This week we met a very nice chap with a very nasty problem.
His old air suspension was not working, the vehicle had failed its MOT, the van was urgently needed, and the chassis was cracked and broken from top to bottom on both sides, and between them in a giant U shape.
That is not a normal air suspension repair. It is not often that we have to weld up damaged chassis sections, but it does happen. In this case, the damage was not caused by rust. It appeared to have been caused by a heavy van fitted with a poorly designed air suspension kit that did not spread the loads correctly.
When Air Suspension Loads Are Not Spread Properly
Air suspension can put very significant loads into a vehicle chassis. That is not a problem when the kit is designed properly, the correct air bags are used, and the brackets spread the load into the chassis as intended.
The problem starts when a kit concentrates those loads into too small an area.
This particular kit was from a manufacturer whose products we have removed and replaced many, many times before. The kits are not designed with servicing and maintenance in mind, so we often end up having to cut them off the vehicle. This one was the same. Seriously rusty, seriously seized, seriously broken, not working, and it had seriously damaged the van. All held on by an exhaust clamp!
There are now plenty of kits finding their way onto popular sales channels that do not spread the loads correctly. At best, that can lead to MOT failure and an expensive repair. At worst, cracked and broken chassis sections can become a serious safety issue.
The Wrong Kit for the Vehicle
In this case, the vehicle was a heavy van with limited space available. It had been fitted with a kit that was too tall, using air bags that were also too large for the available space.
We suspect the customer had been upsold to larger air bags. That is something we see far too often. Bigger is not automatically better. In fact, fitting a larger air bag where there is not enough space can make the system worse, not better.
This is why AirRide will usually ask for the distance between the chassis and the axle before supplying certain kits. We are not asking to make life difficult. We are asking because the dimensions matter. The wrong bag, in the wrong space, on the wrong bracket, can damage the vehicle. This is more common on some models of Mercedes, but can happen on almost any van or motorhome.
Any seller supplying this type of kit without asking basic fitment questions probably does not care enough about what the kit does to your chassis.
Bigger Bags Are Not Always an Upgrade
There is generally one correct style and size of air bag for a particular vehicle and installation.
Paying extra for a different choice of bag only gets you a better kit if the original kit was deliberately under-specified in the first place. We have never really understood the logic behind that type of upsell.
At AirRide, we use the correct bag in the first place. The aim is not to sell the biggest bag. The aim is to use the right bag, in the right position, with brackets that spread the loads correctly.
Poor Kit Design Can Be Expensive
The seller involved in the kit we removed has been known in the industry for over a decade. In earlier days, they appeared to trade using a Gmail address and a mobile phone number, with no clear company name on paperwork. That sort of setup should make any buyer cautious.
Things may have moved on in terms of telephone numbers, websites and email addresses, but poor quality kits are still out there.
Worse still, in the last 12 months we have seen the development of foreign-made kits with even higher concentrated loads. Some of these designs appear to have been made primarily to reduce manufacturing cost. A single pressed bracket can be made very cheaply in one operation, which is great for cutting production costs. It is not so great if the entire suspension load is then concentrated into a tiny area of the chassis.
In some cases, the load-bearing area can be a fraction of what should be used for the job. In our view and experience, that makes chassis damage almost inevitable in the medium to long term, especially on heavily loaded vehicles.
Heavy Vans Need Proper Load Spreading
The loads generated by air suspension systems can be very significant. That is especially true if the kit is being asked to actively and constantly lift the vehicle, as it was in this case.
Some applications need large spreader plates in addition to the main kit. Not every vehicle needs them, but where they are needed, they really matter. The bracket design, air bag choice, available space and actual vehicle weight all need to be considered together.
Several factors help ensure that an air suspension kit does not damage the vehicle:
- The kit must be properly designed.
- The air bags must be correctly chosen.
- The brackets must spread the load correctly.
- The system must be matched to the actual vehicle dimensions.
- The installation must take into account how the vehicle is used.
Compromise in any of those areas can be costly for the buyer.
Repairing the Damage
This vehicle had already been welded in the past because of the kit overload. It then cracked again just past the welds. That tells its own story.
We removed the offending kit, repaired the chassis, and fitted the correct air suspension kit. The repair was time consuming, as chassis welding often requires internal items to be removed or protected before welding can safely take place. All underseal and seam sealer must be removed, and rust cleaned back to bright metal. We then use thick metal to plate over after welding the crack itself - not just covering it.
Happily, the customer left with the vehicle repaired and the correct kit fitted. We later noticed online that the van passed its MOT the next day.
That is always a good result, but it should not have needed to happen in the first place.
Buying Right Means Buying Once
Air suspension is not just about fitting an air bag between two points and hoping for the best.
A properly designed kit supports the vehicle, improves ride and stability, and works with the chassis rather than damaging it. A poorly designed kit can cause exactly the opposite. The lesson is simple. Buy the right kit the first time.
If a seller does not ask the right questions, does not understand chassis loading, does not design for servicing, and does not spread the loads properly, the cheap option can become very much the expensive option.
If it does not come from AirRide Limited or Airide Limited, then it is not AirRide. It is just air suspension.
Get in Touch
Need more information? Our team is here to help!
- Call us: 0800 772 0315
- Email us: ENQUIRIES@AIRRIDE.UK