POLYAIR, RIVAL, FOX Air Suspension with Fitting Position Front Axle

Air suspension, also known as airbag suspension or air ride suspension, uses an air spring in place of or alongside a conventional coil or leaf spring. Adding air raises the vehicle and increases its load capacity, and releasing it lowers the vehicle back down.

For most Australian drivers the interest is practical rather than technical. A vehicle that sags under load, drags its rear end when towing, or sits nose-high with a full tray is a vehicle that airbag suspension can fix.

What Airbag Suspension Does for a Loaded Vehicle

A spring is chosen by the manufacturer around an average load, which means it is a compromise the moment you put weight in the vehicle.

Load the tray, hitch a van or fit a canopy and drawers, and the rear settles. That single change sets off several others at once. Headlights point upward into oncoming traffic, weight transfers off the front wheels so steering feels light and vague, and the rear suspension sits closer to its bump stops with less travel left to absorb anything.

Air bags restore the ride height the vehicle was designed to sit at. Pressure goes in until the rear is level again, the headlights point where they should, the front regains its weight and its steering feel, and the suspension gets its travel back.

What they also do is let you change the support without changing the springs. Empty during the week, loaded at the weekend, and the same vehicle handles both because you adjust the pressure rather than living with one fixed rate.

Helper Airbags or Full Air Suspension

Two different products share the name and it is worth being clear which suits your situation.

Helper airbags work alongside the springs already on the vehicle. The coil or leaf stays in place carrying the vehicle, and the bag adds support on top when it is needed. Pressure is adjusted to suit the load, and with minimal pressure the vehicle drives much as it did before. This is what most 4x4, ute and light commercial owners are actually after, and it is the more common installation by a wide margin.

Full air suspension replaces the spring entirely, with the bag carrying all the load and ride height controlled by pressure. It appears on some passenger vehicles from the factory and on purpose built setups, and it offers more adjustment at the cost of more complexity.

Which one suits you depends on the vehicle and what it does. That is worth a conversation before ordering rather than after, and it is the sort of thing our Service Centres deal with daily.

Rear Suspension Air Bags on Utes and 4WDs

The rear is where almost every Australian installation happens, and the reasons are specific to how these vehicles are used.

A dual cab ute carries its load behind the rear axle, which is the worst place for it in terms of leverage. Add a canopy, a drawer system, a second battery, a long range tank and a fridge, and a vehicle that was rated for a tonne in the tray is already carrying a permanent load before anything goes in.

Leaf sprung utes also sit on springs chosen for a commercial duty cycle rather than for touring. They are firm when empty and sag under sustained weight, which is the opposite of what a touring setup wants.

Rear suspension air bags address both by adding support that is only there when you need it. Run minimal pressure for the drive to work and increase it for the trip away, without the permanently harsh ride that comes from fitting heavier springs to solve an occasional problem.

On a coil sprung 4WD the principle is the same, though the mounting arrangement differs and the bag usually sits inside or alongside the coil rather than on a leaf pack.

Air Bag Suspension for Towing and Caravans

Towing is where airbag suspension earns its keep for most people.

A van or trailer puts ball weight on the towbar, which sits behind the rear axle and acts as a lever. The rear of the tow vehicle drops, the front lifts, and the vehicle becomes less stable exactly when stability matters most. Vehicle sway becomes easier to provoke and harder to settle.

Air bag suspension for towing caravans works by restoring level. Adding pressure brings the rear back up, which puts weight back on the front wheels where the steering and most of the braking happens. The vehicle tracks straighter, it responds more predictably to steering input, and the suspension has travel available for road irregularities rather than sitting compressed.

It is worth being clear about what it does not do. Air bags level the vehicle and restore capacity within the manufacturer's limits. They do not raise your GVM or towing capacity, and they are not a substitute for correct weight distribution in the van or a properly set up towing system.

What Is in an Air Bag Suspension Kit

Contents vary by vehicle and by the type of system, though most share the same components.

An air suspension kit is built around the air springs themselves, with brackets to mount them to the axle and chassis, air lines, fittings and inflation valves making up the rest. Simpler setups use a single valve and a tyre inflator, which suits a vehicle that is loaded and unloaded occasionally.

More complete systems add an onboard compressor, a control panel and separate management for each side, which allows adjustment from the cabin and lets you correct an unevenly loaded vehicle by running different pressures left and right.

Air suspension parts are also available individually, since air springs, lines and fittings are serviceable items on a system that has been in place for years.

Airbag Suspension Price and What Affects It

Airbag suspension price varies more than most suspension work, because the systems themselves vary so much.

A basic helper airbag kit with manual inflation sits at one end. An onboard compressor, dual control and cabin mounted management sits considerably higher. Between those two there is a wide range, and the right answer depends on how often you load and unload rather than on the biggest number you can justify.

Installation is the other variable in any quote, since some vehicles have straightforward mounting points and clear runs for the air lines, while others need more time to route lines safely and mount the compressor where it stays dry and accessible.

Talking through what the vehicle actually does, before choosing a system, usually saves money rather than costing it. A vehicle that tows every weekend and one that carries a load twice a year need different answers.

Air Bag Suspension Installation

Installation quality determines whether a system lasts, and it is where most of the problems we see originate.

Air lines need routing away from heat, away from moving suspension components and away from anywhere they can chafe. Brackets need mounting square so the bag inflates and deflates without rubbing. The bag needs clearance through the full range of suspension travel, checked at both extremes rather than at ride height. Fittings need to seal properly, since a slow leak in an air system is difficult to trace after the fact.

None of that is complicated work, and all of it is easy to get subtly wrong.

Fulcrum has been fitting suspension since 1976, with 16 Service Centres across Australia and 200+ authorised workshops. If you would rather have the system fitted, checked and set up correctly the first time, that is what the network is there for.

Choosing the Right Air Suspension Setup for Your Vehicle

The questions worth answering before choosing anything are straightforward.

What does the vehicle carry, and how often? A permanent canopy and drawers is a different problem to an occasional trailer.

What is the ball weight when you tow? That figure decides how much support the rear actually needs.

Is the vehicle loaded evenly from side to side? A drawer system on one side or a long range tank offset to one side means independent control is worth having.

And how is the rest of the suspension holding up? If the springs are tired or the shocks are worn, air bags will mask the symptom rather than fix the cause, and the vehicle will drive better for having the underlying problem sorted first.

We would rather talk that through and recommend the right system than sell the wrong one.

Find Air Suspension for Your Vehicle

For extra support built into the damper, air shocks combine a shock absorber with an adjustable air chamber. Compressors, controllers and gauges for a full onboard system sit in our air suspension electronic components range. For springs, shocks and the rest of the setup, see our full suspension parts range.

Select your vehicle to see the airbag suspension kits and air suspension parts available for it, or talk to your nearest Service Centre about what suits the way your vehicle is loaded. Every product we supply is backed by our warranty, a fitment guarantee and the support of a nationwide workshop network.