Calorstat RC0028 Engine Coolant Reservoir Cap

Engine Coolant Reservoir Cap for Audi, Porsche, Volkswagen

Calorstat RC0028 is a standard threaded engine coolant reservoir cap built from plastic and rubber for pressurized cooling systems. With a 22.0 psi pressure rating, it helps maintain the correct system pressure for a wide range of Audi, Porsche, and Volkswagen applications, including Audi A4, A6, TT, Q7, and Porsche Cayenne and Panamera models.

Key Features

• Engine coolant reservoir cap with threaded attachment type
• Plastic and rubber construction for cooling system sealing
• Pressurized design with a 22.0 psi maximum pressure rating
• Standard type cap with no pressure release lever
• Direct-fit style replacement for select Audi, Porsche, and Volkswagen vehicles

Detailed Description

Calorstat RC0028 is an OE-style coolant reservoir cap for pressurized expansion tanks and coolant reservoirs. It is specified for applications such as Fits 2010-2016 Porsche Panamera, N/A; Fits 2007-2015 Audi Q7, N/A; Fits 2004-2010 Volkswagen Touareg, N/A; and Fits 1996-2002 Audi A4, N/A. This part cross-references Gates 31529 for the same application. The RC0028 part number is also used across multiple European vehicle cooling system applications where a threaded, pressure-rated cap is required.

What It Helps Address

• Coolant loss from a cap that no longer seals properly
• Pressure-related cooling system faults caused by a weak or damaged cap
• Overflow or venting issues from an incorrect reservoir cap rating
• Hard-to-diagnose temperature fluctuations linked to cooling system pressure loss
• Replacement needs for worn plastic or rubber sealing components

Installation Notes and Tips

Verify the reservoir neck style, thread engagement, and pressure rating before installation. Match the cap to the vehicle application and cooling system specification, especially on Audi, Porsche, and Volkswagen models where OE-style pressure control is important. Inspect the reservoir sealing surface and surrounding cooling system components for wear, cracks, or contamination before fitting the new cap.

Quality Assurance

Calorstat is listed as an OE supplier for several Audi and Volkswagen applications, and this cap follows the pressure and fitment requirements shown for the confirmed vehicle listings. Use the part number RC0028 and the vehicle-specific fitment data to confirm application before purchase.