What was found
DURING FLIGHT 3550, AT 29,000 FT, CREW RECEIVED A YELLOW HYDRAULIC SYSTEM HIGH TEMPERATURE WARNING. RAN QRH WHICH CALLED FOR YELLOW SYSTEM SHUTDOWN. HIGH TEMP WARNING EXTINGUISHED WITHIN 2 MINUTES AFTER SYSTEM SHUTDOWN. MAINTENANCE PERFORMED YELLOW AND GREEN HYD. SYSTEM CHECK OPS CHECK FOR 20 MINUTES. ALL PRESSURED GOOD ON EDP, PTU, AC PUMP. NO HIGH TEMPS WARNINGS. NO LEAKS NOTED FO SYSTEM. REPLACED YELLOW SYSTEM HYD TEMP SWITCH PER AMM 29/33-11-201, P/N HE 83273-1, S/N ON 1368TW, S/N OFF 1304TW. NO LEAKS NOTED.