED DISPATCH & MX CONTROL. THE DECISION WAS MADE TO RETURN. WITH ICE PROTECTION OFF LT & RT ICE PROTECTION TEMP HIGH LIGHTS CAME ON & THEN OFF. THE PROBLEM WITH THE ENG SPLIT WAS LESS PRONOUNCED AFTER THEY DESCENDED FOR LANDING. FOUND NR 2 ENG PT2 LINE RUPTURED. R & R PT2 LINE IAW AMM 71-00-00-4-1 3B 40. LEAK CHECKED SYS, FOUND SYS SATISFACTORY, NO DEFECTS NOTED IAW TC 77-071-002 & 77-072-002.