What was found
HYD PUMP 1R OFF DISPLAYED DURING CRUISE AT FL280. PUMP 1R FAULT LIGHT ON HYD OVERHEADD ILLUMINATED. HYD SYS 1 TEMP INDICATED 94 DEG C. SUBSEQUENTLY HYD 1 OFF ALERT AND NR 2 AUTOPILOT DISCONNECT. RETURNED TO RPLB. TEMP DECREASED TO 79 DEG C, WHEN ON APPROACH. SLATS EXTENDED, BOTH PUMPS ON, NORMAL FLAP AND GEAR EXTENSION. NO A/P WITH LOWER YAW DAMP INOP. FACT: REMOVED AND REPLACED 1L AND 1R EDP AND CASE DRAIN FILTERS. FLUSHED HYD SYSTEM. OP/LEAK CHECKS GOOD ON ENGINE RUN.