What was found
ACFT WAS ON THE DEPARTURE PHASE OV VDR26, CREW REPORTED A "YELLOW HYDRAULIC RESERVOIR OVERHEAT", PERFORMED AIR TURNBACK, SAFELY LANDING WITHOUT INCIDENT. CREW DEFECT ENTERED ON LP 688766-1, YELLOW HYDRAULIC RESERVOIR OVERHEAT ON DEPARTURE. MAINTENANCE PERFORMED TROUBLESHOOTING AND R & R CHECKVALVE "Y", 3038GM, IAW TSM 29-24-00-810-804A AND AMM 29-24-51 PB401, OPS CHECK GOOD.