What you will need
How to change Mercedes X164 / W251 Rear Suspension Air Bag
- Park the vehicle on level ground and set the parking brakes.
- Loosen the lug nuts for the rear wheel but do not remove the lug nuts yet.
- Jack up the vehicle and secure it with jack stands.
- Remove the wheel.
- Remove the air line nut of the back of the airbag.
- Use a flathead screwdriver to pry down the airbag.
- Lift the airbag and pull it out of the vehicle.
- Remove the white plastic piece at the frame by turning it counterclockwise. Install the new white plastic. If the black O ring from the old air strut is stuck on the white pice, remove and discard it. The new airbag will have the black O ring installed in it.
- Install the new airbag and push it up to lock it on the white plastic piece.
- Replace and reinstall the airline nut. Inspect the rubber o-ring on the nut. Do not overtighten the copper nut.
- Install the wheel and slowly lower the vehicle.
- Start up the engine and allow it to rise. This can take up to five minutes.
While in most cases, the vehicle will raise up and level on its own, we had to use a Mercedes-Benz OBD-II Scanner to raise up the rear and level the vehicle.
- W164 ML320 ML350 ML450 ML550,
- X164 GL320 GL350 GL450 GL550,
- W251 A251 R320 R350 R550 R500 R63 AMG
Applicable mainly to 2006 to 2012 model years.