Bilstein issues the following tips for correct installation of air suspensions, while issuing a warning about cheap internet parts

Cars supplied with air suspension from the factory are becoming more and more popular. In the meantime, car workshops are also being confronted more and more often with air suspensions.
In one of the latest episodes of the “Suspension Fundamentals – powered by Bilstein Academy” video series, Bilstein says it shows why the challenges for workshops aren’t that great.
Premium suppliers such as Mercedes-Benz, BMW and the like in particular are increasingly equipping their vehicle models with comfortable air suspensions.
Sometimes they have air suspensions fitted both on the rear axle and on the front axle. Others only have air suspension on the rear axle for level control.
For car workshops, this development means new target groups and new potentials. Bilstein explains that it supplies high-quality B3 air springs and B4 air suspension modules for many different vehicles, from the Audi A8 to the VW Touareg.
It says what is particularly interesting is that new additions to the range include spare parts for the Mercedes S-Class W222 and the GLE V167.
First of all, however, Bilstein would like to warn against cheap remanufactured old parts from the internet with regard to air suspension modules.
As we all know, remanufactured starters and alternators can be an alternative to brand-new spare parts.
While the quality of the former is comparable to that of new parts, the situation is different for air suspension modules, says Bilstein.
“We also purchase such cheap products at the Bilstein Academy, of course, and then analyse exactly what’s actually behind them,” Bilstein Academy Head, Rainer Popiol, said.
Bilstein says the alarming thing is that these are often old, discarded air suspension modules that have been spruced up on the outside and made to look “as new”.
Inside, however, old components that have only been repaired as far as necessary and used shock absorbers of varying mileage are at work. In addition, the solenoid valves are often inoperable or missing, turning an active system into a passive one.
There is therefore an immense safety risk for motorists, and there is a great danger for workshops that customers will be left annoyed.
Bilstein takes the view not to do things by halves and it says car workshops can therefore be confident that all Bilstein air suspension components are 100 percent brand new and perfectly match the original equipment in terms of quality.
“We produce air suspension modules for original equipment. And it’s precisely this standard and this quality requirement that we also have for our OE replacement parts,” Rainer said.
Working with products such as the B4 air suspension module or the B3 air spring from Bilstein involves special requirements.
Yet, if mechanics follow a few basics, the replacement of air suspension components can be mastered without any great problems.
There are many components working on the inside of the air suspension module that are already familiar from conventional shock absorbers.
However, the assessment and identification of defects is carried out somewhat differently than in the case of problems with a conventional suspension system.
Since, for example, the B4 air suspension module is designed as an enclosed component, unlike the familiar suspension struts with open shock absorber and separate spring, oil leaks cannot usually be detected.
This makes further checks all the more important. In particular, a test drive to check for noises and driving stability. In addition, automotive professionals can actuate the solenoid valves in order to check the condition of these components.
To replace a defective old air spring or air spring module, workshops should closely follow the installation instructions, in which Bilstein guides automotive professionals through the correct installation step by step using suitable illustrations.
Bilstein expert Mustafa Yavuz has a valuable general tip for the installation of all kinds of air suspension systems: “what I personally always recommend: do not lower the vehicle completely from the car lift, set it down gradually. Before it is lowered completely, pressure must have built up. The engine should also be started, because that way I get the signal via the compressor when there is enough air in the system.”

For more information, visit

Image copyright Bilstein 2022