Is there an air suspension malfunction warning on your Mercedes-Benz dashboard, and the height of your vehicle is uneven? Learn how to fix the problem by replacing your Mercedes-Benz rear air strut.
This guide provides instructions on replacing the rear air strut on the Mercedes Benz W221, S500, S550, C216, CL550, RWD, and 4WD models. Replacing the rear air suspension strut on a Mercedes Benz S-Class rear-wheel-drive W221 chassis is relativity easy and takes about two hours.
Common symptoms indicating a bad Rear Air Suspension Strut of your Mercedes Benz
- Air suspension malfunction warning on dashboard.
- Leaks, air leaking in the connection points.
- Uneven height on the rear side of the vehicle.
- You will notice a significant change in riding quality.
- The car leans too much when going to corners.
What you will need
- W221 Rear Air Suspension Strut
- Metric Tool Set
- Torque Wrench
- Pry Bar
- Penetrating oil
- Screw Driver
- 18mm Wrench
- M14 spline bit
Follow these steps in replacing the rear air suspension strut on the Mercedes Benz.
- Park the vehicle on level ground and set the parking brakes.
- Use a wheel chook to block the front wheels to prevent the vehicle from rolling.
- Disconnect the negative terminal of the battery. In 2009 and newer models, the battery is located behind the rear seat and can be accessed via the trunk. In previous models, the battery is in the engine bay, passenger side.
- Loosen the wheel studs. Note that your S-Class may have unique wheel studs, requiring a 17mm flower head socket.
- Lift the vehicle to your preferred height.
- Remove the wheel.
- Spray penetrating oil to the lower control arm bolt, air strut mounting bolt, and stabilizer link bolts.
- Remove the stabilizer link nut that connects to the lower sway arm, separate the two and remove the stabilizer link.
- Using two 18mm wrenches, remove the lower control arm bolt
- Using two 18mm wrenches again, remove the air strut lower mounting bolt.
- Install a jack stand and support the lower control arm.
- Using the 10mm socket, remove the plastic molding bolts that cover the air strut.
- Pry parts of the inner wheel liner so that you will have access to remove the metal clip. Pull out the air strut and wheel speed connectors.
- Go inside the vehicle and remove the rear dash cover.
- Remove the small piece of foam insulation that is covering the air strut upper mounting. Remember, it is not necessary to remove the whole rear insulation.
- Remove and secure the strut’s airline hose.
- Remove the three 13mm air strut upper mounting nuts.
- Go back to the strut.
- Remove the jack stand supporting the lower control arm.
- Push the lower control arm downward and pull out the air strut out
- Install the new air strut correctly, and use a jack stand to support the lower control arm.
- Install the lower control arm and air strut lower mounting bolts, then tighten them to the specified torque.
- Reconnect the lower sway arm and stabilizer link and tighten it to the specified torque.
- Reconnect the air strut and wheel speed connectors and install the metal clip. Make sure that the wiring harness is in the correct routing.
- Install the plastic molding and tighten the 10mm bolts.
- Return the inner wheel liner to its original position.
- Install the wheel and tighten the lug nuts to the specified torque.
- Install the three 10mm bolts to the air strut upper mounting and tighten them to the specified torque.
- Remove the old airline inlet fitting from the airline hose.
- Install the new airline inlet fitting.
- Clean and inspect the airline hose before installing it.
- Install the airline hose to the new fitting and make sure that it locks in place so that the airline hose should not pull out.
- Return the small foam insulation covering the air strut upper mounting.
- Install the rear dash cover.
- Lower the vehicle and reconnect the battery terminal.
- Start the engine, then wait for two minutes.
- Test the functionality of the new air strut.
- Check the air strut for leaks.
- It is recommended that you should go for a re-alignment every time this procedure is performed. It is for the safety and better performance of the vehicle.
Mercedes-Benz S-Class W221
Applicable to Airmatic(RWD), 4Matic(4WD), and AMG Model.
- S350 Base Sedan 4-Door 3.5L 2012-2013
- S350 Base Sedan 4-Door 4.6L 2012-2013
- S350 Base Sedan 4-Door 5.5L 2012-2013
- S350 Bluetec 4Matic Sedan 4-Door 3.0L 2012-2013
- S400 Hybrid Sedan 4-Door 3.5L 2010-2013
- S450 4Matic Sedan 4-Door 4.6L 2008-2011
- S500 Base Sedan 4-Door 5.5L 2007-2011
- S550 4Matic Sedan 4-Door 4.6L 2012-2013
- S550 4Matic Sedan 4-Door 5.5L 2007-2011
- S550 Base Sedan 4-Door 4.6L 2012-2013
- S550 Base Sedan 4-Door 5.5L 2007-2011
- S600 Base Sedan 4-Door 5.5L 2007-2013
- S63 AMG Base Sedan 4-Door 5.5L 2011-2013
- S63 AMG Base Sedan 4-Door 6.0L 2010-2012
- S63 AMG Base Sedan 4-Door 6.2L 2009-2013
- S63 AMG Base Sedan 4-Door 6.3L 2008-2010
- S65 AMG Base Sedan 4-Door 6.0L 2007-2013
Mercedes-Benz CL-Class C216
Applicable to Airmatic(RWD), 4Matic(4WD), and AMG Model.
- CL500 Base Coupe 2-Door 4.7L 2013
- CL500 Base Coupe 2-Door 5.5L 2007-2012
- CL550 4Matic Coupe 2-Door 4.6L 2011-2014
- CL550 4Matic Coupe 2-Door 5.5L 2009-2010
- CL550 Base Coupe 2-Door 5.5L 2007-2008
- CL600 Base Coupe 2-Door 5.5L 2007-2014
- CL63 AMG Base Coupe 2-Door 5.5L 2011-2014
- CL63 AMG Base Coupe 2-Door 6.0L 2010-2012
- CL63 AMG Base Coupe 2-Door 6.2L 2008-2011
- CL63 AMG Base Coupe 2-Door 6.3L 2008-2010
- CL65 AMG Base Coupe 2-Door 6.0L 2008-2014
- CL65 AMG Base Coupe 2-Door 6.2L 2009
The possible part number for Mercedes-Benz W221 rear air strut:
There may be other parts numbers.
Frequently Ask Questions
How much does it cost to replace a Mercedes Benz air strut
- The average cost to replace a Mercedes Benz Rear Air Strut Suspension is between $500 and $800. Labor costs are estimated between $125 and $250, while parts are priced between $350 and $700.
How long does a Mercedes Benz Air Strut Suspension last?
- The average life span of an air strut suspension is about fifteen years or more it depends on how much load the vehicle carries on a day-to-day basis and what terrain it usually drives into. It is not unusual for the air strut to fail only after seven years of service.
- Mercedes Benz Rear Air Suspension Strut Replacement Cost -ebay.com
- How long does airmatic suspension last – benzworld.org
We hope you find the Mercedes Benz S-Class W221 CL-Class Rear Air Strut Replacement guide helpful. Check these troubleshooting and repair guides for more help on your Mercedes-Benz.