What was found
ON CLIMBOUT, NR 1 BLEED TRIP OFF LIGHT ILLUMINATED, RAN QRH LIGHT EXTINGUISHED BUT RETURNED. RIGHT DUCT PRESSURE AT 55 PSI & LEFT AT 35 PSI BEFORE BLEED TRIP OFF LIGHT REMOVED AND REPLACED NR 1 ENG PRECOOLER CONTROL VALVE SENSOR PER MM 36-12-03. OPS CHKS GOOD ON HIGH POWER RUN. LEFT DUCT PRESSURE AT 35 PSI AND RIGHT DUCT PRESSURE AT 42 PSI. OK FOR SERVICE. ROTABLE PARTS CHANGE WAS INDICATED - TT # 1477642 SN OFF 05290 TT # 1013337 SN OFF 07914 SENSOR, PRECOOL OFF 29-3626-9-9001 5290 ON 29-3626-9-9001 6687 VALVE, PRECOOLER OFF 29-3617-9-0001 7914 ON 29-3617-9-0001 1991.