Replace your worn or leaking coolant cap with this Radiator Expansion Water Tank Cap, part number 3B0121321, designed to fit a wide range of Audi models including A1, A2, A4, A5, A6, A7, Q5, and TT. This high-quality replacement ensures proper pressure regulation and coolant system performance, helping prevent overheating and leaks.

Manufactured from durable plastic and tested to meet OEM standards, it’s a direct-fit solution for vehicles with pressurized expansion tanks.

⚙️ Product Features

• 🔧 Part Number: 3B0121321

• 🚗 Fitment: Audi A1 (2010–2018), A2, A4 (2002–2016), A5 (2007–2017), A6 (2010–2018), A7 (2010–2018), Q5 (2008–2017), TT (1998–2014)

• 🧱 Material: High-grade plastic with pressure seal

• 🌡️ Function: Maintains correct coolant pressure and prevents leaks

• 🛠️ Installation: Direct screw-on replacement—no tools required

✅ Benefits

• 🧠 Restores proper cooling system pressure

• 🔄 Direct OEM-style replacement

• 🧩 Compatible with multiple Audi models

• 💼 Ideal for DIY repairs and garages

• 🇬🇧 UK stock with fast dispatch

📦 What’s Included

• 1x Radiator Expansion Tank Cap (3B0121321)