What was found
(CAN) DURING APPROACH, LANDING GEAR FAILED TO DEPLOY. EMERGENCY SYSTEM ACTIVIATED. ACFT LANDED WFI. MAINTENANCE INSPECTION FOUND THAT THE LANDING GEAR EXTENSION SOLENOID, MAGNETIC SELECTOR VALVE, PART OF MANIFOLD, ON THE HYD SUPPLY MANIFOLD WAS UNSERVICEABLE. HYDRAULIC SUPPLY MANIFOLD WAS REPLACED, GEAR SWINGS WERE COMPLETED AND THE ACFT WAS RETURNED TO SERVICE.