As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TYS WHILE EN ROUTE FROM IAH TO TYS THE A/C WAS OUT APPROXIMATELY THIRTY MINUTES WHEN THE EICAS GAVE A NR 1 HYD, SYSTEM OVERHEAT MESSAGE FOLLOWED BY 0 PRESSURE INDICATION ON NR 1 SYSTEM. THE CREW FOLLOWED THE QRH PROCEDURE AND LANDED THE A/C AT TYS. MAINTENANCE REMOVED AND REPLACED THE NR 1 HYD MANIFOLD ASSY IAW AMM 27-10-07. REMOVED AND REPLACED THE NR 1 ENGINE DRIVEN HYD PUMP IAW 29-10-03. A/C WAS SERVICED AND ALL OPS CHECKS GOOD AND WAS RELEASED BACK TO SERVICE.