Genuine OEM Audi Coolant Expansion Tank Cap, part number 2Q0121321A. This cap is a critical component that seals the coolant expansion tank, maintaining the correct pressure within the engine cooling system. It is designed to release pressure if it exceeds 160kPa (23 PSI), preventing damage to cooling components. Made from durable, heat-resistant plastic, it ensures a tight seal and reliable pressure regulation. Using genuine OEM caps guarantees the correct pressure rating and material integrity, preventing coolant loss and engine overheating.

Catalogue entry: COVER black.

Fitted with: 1H0121687A SEAL. RING.