N90765301 – Coolant Connector O-Ring for VW Golf Mk5 Mk6 Audi A4 B7 B8 | YDU

Description

This O-ring seals the coolant connector to the engine block or coolant housing, preventing coolant leaks that can lead to overheating and engine damage. Common symptoms indicating replacement include visible coolant weeping or dripping around the coolant connector, a sweet smell from the engine bay, or a gradual drop in coolant level with no visible external leak. Inspect the O-ring whenever the coolant connector is removed during a service or repair. Before installation, lightly lubricate the O-ring with clean coolant or a compatible rubber-safe lubricant to ease fitting and prevent tearing. Ensure the mating surfaces are clean and free of debris before reassembly. No specific torque figure applies to the O-ring itself; refer to the OEM torque specification for the coolant connector fasteners on your specific engine variant, typically in the range of 10–15 Nm for plastic connector housings. Fitment should be verified against your specific engine code prior to ordering, as O-ring dimensions vary across engine variants.