What was found
DURING ROLLOUT ON LANDING, NOSE WHEELS AND RT MAIN GEAR WHEELS DEPARTED HARD SURFACE OF RUNWAY. LINE MAINTENANCE INSPECTED AIRCRAFT AND DETERMINED AIRCRAFT COULD BE SAFELY RESTORED TO RUNWAY. PINNED GEAR AND SUBSEQUENTLY AIRCRAFT WAS TOWED TO GATE TO DEPLANE PASSENGERS AND FURTHER INSPECT AIRCRAFT LANDING GEAR SYSTEM. FOUND LANDING GEAR ISOLATION VALVE HAD FAILED. REPLACED ISOLATION VALVE, REPLACED HYDRAULIC FILTERS, PERFORMED HARD LANDING INSPECTION AND NO DAMAGE FOUND.