Air Suspension

Dunlop Air Suspension
Motorhome Air SuspensionImprove stability, safety and comfort

Air suspension can improve the stability, safety and comfort levels of your journey by correcting ride height and improving weight distribution. If you frequently drive on uneven roads or carry heavy or variable loads, an auxiliary air suspension kit could transform your journeys.

Dunlop Air Assist produce air suspension systems for Light Commercial Vehicles between 1.5t and 7.5t.  For larger vehicles we can also provide a solution.

What is air suspension?

Air suspension systems are aftermarket accessories which can be fitted to light commercial vehicles chassis to improve safety, stability and comfort. So whether you drive a Motorhome or a Van we can get the kit for you.

Auxiliary air suspension (SemiAir) works with the existing leaf springs and is installed between the rear axle and chassis, giving the opportunity to raise and lower the vehicle within the limits of the leaf spring suspension.

Depending on the type of auxiliary air suspension kit this can be done manually or automatically.

  • Unstable handling
  • Higher sensitivity to cross-winds
  • Less grip on the front wheels
  • Long, or too long a braking distance
  • Can dangerously blind oncoming drivers
  • Increased risk of damage


    • More driving comfort and better roadholding
    • Always sufficient ground clearance
    • Highly stable left/right divided system
    • Allows vehicle to be raised safely to drive on and off ferries
    • Levels on an uneven surface
    • More grip on the front wheels
    • Better steering
    • Shorter braking distance
Why buy a SemiAir air suspension kit?

SemiAir is well suited to both commercial applications such as goods transport or trade use, and to leisure applications as an entry point for air suspension for motorhomes.

SemiAir is ideal if you are frequently towing or hauling heavy or often variable loads, or if you require greater ground clearance for the rear of your vehicle, or more stability while driving under load.

It is a relatively inexpensive solution which is fast to install and helps to protect your vehicle and load from damage.

The functionality allows the height of your vehicle (within the limits of the leaf spring suspension) to be adjusted by increasing/decreasing the air pressure in the air springs. This keeps your vehicle at a steady height above the road surface and reduces the appearance of heavy loads.


This can be increased significantly with auxiliary air suspension because the pressure in the air spring helps to restore the intended ride height and keep your vehicle level throughout the journey. It also restores the original intended spring travel, and allows the leaf spring and shock absorbers to move and function as intended.

Removing the original suspension and replacing it with air springs means that the vehicle is fully cushioned by the air springs, reducing high frequency vibrations and unwanted noise.

This makes the vehicle quieter, smoother and more pleasant to travel in, and for the transportation of fragile items helps to protect the load from damage in transit (e.g. computer equipment, fine art/antiques etc.)


The improved weight distribution and level ride height helps to ensure that dynamic inputs such as steering, braking and acceleration all operate as intended. The dual chamber aspect of the system helps to also stabilise off-centre loads.


You will be able to adjust the height of your vehicle by adding or removing pressure from the airbags as appropriate. This gives you a variable force spring which can be adjusted to meet the requirements of your load*, and raise the rear of the vehicle, e.g. to hitch to a tow bar.


It’s that time again! You’re itching to go camping so you collect your motorhome from storage and you can already see yourself relaxing beside a babbling stream. You plan your route to a beautiful destination and, with a fully packed motorhome, set off on your holiday.

Your unstable handling soon becomes obvious due to swaying in gusts of wind, less grip on the front wheels, too long a braking distance and bouncing when you go over a ramp.

Unfortunately the design of motorhomes is such that the manufacturer puts a lot of weight behind the rear axle and the longer the distance from the rear wheels the greater the effect that has on the stability of the vehicle. With some motorhomes having nearly 2 metres behind the rear wheels with garages that can take 800kg you can see that simple physics means this will put a lot of pressure on the standard van rear springs. We have seen some motorhomes come in with the springs being flat and that is brand new not and old vehicle with mileage on it.

The right Dunlop air assist system will stabilise the motorhome significantly. Air suspension is unknown to many and consequently unloved. Over the years, however, Dunlop Air Assist has become something of an icon among air suspension systems and now well known in practically every part of the world. Anyone who has ever driven a vehicle with it, will never want to do without. The motorhome will be much more comfortable to drive, the ride height more consistent, you’ll be less affected by ramps and gusts of wind and be generally safer on the road.

View the latest driving comfort solution for your motorhome here!


The interior storage for your commercial vehicle has been perfectly customised, keeping it as light, steady and user-friendly as possible. Now that you have loaded all your tools and materials, it is heavier than you anticipated.

What do I need to consider?

 The best kit for you will depend on how you use your vehicle and what you wish to achieve from it, and what you would wish to spend.

With a SemiAir kit you can quickly and relatively cheaply add auxiliary air bags to your rear suspension. This fits between the rear axle and chassis of your vehicle.

Motorhome air suspension: Motorhomes operate at a maximum weight capacity almost all of the time, so the regular suspension can’t work as efficiently as you might like it to. You can replace the bump stops or auxiliary springs with an air suspension spring to take away some of the banging and increase stability when you are driving.


We always recommend having any modifications to your vehicle being completed by a professional.  It is possible to fit a SemiAir suspension kit yourself, but you should only do this if you have the correct equipment and the mechanical expertise.

*Within the limitations of the maximum GVW/Axle Weight of the vehicle). In some cases an air suspension kit can be used to increase the Gross Vehicle Weight (GVW) of a commercial vehicle.

We do a comprehensive range of products for your motorhome, for more information click here.

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