AirTec offers high-quality repair of all types of air springs. Only at AirTec do you receive a comprehensive service covering everything connected with your air suspension! AirTec is the only company in Bulgaria offering repair using original ОЕМ rubber!
What do we do prior to repairing your air suspension?
- Preliminary motor vehicle diagnostics
aimed at establishing how the air suspension system works. There are cases in which the car seems to have ‘squatted’, and its owner immediately thinks that there is a broken air spring. More often than not, however, the air springs are in good condition, and there is a problem with some other parts, such as level sensors, the compressor, the compressor relay, the valve block, etc. The accurate diagnostics will save you time and money, on the one hand, and unnecessary repairs, on the other. - Assembly / Disassembly of the damaged/broken air spring. You do not need to deal with other companies or bring your shock absorber in person to be repaired. It is all part of the service we provide – thus saving you precious time.
Repair-recycling process
The process of repairing the air spring consists of several stages:
1.Cleaning and disassembling
After disassembly, the “air shock absorber” is disassembled into component parts. An air strut (in jargon) consists of an airspring and an electrically adjustable shock absorber.
2.Inspection, measurements and localization of the defect. After everything is disassembled, the defect is identified. Most often, the rubber sleeve is damaged (has burst). The damage can be due to various reasons such as:
- rubbing of the rubber due to wear and tear or from stones and dust particles;
- shock absorber leakage, in which leaked hydraulic oil corrodes the rubber and the sleeve bursts;
- total failure of the shock absorber to absorb road irregularities – leads to excessive peak loads on the sleeve/the air spring.
3. 
Testing on the computerized test bench – Shock absorber Dyno. A damaged shock absorber is the most common cause for the air spring to burst.
Every shock absorber that has passed through our company is tested on a test bench, regardless of whether there are complaints about it! With this test, we always ensure and prevent future damage to the new air spring. Air spring repair makes sense only if the shock absorber is in good condition, otherwise it will fail again very soon. AirTec offers shock-absorber repair of impeccable quality (for further information, refer to the section ‘Adaptive shock absorbers’). This test is a key element of our quality control system and an undeniable advantage over our competitors. Using the test bench, we are able to check the behavior of the shock absorber under load and speed conditions identical to those on the road. So finally we present you with reliable FACTS in graphic form, not just “diagnostics based on hearing and smell”.
The quality of a service is in the detail. 😉
4.Replacement of parts.
At this stage, a number of parts are replaced, such as rings, rubber sleeve, mounts, valves, dust covers, bearing metal parts and others. One of our unique advantages is that we use a new rubber sleeve the wall, braid and thickness of which are identical to the original. The advantages of OEM (intended for original installation) rubber over other types of aftermarket rubber sleeves are really significant:
- The thickness of the new rubber is 2mm (as the original). Aftermarket rubber is 3-3.5mm thick. Because of its increased thickness, the aftermarket cracks faster and more easily. The thickness is NOT important for the strength of the sleeve, because all the load is taken by the cords, not by the thickness of the rubber layer. With us you get original quality!
- • The braid is special, that is, less fabric, but stronger fiber. In this way, the load capacity of the air spring is increased with the same flexibility and increased comfort.
- • The rubber sleeve is made of extremely soft, flexible and elastic rubber. The more elastic the rubber, the harder it is to crack. Thus, the behavior of our recycled air springs is impeccable and long-lasting, even in the harshest atmospheric conditions. It is known that most air springs recycled in Bulgaria break down precisely in the winter in the cold, because in the cold the rubber becomes even harder. With us, these risks are eliminated, thanks to the quality sleeves we work with!100% Made in Europe & Assembled by AirTec !
All necessary mounts, seals and dust covers are replaced with new original parts. Thus practically everything on the air spring becomes new. 
5. Crimping
A key point in the repair is pressing the rubber to the top and bottom of the air spring. What exactly does it involve? The rubber sleeve must be hermetically connected to the hard parts of the air spring (usually these are aluminum “heads”), that is, we must squeeze the rubber to the other parts without letting air out anywhere. The air pressure in the rubber sleeve during operation is about 5-10 bar and even higher (peak pressures). This requires an extremely strong and reliable adhesion between the rubber and the metal parts. This connection/adhesion is achieved through steel rings that clip the rubber to the metal parts. The steel ring is pressed on a special press, tightly pressing the rubber. Although this process seems quite simple, it is the most critical point in air spring repair! Improper pressing (crimping) is the most common cause of future problems and low quality of the service performed.
Possible errors during crimping:
- Insufficient crimping – the steel crimping ring is not sufficiently compressed, in which case it does not press the rubber hard enough, as a result, the rubber slips out from under the ring at the first higher load (for example, the car goes over a bump at a higher speed).
- Tearing of the rubber during crimping – The wall of the rubber sleeve, which bears the entire weight of the car, consists of rubber and several layers of special fabric-like cords. It is the layers of fabric that are the supporting element. When pressing, it is necessary to apply enormous force (in some cases over 100 tons!) along the entire perimeter of the ring with extreme precision and not to exceed the specified pressing diameter. If we apply too much force or squeeze the ring to too small a diameter, the layers of cord in the rubber are torn. A ring literally cuts the threads and the whole sleeve is left to hold only the remaining layer of rubber. We get a seemingly solid sleeve that will explode over the first hole. In order to avoid tearing the rubber, it is necessary to press it precisely, without exceeding a certain force, while at the same time the final pressing diameter is accurate to hundredths.
- Damage to the metal parts to which rubber is crimped – To keep the weight of the car as low as possible, manufacturers use sufficiently strong, thin-walled metal (and in some cases plastic) parts. Since the crimping press is hydraulic with a capacity of over 280 tons, it is easy for it to literally crush the metal parts that we are crimping the steel ring to. In other cases, if the sleeve has already been made poorly once, it is possible that the metal part is deformed elliptically, has yielded a little (invisible to the eye, but enough to cause a problem) or else it is Chinese of low quality and it is impossible to be sure to crimp the rubber to it without yielding.
- Crimping rings of poor quality – The requirements for steel rings are extremely high and specific. If they are too soft, they leak; they should not rust; if they are too elastic, they loosen slightly after crimping; if they are too hard, they crack when crimped. Some materials are well-crimped only with sufficiently controlled crimping speed (slow deformation) and good force control.
AirTec is committed to the quality and safety of its products. We can proudly boast that we have the most modern, safest and most precise computer-controlled hydraulic crimping machine in the world, of the absolute leader Uniflex Hydraulik GmbH.
Some of the more remarkable advantages (facilitating quality control) of Uniflex Hydraulik over other crimping machines on the market are: 
- Automatic force monitoring – in this way we immediately identify the difference in the quality of the parts used (if it is soft and of poor quality the ring will achieve the required clamping diameter with very little force and the machine will automatically report the problem)
- Automatic monitoring of the squeezing /crimping/ diameter (up to a hundredth of a millimeter) – with this function, it is impossible to over-crimmp and cut the rubber or crush other parts during squeezing.
- Automatic monitoring of the deformation rate – there are materials that require a certain rate of deformation, otherwise they crack, burst, or loosen (spring effect) after the end of pressing.
- Simultaneous comparison of the parameters: force, diameter, rate – the control is designed in such a way that if only one of the important parameters during squeezing (crimping) goes out of the norm, it automatically stops the work process, thus preventing each of the above-described potential problems in the crimping process itself.
With our machines, we leave NOTHING to chance, because quality is not achieved by chance.
(further information about our equipment is available in the ‘Service’ section)
6. Assembly and pneumatic test.
Once the air spring is ready and the electrically adjustable shock absorber has been checked (or repaired), the two are assembled into one to get the original “air strut” condition, ready to be installed back into the car. Before installation in the car, the entire part is subjected to a one-hour pneumatic test (inflation to 11 bars) in order to preventively locate an air leak (it is verified that it does not leak slightly from somewhere).
After carrying out the procedures described above, your air strut is ready for a new life.
Steps after repairing the air spring
- Careful assembly, test and final diagnostics
The new air strut is installed in the car, taking care not to damage it during installation. The use of brute force, hammers, crowbars and other tools that are always accompanied by some swear words regarding someone’s mum are absolutely undesirable. During installation, it is easy to damage the connection valve (the valve through which the air spring is filled with air), damage the control of the electronic stiffening of the shock absorber, the vehicle level sensor, etc. Quality assembly is not to be underestimated. After everything is assembled and installed correctly, a road test is done, accompanied by computer diagnostics.
All these things can be inspected and performed on-site at AirTec.
Take advantage of our package services to save unnecessary headaches, time and money while maintaining a full warranty.
