Introduction：

Two front Air Suspesnion shock absorbers are connected from the front suspension to the chassis, and 
two rear Air Suspension shock absorbers are attached between the rear suspension and the chassis. Shock 
absorbers have three main purposes:
 1. They control spring action and oscillations to provide the desired ride quality.
 2. They help prevent body sway and lean while cornering.
 3. They reduce the tendency of a tire tread to lift off the road, which improves tire life, traction, and directional stability.
Because Air suspension shock absorbers control spring action, spring oscillations, and chassis oscillations, they contribute to vehicle safety and passenger comfort. If the shock absorbers are 
worn out, excessive chassis oscillations may occur, particularly on rough road surfaces. Th ese 
excessive chassis oscillations may result in loss of steering control. Worn-out shock absorbers 
also cause excessive body lean and sway while cornering, which may cause the driver to lose 
control of the vehicle. Shock absorbers are extremely important to providing longer tire life 
and improving vehicle handling, steering quality, and ride quality.
Air suspension Shock absorber design is matched to the defl ection rate of the coil spring to control the spring 
action. Several diff erent types of shock absorbers are available for special service requirements.

Fitting the Following vehicle:

MERCEDES-BENZ CLS400 2015-2017 4Matic
MERCEDES-BENZ CLS550 2012-2018 4Matic
MERCEDES-BENZ CLS63 AMG 2014-2018 4Matic
MERCEDES-BENZ E250 2014-2016 4Matic
MERCEDES-BENZ E300 2012-2016 4Matic
MERCEDES-BENZ E350 2010-2016 4Matic
MERCEDES-BENZ E400 2015-2016 4Matic 
MERCEDES-BENZ E550 2010-2016 4Matic
MERCEDES-BENZ E63 AMG 2014-2016 4Matic

Evolution Related：

Mercedes-Benz E-Class
W124 First generation (1993-1995)
W210 Second generation (1996-2002)
W211 Third generation (2003-2009)
W212 Fourth generation (2009-2016)
W213 Fifth generation (2016-present)

Mercedes-Benz CLS-Class
W219 First generation (2004-2010)
W218 Second generation (2011-2018)

C218 4-Door Coupe
X218 5-Door Estate With Shooting Brake
C257 Third generation (2019-present)

Platform Drive Layout:

4 Wheel Drive Layout

Advantage of Our Air Suspension:

-The Original Size
-Direct Replacement
-Perfect Fit
-Safe and Stable
-Longer Life

-Eliminating abnormal sound
-After-sales Guarantee

-Made of high quality raw materials, effectively reduce air leakage, strong sealing
-All parts are hand inspected off the line before packaging and once again by our team before shipment

-It has a high compressive strength and good sound insulation to ensure our driving comfort and safety

If you are interested with any other suspension parts, please click and save our store

When Should We Replace Air Suspension:

• The car was subjected to excessive up, down, and left/right vibrations, nods during braking, and irregular tire wear
• An excessive tilt or swing of a car in a turn
• Wear or damage of final assembly housing, resulting in oil leakage of air suspension and affecting its performance
• If the car vibrates violently when it comes to an emergency stop while moving slowly

Common Air Suspension Failure Inspection:

1.Abnormal Sounds
When the air suspension strut is damaged,it will give out an abnormal sound.
2.Poor Handling Stability
When the car passes over a rough road ,it bumps and cannot keep steady.
3.Air Leakage 
Leaking air、seal gasket failed.
4.Car Body Slant
Under the condition of poor road (Bumpy Road),the body will collapse.
5.Irregular Tire Wear 
The air suspension sturt needs  to be replaced if tyre surface has uneven wear marks.
6.Over Bend
When you turn to brakes,tilt faster and the steering wheel will fail. 

Recommended replacement cycle:
Since the average annual distance of the car is 20,000 kilometers,  the replacement frequency is obtained every 4 years or 80.000km. In fact, the replacement frequency will vary depending on the car condition, road condition and shock absorber manufacturer.When driving a certain number of kilometers, we should take corresponding measures to ensure our driving safety.

• 20.000km: Please check your air suspension
• 80.000km: Need to replace your air suspension
• 100.000km: Please replace your air suspension as soon as possible

OEM Part Number:

A2123208213 A2123202038 A2123203438

2123202038, 2123203438, 2123208213

212320343860, 212320343880, AS-3424

Air Suspension Shock Absorber Operation:

Air Suspension Shock absorbers are usually mounted between the lower control arms and the chassis. When 
a vehicle wheel strikes a bump, the wheel and suspension move upward in relation to the 
chassis. Upward wheel movement is referred to as jounce travel. Th is jounce action causes 
the spring to deflect or compress. Under this condition, the spring stores energy and springs 
back downward with all the energy absorbed when it defl ected upward. Th is downward spring 
and wheel action is called rebound travel. If this spring action were not controlled, the 
wheel would strike the road with a strong downward force, and the wheel jounce would occur 
again. Th erefore, some device must be installed to control the spring action, or the wheelwould bounce up and down many times after it hit a bump, causing passenger discomfort, 
 directional instability, and suspension component wear.
Shock absorbers are installed on suspension systems to control spring action. When a wheel 
strikes a bump and jounce travel occurs, the shock absorber lower tube unit is forced upward. 
Th is action forces the piston downward in the lower tube unit. Since oil cannot leak past the 
piston, the oil in the lower unit is forced through the piston orifi ces or valves to the upper oil 
 chamber. These valves provide precise oil fl ow control and control the upward action of the wheel 
and suspension, which is referred to as a shock absorber compression stroke (Figure 5-2).
When the spring expands downward in rebound travel, the lower shock absorber unit is 
also forced downward. When this occurs, the piston moves upward in the lower tube unit, 
and hydraulic oil is forced through the piston orifi ces or valves from the upper oil chamber to 
the lower oil chamber. Since the valves restrict oil flow with precise control, the downward 
suspension and wheel movement is controlled.
When the shock absorber piston moves, oil is forced through the piston. Since the piston 
valves and orifi ces resist the fl ow of oil, friction and heat are created. Th e resistance of the oil 
moving through the piston must be calibrated as closely as possible to the spring’s deflection 
rate or strength. Wheels and suspension systems defl ect at many diff erent speeds, depending 
on the type and size of bump and the vehicle speed. Th e resistance of a shock absorber piston 
increases with the square of its speed. For example, if the wheel defl ection speed increases 
four times, the piston resistance is sixteen times as great. Th erefore, if a wheel strikes a large 
bump at high speed, the wheel defl ection and rebound can be eff ectively locked by the shock 
absorber. Shock absorber engineers prevent this action by precisely designing shock absorbervalves and orifi ces to provide enough friction to prevent the spring from overextending on 
the rebound stroke. Th ese piston valves and orifi ces must not create excessive friction, which 
slows the wheel from returning to its original position.
Shock absorber pistons have many diff erent types of valves and orifi ces. In some pistons, 
small orifi ces control the oil flow during slow wheel and suspension movements. Stacked steel 
valves control the oil fl ow during medium speed wheel and suspension movements. During 
maximum wheel and suspension movements, larger orifi ces between the piston valves provide oil fl ow control. On other shock absorber pistons, the stacked steel valves alone provide 
oil flow control. Regardless of the piston orifi ce and valve design, the shock absorber must be 
precisely matched to absorb the spring’s energy.
During fast upward wheel movement on the compression stroke, excessive pressure in 
the lower oil chamber forces the base valve open and thus allows oil to fl ow through this valve 
to the reservoir. Th e nitrogen gas provides a compensating space for the oil that is displaced 
into the reservoir on the compression stroke and when the oil is heated. Since the gas exerts 
pressure on the oil, cavitation, or foaming of the oil, is eliminated. When oil bubbles are 
eliminated in this way, the shock absorber provides continuous damping for wheel defl ections as small as 0.078 in (2.0 mm). A rebound rubber is located on top of the piston. If the 
wheel drops downward into a hole, the shock absorber may become fully extended. Under 
this condition, the rebound rubber provides a cushioning action.

Package Includes:

Single for Front Right Air Suspension Shock Strut

Notes: 

Of all the suspension components, shock absorbers and struts 
contribute the most to ride quality. As the vehicle is driven over road irregularities, 
the shock absorbers or struts are continually operating to control the spring action 
and provide acceptable ride quality. It has been my experience that shock absorbers 
and struts usually wear out fi rst in suspension systems, because they are working 
every time a wheel strikes a road irregularity. Th erefore, you must understand not only shock absorber and strut operation but also how ride quality is aff ected if these componen

• Please double confirm the compatibility as well as the OEM number before purchasing.
• Instruction is not included. Professional installation is recommended.