What was found
DURING CLIMB HAD A DUCT PRESSURE SPLIT IN EXCESS OF 20 PSI. CLIMB AT FLIGHT LEVEL 350 N1 100.9 PERCENT WING & ENGINE ANTI ICE OFF ISOLATION VALVE AUTO PACK SWITCHES AUTO BLEED AIR SWITCHES ON LEFT BLEED AIR DUCT PRESSURE 42 PSI RIGHT BLEED AIR DUCT PRESSURE 21 PSI. PERFORM ENG NR 2 BLEED AIR SYS HEALTH CK REF MM 36 11 00 NO DEFECTS NOTED. PERFORM FIM TASK 38 10 00 STEP F(1) THRU (33)A NO DEFECTS NOTED. REPLACED 450 THERMOSTAT REF MM36 11 05 AND PRECOOLER CONTROL VALVE SENSOR REF MM 36 12 03. NO LEAKS NOTED. PERFORM ENGINE BLEED OPS CHECK REF MM 36 11 00 710 801. OPS CHECK GOOD.