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 W251 R-Class
Mercedes-Benz R320 2007-2009
Mercedes-Benz R350 2006-2013
Mercedes-Benz R500 2006-2008
Mercedes-Benz R550 2008
Without Adaptive Damping System
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:
2513200631,2513201431
2513201931,2513202931
2513203031,2513200931
2513201031,2513201531
2513201831,2513202231
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:
Pair for Rear Left and Right Air Suspension Shock Struts
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.
