What was found
DURING CLIMB, PASSING APPROX FL280 HAD INDICATIONS OF MANIFOLD FAILURE INCLUDING 'AIR SYS 1 OFF' & 'AIR SYS 2 OFF'. MASTER CAUTION/WARNING EAD ALERTS LASTED ONLY SPLIT SECOND. DIVERTED. PERFORMED DECAY CHECK OF PNEUMATIC SYSTEMS 1 & 2. INDICATIONS NORMAL. REF JRH. PERFORMED RTS TEST ON PSC 1& 2. NR 2 PSC FAILING HIGH STAGE TEMP SENSOR. TROUBLE SHOT PER FIM 36-23. THIS FAULT HAS OCCURRED FROM AN OVERHEAT DETECTION LOOP 1A/1B IN FWD LT TUNNEL STARTING IN CENTER ACCESSORY BAY. FOUND LOOSE CLAMPS ON 1-2 ISOLATION AIR SYSTEM VALVE, BLOWING HOT AIR DIRECTLY ONTO THE LOOPS. SECURED CLAMPS & LEAK CHECKED GOOD. PERFORMED DECAY CHECKS OF THE NR 1 & 2 PNEU SYS PER MM 36-00-01-5 CHECKED GOOD. ALSO PERFORMED AIR SYSTEM TEST PER MM 36-23-01-5 CHECKED GOOD.