Genuine 4G0 121 109S Engine Coolant Overflow Return Hose

The Genuine 4G0 121 109S is an OE engine coolant overflow hose designed for Audi A6 C7 and A7 Sportback models equipped with 3.0 liter TFSI engines. This factory-original connector hose serves as the coolant return line that feeds coolant back to the expansion tank in the vehicle's closed-loop cooling system.

Key Features:

• Genuine VW/Audi OEM part manufactured to original equipment specifications
• Ensures proper coolant circulation between engine and expansion tank
• Designed to withstand high temperatures and cooling system pressure
• Direct replacement for worn or leaking original hose
• Backed by manufacturer's warranty for quality assurance

This coolant overflow hose is engineered to exact OEM tolerances, ensuring a precise fit and reliable performance. Regular inspection of cooling system hoses is recommended, as they can deteriorate over time from heat exposure and coolant contact. Replacing a failing coolant hose helps prevent overheating and potential engine damage.