Elevate your rig with premium Peterbilt 375/377 fuel tank caps and accessories. These durable caps and components offer unbeatable protection and style for your Peterbilt semi-truck. From non-locking to locking fuel caps with pressure relief, find the perfect fit for your make and model. Upgrade your Peterbilt with chrome or plastic covers, gaskets, and anti-siphon kits to keep your fuel secure and your truck looking sharp. Make the most of your Peterbilt 375/377 with high-quality parts that prioritize functionality, convenience, and visual appeal.
Frequently Asked Questions About Peterbilt 375/377 Fuel Tank Caps
Will these fuel tank caps fit my specific year Peterbilt 375 or 377?
Our fuel tank caps are designed to fit Peterbilt 375 and 377 models from 1987 through 2007. These models share the same fuel tank design and cap specifications. However, we recommend checking your existing cap's diameter (typically 4 inches for standard tanks) and thread pattern before ordering. If you have aftermarket fuel tanks, measure the filler neck opening to ensure compatibility.
What's the difference between locking and non-locking fuel caps, and which should I choose?
Non-locking caps provide basic fuel tank protection and are ideal for owner-operators or secure parking situations. Locking caps feature a key mechanism that prevents fuel theft and tampering, making them essential for trucks parked in unsecured areas or company fleets. Most drivers opt for locking caps due to rising fuel costs. All our locking caps come with two keys, and replacement keys can be ordered using the key code stamped on the lock.
Are these fuel caps vented or non-vented, and why does it matter?
Most Peterbilt 375/377 models require vented fuel caps to prevent vacuum buildup in the tank during fuel consumption. Using a non-vented cap on a system designed for venting can cause fuel starvation, engine stumbling, or difficulty removing the cap. Check your original cap for vent holes or markings. When in doubt, choose a vented cap as it's compatible with most applications. Our product descriptions clearly indicate whether each cap is vented or non-vented.
How do I install a new fuel cap, and what should I check for proper fit?
Installation is straightforward: remove your old cap by turning counterclockwise, clean the filler neck threads with a rag, and thread the new cap clockwise until it stops. You should feel resistance and hear 2-3 clicks on ratcheting-style caps. Check that the rubber gasket sits flush against the filler neck with no gaps. If the cap feels loose or doesn't seal properly, verify you have the correct thread size. Most issues stem from cross-threading, so always start threading by hand before tightening.
What materials and finishes are available, and how do they hold up to weather and fuel exposure?
We offer aluminum, chrome-plated steel, and stainless steel options. Aluminum caps are lightweight and corrosion-resistant but may show scratches. Chrome-plated caps provide a mirror finish but can chip or rust if the plating is damaged. Stainless steel offers the best durability and maintains appearance longest, though at a higher price point. All caps feature fuel-resistant rubber gaskets rated for diesel and gasoline. For harsh weather conditions or coastal areas, we recommend stainless steel for maximum longevity.
