Shop Freightliner Cascadia 113 & 125 Fuel Tank Caps

When it comes to fuel tank caps for your Freightliner Cascadia 113/125, 4 State Trucks has you covered. From locking and non-locking options to tethered and Cam-On fuel caps, there's something for everyone. Whether you prefer OEM or aftermarket parts, we've got the perfect fit for your needs.

Freightliner Cascadia 113/125 Fuel Tank Caps

The Freightliner Cascadia 113/125 Fuel Tank Caps product lineup includes a wide range of fuel tank caps and related accessories for the popular Freightliner Cascadia semi-truck models. Whether you need a non-vented locking cap, a vented cap with an anti-siphon tube, or a replacement gasket, this product lineup has you covered. The caps are designed to provide a secure and reliable seal to prevent fuel leaks and theft, while also accommodating ventilation needs. Many feature push-and-twist or 1/4-turn mechanisms for easy and convenient access. Customers can also find chrome and plastic cap covers to add a stylish touch to their Cascadia's fuel system. With a focus on quality, compatibility, and functionality, this product lineup ensures Cascadia owners can keep their fuel tanks properly sealed and protected.

Frequently Asked Questions About Freightliner Cascadia 113/125 Fuel Tank Caps

Q: Will these fuel tank caps fit my specific year Cascadia?

Our fuel tank caps are designed to fit Freightliner Cascadia 113 and 125 models from 2008 to present. However, there were minor changes in 2018 with the New Cascadia release. Most caps are universal between these years, but we recommend checking your current cap's thread size (typically 2.5" or 3.5") and comparing it to the product specifications. If you're unsure, contact us with your VIN and we'll help verify compatibility.

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

Locking fuel caps feature a built-in key mechanism that prevents unauthorized access to your fuel tank, which is essential for owner-operators and fleets concerned about fuel theft. Non-locking caps use a standard twist-on design for quick access. Both types seal equally well when properly installed. Locking caps typically add $15-30 to the cost but can save hundreds in prevented fuel theft.

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

Most modern Cascadia models require vented fuel caps to prevent vacuum buildup in the tank. Vented caps have a small pressure relief valve built into the cap. Using a non-vented cap on a system designed for venting can cause fuel pump issues and poor engine performance. Check your original cap - if it has a small spring-loaded valve visible on the underside, you need a vented replacement.

Q: How do I prevent fuel cap leaks and ensure a proper seal?

First, inspect and clean the fuel tank neck threads before installing a new cap. Replace the rubber O-ring or gasket if it shows any cracks or compression. When installing, turn the cap clockwise until you feel resistance, then tighten an additional 1/4 turn - over-tightening can damage the seal. If you're experiencing persistent leaks, the issue may be with the tank neck itself rather than the cap.

Q: What materials are best for durability and longevity?

Aluminum caps offer the best corrosion resistance and typically last 5-7 years in normal conditions. Chrome-plated steel caps provide a premium appearance but may show rust after 2-3 years in harsh climates. Heavy-duty polymer caps are impact-resistant and won't corrode but may fade in extreme sun exposure. For maximum durability in all conditions, we recommend aluminum caps with reinforced polymer gaskets.