What was found
AIR MANIFOLD NR 2 FAIL, PERFORMED DECAY CHECK IAW AMM 36-00-02-5 & 36-00-01-5 WITH APU & NR 2 ENG, BUT STILL FAILED. CHECKED NR 2 PACK FLOW CONT VALVE, FWD, CENTER & BULK CARGO BAY JET PUMPS, SHUTOFF VALVES & DUCTING, NR 2 START VALVE & DUCTING, NR 2 ENG BLEED VALVE, PRESSURE REGULATOR, THRUST REVERSER OVER PRESSURE SHUTOFF VALVE, MOTORCYCLE VALVE & DUCTS, NO LEAK NOTED. WHILE NR 2 MANIFOLD WAS PRESSURIZED, IN THE PROCESS OF CHECKING THE PRE COOLER ABOVE NR 2 ENGINE FOR LEAKS. COMPLETED INSTALLATION OF NR 2 ENGINE PRECOOLER ASSEMBLY IAW MM 36-12-01-4, LEAK CHECKED GOOD ON GROUND IAW MM 36-10-00 & 36-13-01-4, NO LEAKS NOTED, ACFT OK FOR SERVICE.