Mercedes AirMATIC Suspension Compressor Replacement Instructions

Published by YOUCANIC Automotive Experts 
Last Updated Nov 28, 2018 

In this guide, you will find step-by-step instructions on how to replace the air suspension compressor on Mercedes-Benz vehicles equipped with air (airmatic) suspension. Replacing Mercedes suspension air compressor is an easy procedure that can be performed by the vehicle owner in one hour.  

What you will need

mercedes air suspension compressor

Mercedes Air Suspension Compressor

Symptoms of defective Mercedes-Benz air suspension compressor

  • Mercedes-Benz Sagging on all four corner
  • Airmatic Malfunction Message
  • Airmatic Visit Workshop Message
  • Fault pointing to any of the following
    • A9/1 Airmatic compressor unit
    • A9/1m1 Air compressor motor
    • A9/1y1 Airmatic pressure reduction valve

Example Faults:

  • 5350 A9/1y1 (AIRmatic pressure release valve): Open Circuit.

Tools you will need

 Tip

It is highly recommended to replace the Mercedes air compressor relay at the same time that you replace the air compressor. 

Instructions

Below you will find instructions on how to replace Mercedes airmatic compressor. These instructions apply to most Mercedes-Benz models. The air compressor can be found on the right (passenger) front corner of the vehicle behind the bumper. It is in this location on most models including E, ML, GL, S, CLS class etc. 

Raise Vehicle, Remove Splash Shield

Remove black plastic panel under the engine. There may be as many as 3 panels under the car. You need to remove the first panel, right after the front bumper. Once you remove the panel you will see the air compressor right behind the front bumper, underneath the headlight on the passenger side. For demonstration purposes, we are showing pictures with the bumper removed. You do not need to remove the front bumper.

Mercedes air compressor replacement

Disconnect Air Line

Remove the plastic airline that goes into the air compressor. Using a 12 mm wrench, turn the bolt counterclockwise. Once the bolt is loose, pull out the airline. There is a small rubber gasket on the metal connector at the end of the threads, make sure not to damage it. 

disconnecting air line

Disconnect Electrical Plugs

Unplug two electrical connectors that go to the air compressor. 

disconnect plugs from the air compressor

Remove three 8 mm nuts

Remove three nuts that hold the air compressor in place using 8 mm deep socket. You may want to spray penetrating oil on the nuts before you remove them. The bolts can easily break if they are rusted.

remove 3 8 mm nuts

Disconnect air inlet hose

Remove the hose that connects to the intake air filter. Using your pliers slide the clamp over then pull on the rubber hose. 

Replace air compressor

Remove the air compressor unit. Install the new compressor. Assemble in reverse order.

replace the air compressor mercedes c e s ml gl r g cls class

Troubleshooting Tip

Mercedes-Benz air suspension compressor may fail and no longer turn on. The motor which is part of the air compressor often sizes and will no longer run even if you feed 12 volts directly to the air compressor. 

mb air compressor suspention airmatic

In a few cases, the compressor may still run (seem to be working) but it will not generate the required pressure. In such cases, the vehicle may only partially raise and you will get an air suspension message on the instrument cluster.

Before you proceed with the replacement of the air suspension compressor, inspect the wires that go to the air compressor for damage. Also, check for a bad connector at the air compressor. Check the air compressor relay to ensure it is working properly. 

Mercedes Models with Airmatic Suspension

Mercedes-Benz installed airmatic suspension on many models. Below is a list of models that have airmatic. 

  • E-Class,
    • E320 E500 E55 E600 E350 
  • S-Class
    • S430 S500 S550 S600 S63 S55 AMG
  • R-Class,
    • R320 R350 R500 R63 AMG
  • ML-Class,
    • ML350 ML500 ML63 AMG
  • CL-Class,
    • CL550 CL600
  • GL-Class,
    • GL450 GL550 
  • SL-Class, 
    • SL350 SL500 SL600 SL55 SL63 AMG
  • CLS-Class
    • CLS500 CLS55 CLS63 AMG

This is a partial list of the most popular models with air suspension (airmatic). There are other models that have airmatic suspension which often on some models (such as C, E Class) is an additional option and doesn't come standard. 

DIY Cost
$200-$320
Mechanic
$850-$1100
Dealer
$950-$1200