URO 1J0121321B Engine Coolant Reservoir Cap

Engine Coolant Reservoir Cap for Audi and Volkswagen

This URO engine coolant reservoir cap is built for direct replacement on select Audi and Volkswagen cooling systems. It matches OE cap dimensions for proper fit on original and aftermarket coolant recovery tanks, with heat-resistant materials and a factory pressure-tested design.

Key Features

• Direct-fit engine coolant reservoir cap for select Audi A3, A4, A6, TT, S4, S6, RS6, Allroad Quattro, and Volkswagen Golf, Passat, Touareg applications
• Precision-molded to OE cap dimensions for correct tank compatibility
• Quality cap and seal materials resist engine heat and cooling system exposure
• Factory pressure-tested for cooling system use
• URO part number 1J0121321B

Detailed Description

Use this coolant reservoir cap to restore proper sealing at the expansion tank on vehicles such as the Audi A4, Audi A6 Quattro, and Volkswagen Passat. The cap is engineered to match original dimensions, helping maintain the correct seal on coolant recovery tanks with a handle for cap removal. This URO 1J0121321B replacement is a practical choice when the original cap is cracked, worn, or no longer sealing correctly.

This part cross-references Dorman OE Solutions 603-027 for the same application.

What It Helps Solve

• Coolant loss from a cap that no longer seals properly
• Pressure retention issues in the cooling system
• Cracked, warped, or heat-damaged reservoir cap components
• Warning lights or service concerns related to low coolant level
• Fitment problems when replacing an OE-style coolant tank cap

Installation Notes and Tips

Verify the reservoir neck and cap style before installation. This cap is listed for vehicles with a handle for cap removal, including 2006-2013 Audi A3, 2004-2010 Volkswagen Touareg, 1998-2005 Volkswagen Passat, and 1996-2001 Audi A4. Inspect the tank sealing surface and coolant level before fitting the new cap.

Quality Assurance

URO states this cap is factory pressure-tested and made with materials selected to withstand engine heat and the harsh cooling system environment. It is backed by a 24 Month Unlimited Mileage Warranty.