Frequently Asked Questions About International LT Fuel Tank Caps

Will these fuel tank caps fit my specific International LT model year?

Our fuel tank caps are designed to fit International LT models from 2017 to present. However, there are variations between standard and extended range fuel tanks. Standard 100-gallon tanks use a 3.5-inch cap opening, while the 150-gallon extended range tanks require a 4-inch cap. Always verify your tank size and cap diameter before ordering. If you're unsure, check your existing cap's backside for size markings or contact our support team with your VIN for exact fitment confirmation.

Are locking fuel caps worth it, and how durable are the lock mechanisms?

Locking fuel caps are highly recommended for drivers who park in unsecured lots or high-theft areas. Our locking caps feature hardened steel mechanisms that resist picking and forced entry. The locks are tested for 10,000+ cycles and include weather seals to prevent corrosion. Each locking cap comes with two keys, and replacement keys can be ordered using the code stamped on your original keys. Non-locking caps are suitable for secure parking situations and offer easier daily access.

What's the difference between aluminum and chrome-plated fuel caps?

Aluminum caps are lightweight, naturally corrosion-resistant, and maintain their appearance with minimal maintenance. They're ideal for drivers in harsh weather conditions. Chrome-plated caps offer a mirror-like finish that matches other chrome accessories but require regular polishing to prevent pitting and maintain shine. Chrome caps typically cost 20-30% more than aluminum. Both options use the same high-quality rubber gaskets and threading, so performance and seal quality are identical.

How do I prevent fuel cap leaks and ensure proper installation?

Proper installation requires cleaning the tank neck threads before installing your new cap. Apply a thin layer of diesel-safe lubricant to the cap's O-ring gasket. Thread the cap clockwise until you feel resistance, then turn an additional 1/4 turn only. Over-tightening can damage the gasket and cause leaks. Replace the O-ring annually or if you notice any cracks or flattening. Keep a spare O-ring in your truck as they cost under $5 and can prevent costly fuel loss.

Can I install a vented fuel cap on my International LT, and when is it necessary?

Most 2017+ International LT models have EVAP systems that require non-vented caps. Installing a vented cap on these trucks will trigger check engine lights and emissions faults. Vented caps are only appropriate for pre-2017 models or trucks with modified fuel systems. If you're experiencing tank vacuum issues, the problem is likely a clogged tank vent line, not the cap itself. Always use the cap type specified in your owner's manual to maintain proper fuel system operation and emissions compliance.