What was found
NR 1 ENGINE STRUT OVERHEAT LIGHT ILLUMINATED. NR 1 ENG WAS PROVIDING BLD FOR LEFT DUCT PRESSURE WHICH WAS 20 PSI HIGHER THAN RIGHT DUCT. REMOVED AND REPLACED NR 1 ENGINE HIGH PRESSURE MODULATING AND SHUTOFF VALVE PER MM 36-12-42 PG 401 AND 402. LEAK AND OPER CHECK NORM. RAN 1 AND 3 ENGINE TOGETHER WITH BOTH PACKS ON AT APPROX 65 TO 70 PERCEN, N2 LT AND RT DUCT PRESSURE WAS EQUAL AND STEADY.