Keep your rig running smooth and safe with high-quality semi truck air lines, hoses, and fittings. Whether you're hauling heavy loads or just trying to stay DOT-compliant, these parts are must-haves for your air and brake systems.

What Do Air Line Fittings Do?

Air lines carry compressed air from your tractor to your trailer. They control your air brakes, suspension, and other key systems. Without them, your truck can’t stop properly—or even move. That’s why having the right air hose for semi trucks is critical. It’s not just about performance. It’s about safety.

Why Upgrade Your Air Line Setup?

- Stay DOT-compliant with durable, leak-free hoses and fittings. - Prevent downtime with aftermarket parts that last through extreme temps and road abuse. - Improve flexibility with coiled trailer air lines that reduce kinks and wear. - Simplify repairs with pre-assembled hose kits, backplates, and bulkhead accessories. - Maximize compatibility with universal fittings, rubber air intake hose adapters, and trailer gladhand sets. Shop Popular Replacement Parts: - Rubber and coiled tractor trailer air lines: built to handle pressure and movement - Semi truck air line fittings: brass, steel, and composite options available - Air line box backplates: great for organizing multiple trailer lines - Extended-grip gladhands: for quick hookups and solid seals - Hydraulic hoses: for lift gates, trailers, and heavy equipment applications. These heavy-duty components are built for daily wear and tea, and pair nicely with aftermarket air dryer kits to keep the moisture out of your air lines, and href=”/semi-truck-frame-chassis/”>automatic slack adjusters or camshaft components to beef up your truck’s stopping power. Whether you're replacing a single worn-out fitting or upgrading your full air system, we’ve got the right parts to get the job done.

Find the Perfect Replacement Air Fittings at 4 State Trucks

No matter your truck make or model, you’ll find trusted aftermarket options here. Keep your air brake system tight and your trailer air lines flowing freely with reliable parts that won’t let you down. Shop now and get your semi truck the air system it deserves.