What was found
JUST AFTER TAKEOFF FROM PDX, RECEIVED A DUCT LEAK WARNING ON MAP AND UPPER PANEL RIGHT PACK. CONSULTED QRH AND RETURNED FOR LANDING AT PDX. LIGHT WENT OUT ON DESCENT INTO PDX ABOUT 2,000 FT. DURING QRH PROCEDURE WHEN BLEED WAS CLOSED BLUE HYDRAULIC INDICATOR WENT TO EMPTY WITH NO ASSOCIATED WARNING. INVESTIGATED, FOUND BAD WIRE ON THERMAL SWITCH. REPAIRED SAME. FOUND TWO LEAKING CLAMPS AT HEAT EXCHANGER. REPAIRED AND TIGHTENED CLAMPS AND FOUND A DEICE SYSTEM PRESSURE REGULATOR LEAKING. REMOVED AND REPLACED PRESSURE REGULATOR. RAN ENGINES, NO LEAKS. OPS CHECK GOOD AS PER MM 30-10-20. P/N: 38E96-6A, S/N ON: B2407.