Dorman 54011 Engine Coolant Reservoir Cap

Engine Coolant Reservoir Cap Replacement

Replace a cracked, missing, or worn coolant reservoir cap with a direct-fit Dorman solution built for the specified Ford and Mercury applications. Dorman 54011 is a black, threaded-on twist cap made from plastic and engineered as a pressurized coolant reservoir cap with a 17.4 PSI maximum pressure rating.

For 1998-2000 Ford Contour, 1998-2000 Mercury Mystique, and 1999-2002 Mercury Cougar automatic transmission vehicles, this cap is listed for the washer fluid reservoir cap application noted in the fitment data. Dorman 54011 provides the correct threaded-on design and sealing profile for the listed vehicles.

Key Features

• Direct replacement engine coolant reservoir cap for the listed applications
• Twist-on, threaded attachment for secure installation
• Pressurized design rated to 17.4 PSI
• Black plastic construction
• 2.2 in diameter and 1.44 in length
• Fits 1999-2002 Mercury Cougar, N/A
• Fits 1998-2000 Ford Contour, N/A
• Fits 1998-2000 Mercury Mystique, N/A

Detailed Description

Dorman 54011 is engineered as a direct replacement cap for the original reservoir cap on the listed Ford and Mercury vehicles. Its threaded-on twist design helps restore proper closure at the reservoir opening, while the pressurized construction supports the system’s specified pressure rating. If you are searching for a coolant reservoir cap for a 1998-2000 Ford Contour, 1998-2000 Mercury Mystique, or 1999-2002 Mercury Cougar, this part number provides a vehicle-specific replacement option. This part cross-references Ford (e.g., F8RZ8100AA) for the same application.

Common Issues This Part Can Address

• Broken or cracked reservoir cap housing
• Missing cap on the coolant reservoir
• Improper sealing at the reservoir opening
• Loss of pressure retention at the cap
• Worn threads that prevent secure twist-on engagement

Installation Notes and Tips

Confirm the reservoir opening matches the threaded-on, twist-style cap design before installation. Inspect the reservoir neck and sealing surface for damage, debris, or coolant residue before fitting the new cap. Verify the application against the vehicle listing for your Ford Contour, Mercury Mystique, or Mercury Cougar, especially on automatic transmission vehicles where the fitment notes apply.

Quality Assurance

Dorman manufactures this replacement cap to match the specified application and pressure rating for the listed vehicles. Part number 54011 is built to replace the original cap form and function for the confirmed fitment shown above.