What was found
OPEN U DURING CLIMB DEPT KORD APPROX 5000 LOUD BANGING NOISE FOLLOWED BY YAW, A/P ENGAGED, LE N1 30%, FUEL FLOW APPROX. 4000PPH, RT ENG NORMAL, LT ENG BACK TO NORMAL. SECOND OCCURRENCE BANGING LOW N1 & FF ON LT ENG EICAS "L ENG HPSOV" ( SOUNDED LIKE COMPRESSOR STALL) TAT 14 DEG. RAN QRH, ENG HPSOV CHECKLIST, NO OTHER OCCURRENCE. RETURNED TO ORD. PERFORMED BORESCOPE INSP PER 767 MM 72-00-00-6 FOR STALL, NO DEFECTS NOTED. HMU REQ R & R PER TSI WRI 72-00/2710. REMOVED HMU IAW MM 73-21-14-4, BREAKERS D25 ON P11 AND E1 ON P6, PULLED AND COLLARED. REMOVAL COMPLETED PLATES FOR HARD LINES MUST BE REMOVED FROM NEW OTHER FASTENERS AND HARDWARE IF REQ. CONT R & I PER AMM 73-21-14-4 THRU INSTALLATION STEP 3,E,(8). DUE TO OTHER MX. CLOSE UP AND HMU TEST STILL NEEDS TO BE ACCOMPLISHED. COMPLIED WITH REMAINING STEPS PAGE 25. STEP F. 1-2-3-4-5 END IAW AMM-73-21-14-4 REF-71-00-00-5-3. COMPLIED WITH TESTS 2-3-5-11. ALSO COMPLIED WITH MAX POWER ASSURANCE IAW AMM-71-00-00-5-3 AND JRH-7-6 AND JRH-4-6 THROUGH 4-11. ALSO COMPLIED WITH MAX POWER ASSURANCE AND BOTH MIN IDLE AND APP IDLE PARAMETERS WITHIN LIMITS REF-JRH AND-AMM-71-00-00-5-3. ALL PARAMETERS WITHIN LIMITS. ALSO COMPLIED WITH FIM-36-10 FAULT TREE 833. OK FOR SERVICE.