Frequently Asked Questions About Ford Aeromax Truck Fuel Tank Caps

Will these fuel tank caps fit my specific Ford Aeromax model year?

Our fuel tank caps are designed to fit Ford Aeromax trucks from 1988 to 1998. However, there are two main thread sizes: 2-inch and 2.5-inch diameter. Most 1988-1993 models use the 2-inch caps, while 1994-1998 models typically use the 2.5-inch caps. We recommend checking your existing cap or tank opening before ordering. If you're unsure, contact us with your VIN and we'll help identify the correct size.

Are these caps vented or non-vented, and which type do I need?

Most Ford Aeromax trucks require vented fuel caps to prevent vacuum buildup in the tank. Vented caps have a small pressure relief valve that allows air to enter as fuel is consumed. Using a non-vented cap on a system designed for vented caps can cause fuel pump issues and poor engine performance. All our Aeromax replacement caps come pre-vented unless specifically noted as non-vented for specialized applications.

What's the difference between locking and non-locking fuel caps?

Locking fuel caps require a key to remove and provide security against fuel theft and tampering. They typically come with two keys and use a spring-loaded mechanism. Non-locking caps use a standard twist-on design. Both types seal equally well when properly installed. Locking caps add about $15-25 to the cost but are recommended if you park in unsecured areas or have experienced fuel theft.

How do I know if my fuel cap is failing and needs replacement?

Common signs include: a strong fuel smell around the tank area, the check engine light coming on (often with code P0440 or P0457), difficulty removing the cap due to vacuum pressure, visible cracks in the rubber gasket, or the cap not clicking when tightened. A failing cap can cause fuel evaporation, reduced fuel economy, and emissions test failures. If your cap is over 5 years old or shows any of these symptoms, replacement is recommended.

Are aftermarket caps as good as OEM Ford caps?

Quality aftermarket caps from reputable manufacturers like Gates, Stant, and Motorad meet or exceed OEM specifications. They use the same materials (high-impact polymer with nitrile rubber seals) and are tested to the same pressure and durability standards. The main difference is price - aftermarket caps typically cost 40-60% less than Ford OEM caps. We only stock caps that meet SAE J1114 standards and carry manufacturer warranties.