Buyer guide
Best air line size for air suspension
The most common air line sizes for air suspension are 1/4" and 3/8". For most builds 1/4" DOT-approved air line is the best choice for smoother suspension travel and easier installation due to the smaller, more flexible line. 3/8" is worth considering if you want more flow and faster air suspension travel.
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What air line actually does
Air line is the tubing that connects every component in your air suspension system together. From the compressor to the tank, from the tank to the manifold / valves, and from the valves out to each air bag. Every time you air up or air down, compressed air is traveling through your lines. It comes in different sizes and materials. Each with their pros, cons, and uses.
Air line sizes explained
There are four main sizes you need to know about for air suspension. Each has a specific role but they all affect the speed at which air moves through your system.
Most common
1/4" air line
The standard for most air suspension builds. Gives you nice, smooth air ups and air downs without being too jerky. Most pressure based managements with presets will be more accurate with hitting heights with 1/4" air line. This is a Bag Riders favorite and what we run in our own cars.
For faster fill times
3/8" air line
Sometimes you just want speed. 3/8" air line gives you that extra quick air up and air down when compared to 1/4". Sometimes 3/8" can move air a little too quickly and will give you a jerking motion when adjusting your heights, however 3/8" is still a very popular option. You can always slow down 3/8" air line with flow controls.
For gauges only
1/8" air line
Used exclusively for running pressure gauges on manual setups. Not for bag or tank lines as the diameter is too small to flow the volume needed for air suspension operation. For gauges on the other hand, you don't really need anything bigger than 1/8" for accurate pressure readings. Plus they're thin and super easy to run behind your dash.
Mini truck style
1/2" air line
Back in the 90s / early 2000s mini trucks were the kings of air suspension. At that time hopping on air suspension was the vibe. Today, especially in the car scene, 1/2" lines are kind of goofy. They're not popular and really only work well with manual air suspension setups with valves and switches. Systems that run preset heights do not function well with 1/2" air lines. We don't recommend 1/2" lines for most applications.
Want to see the actual difference in fill speeds between the popular 1/4" and 3/8" lines? We put them head to head so you see exactly what you'd be in for.
Air line materials - which should you use?
Air line material is mostly about where you're routing the line and how you want the finished build to look. That said, not all materials are created equal - there are right tools for the right job.
Standard choice
DOT-approved nylon line
The go-to air line choice. DOT-rated means it's pressure-tested and certified for use in air brake systems for industrial trucks, so it's more than capable of handling your air ride setup. Flexible enough to route through tight spaces and durable enough to last. This is what comes standard in all of our complete kits and what we recommend for all builds.
Fun choice
Colored air line
Same DOT-rated performance as standard black nylon air line, but available in a range of colors so you can color code your system or match your build's theme. Popular in show cars and custom trunk builds where lines are part of the display.
Show build choice
Aluminum hard line
Hard lines are used to create incredibly clean custom trunk setups. Typically hard lines are only used for what you actually see when popping your trunk and connect to standard nylon air line where the lines disappear into the car. Hard lines don't flex so they're not suitable for anywhere the line needs to move or route around tight bends. Bends need to be made with a proper tube bender.
Avoid
Generic non-DOT tubing
You'll find cheap clear or black tubing at hardware stores that looks like it would work. It won't. Non-GOT tubing isn't rated for the pressures your air suspension runs as and will crack, split, or fail over time. The cost difference between generic tubing and proper DOT line is minimal, so don't cut corners here.
Routing tips
How you route your air lines matters almost as much as what size line you use. Poorly routed lines can rub, kink, or get pinched. All of which will cause problems down the road. Here are things to watch out for.
Tip 01
Protect lines from heat and abrasion
Keep your air lines away from hot objects like your exhaust or sharp components that can chafe the air line. A line that wears through is a slow leak waiting to happen. Also watch out for moving parts that can bind or kink your air line while the car moves up and down.
Tip 02
Avoid sharp bends
Nylon line kinks if bent too sharply, restricting flow or eventually cracking at the bend point. Use gradual curves and secure the line with grommets, clips, or zip ties so it can't move into a tighter bend over time. If you need a sharp turn, consider using an elbow fitting.
Tip 03
Keep connections to a minimum
Less connections means less leak points. It's okay to use union style fittings to connect air lines together, but the more of them you use, the harder it will be to track down leaks. It's always best to try and run complete segments of air line as much as possible.
Tip 04
Keep runs as short as possible
Every extra foot of line between your tank and bags is a tiny bit more volume the system has to fill. Shorter runs mean faster response. Plan your layout before you start routing so you're not adding unnecessary length.
Not sure what line and fittings you need for your specific setup? Hit us up at [email protected], call us at 844-404-7344, or use the chat button on the site. We've been building air suspension setups since 2009 and we're happy to walk you through exactly what you need.