What was found
FLT#787, JFK-SXM. (AIRCRAFT PERFORMED AN AIR TURN BACK TO JFK) 'ENG 1 ABNORMAL PRESSURE SPOKE WITH MARIO IN MCC RAN QRH & RESET GUIDE NO JOY. ENG 1 44 PSI 190. ENG 2 48 PSI 190. THIS HAPPENED IN CRUISE AROUND 30,000; REF L.P. 3737797, ITEM 1 (REMOVED AND REPLACED OVER PRESSURE VALVE PER AMM 36-11-53)FOR REMOVAL AND REPLACEMENT OF #1 ENG OVERPRESSURE VALVE. ITEM #2 (OPS CHECK & LEAK CHECK OF #1 ENG OVER PRESSURE VALVE REF AMM 36-11-53 OK) FOR OPS CHECK & LEAK CHECK, & 3737798, ITEM #1 (CONDUCTED HIGH POWER ASSURANCE TEST II PER AMM 71-00-00-710-013-C.TEST PASSED, NO BLEED PRESSURE ISSUES.) FOR HIGH-PRESSURE ASSURANCE TESTS. ALL TESTS PASSED WITH NO FAULTS.'