Frequently Asked Questions About Kenworth T700 Fuel Tank Caps

Will these fuel tank caps fit my specific year Kenworth T700?

Our Kenworth T700 fuel tank caps are designed to fit models from 2011 through current production years. These caps are compatible with both the standard 4-inch and 5-inch tank openings commonly found on T700 models. Before ordering, we recommend measuring your existing tank opening diameter to ensure proper fitment. If you're unsure about compatibility with your specific truck, our customer service team can help verify fitment using your VIN number.

What's the difference between locking and non-locking fuel caps, and which should I choose?

Locking fuel caps feature a key mechanism that prevents unauthorized access to your fuel tank, offering protection against fuel theft and tampering. Non-locking caps provide standard functionality without security features. We recommend locking caps for owner-operators who frequently park in unsecured areas or experience high fuel theft risk. Most locking caps come with two keys, and replacement keys can be ordered using the key code stamped on the lock cylinder.

Are these fuel caps made of aluminum or chrome-plated steel, and how do they hold up against corrosion?

We carry both aluminum and chrome-plated steel options. Aluminum caps are lightweight, naturally corrosion-resistant, and ideal for weight-conscious applications. Chrome-plated steel caps offer a brilliant mirror finish but require more maintenance to prevent rust, especially in winter road salt conditions. Both materials meet DOT specifications for pressure relief and vapor control. For maximum longevity in harsh environments, we recommend aluminum caps with anodized finishes.

Do I need any special tools or modifications to install these fuel caps?

Installation is straightforward and requires no special tools or modifications. Simply remove your old cap by turning counterclockwise and install the new cap by threading it clockwise until it clicks or seats firmly. The caps feature standard threading that matches OEM specifications. Some drivers apply a thin layer of fuel-resistant lubricant to the O-ring before first installation to ensure smooth operation and proper sealing.

How can I tell if my fuel cap needs replacement, and will a faulty cap trigger a check engine light?

Common signs of a failing fuel cap include difficulty tightening, visible cracks in the seal, fuel odor near the tank, or a check engine light with codes P0440, P0442, or P0455. Yes, a faulty fuel cap can trigger your check engine light because it affects the evaporative emission system pressure. A properly functioning cap should create an audible click when tightened and maintain tank pressure. If you notice any fuel seepage around the cap area or persistent fuel smell, replacement is recommended immediately.