Keystone HY3014108 Coolant Reservoir Overflow Tank with Cap Assembly

The Keystone HY3014108 is a direct-fit OEM-replacement coolant reservoir assembly designed for the Hyundai Sonata and Kia Optima. Also known as a coolant overflow tank or expansion tank, this component plays a critical role in the engine cooling system by capturing and storing excess coolant fluid as it expands under heat, then returning it to the radiator as the engine cools.

This assembly ships complete with the reservoir cap, so no additional hardware is needed for a straightforward, bolt-in installation. It is engineered to match the original factory specifications, replacing OEM part number 25430-3C050.

Key Features:

• Complete assembly — includes reservoir tank and cap
• Direct OEM replacement — engineered to match factory fit and function
• Durable plastic construction designed to withstand underhood heat and vibration
• Replaces Hyundai OEM part number 25430-3C050
• Aftermarket part number: HY3014108

This coolant reservoir is a reliable solution for restoring proper cooling system function and preventing coolant loss or engine overheating caused by a cracked or damaged original tank.