Dorman 54231 Engine Coolant Reservoir Cap

Dorman 54231 Engine Coolant Reservoir Cap

Replace a cracked, missing, or worn coolant reservoir cap with a direct-fit Dorman 54231 engine coolant reservoir cap. This black plastic twist cap is vented and built for a screw-on attachment, making it a practical replacement for select Lexus applications.

Key Features

• Direct replacement engine coolant reservoir cap for select vehicles
• Black plastic construction with a 66 mm diameter
• Twist-on, screw-on attachment for straightforward service
• Vented design; not pressurized
• Fits 1998-2005 Lexus GS300 and 1998-2000 Lexus GS400 applications noted below

Product Details

Dorman 54231 is engineered to replace the original coolant reservoir cap with the correct fit and function for the application. The cap uses a twist, screw-on design and measures 2.60 in. by 2.60 in., with a 66 mm diameter and black plastic construction. It is vented and does not use a pressure release lever, which matches the listed reservoir-cap configuration for the covered Lexus vehicles. This part number, 54231, is a focused replacement choice for owners searching for a Lexus GS300 coolant reservoir cap or Lexus GS400 reservoir cap by part number.

This part cross-references 1640546080 for the same application.

Fitment

• Fits 1998-2005 Lexus GS300, N/A. Notes: Fits washer fluid reservoir cap on automatic transmission vehicles.
• Fits 1998-2000 Lexus GS400, N/A. Notes: Fits washer fluid reservoir cap on automatic transmission vehicles.

Common Issues This Part Can Address

• Cracked reservoir cap causing a poor seal at the tank opening
• Lost coolant reservoir cap leaving the reservoir exposed
• Damaged twist threads that prevent proper cap retention
• Worn vented cap that no longer matches the original design
• Incorrect replacement cap size or style on select Lexus GS models

Installation Notes and Tips

Confirm the reservoir opening diameter and cap style before installation. Match the 66 mm size, vented design, and screw-on twist attachment to the original cap. For the listed Lexus GS300 and GS400 applications, verify the vehicle configuration notes before ordering and install the cap by hand until fully seated.

Quality Assurance

Dorman manufactures direct replacement parts to match original equipment fit and function. Part number 54231 is built to provide the specified cap style and dimensions for the listed applications.