Does your Airmatic equipped car look like this?
The first thing you need to do before replacing the compressor is to make sure you don’t have any leaks. A leak in the system is likely what caused your compressor to fail in the first place A leak in the system will require the compressor to run longer and more often to maintain pressure in the system. This puts too much stress on the compressor and eventually it fails. Check your strut tops with soapy water, check the valve block, and make sure there are no leaks. If your compressor is completely dead or extremely weak, you will need to replace the compressor first and then check for leaks. Fix any leaks before driving or your new compressor will fail as well.
This job doesn’t take too long. Maybe 2 hours for your first time doing it. That includes checking for leaks.
This compressor is rather expensive from Mercedes, somewhere around $350. We have had bad luck with the cheap units from eBay. We’ve had a couple that were really noisy right out of the box and one that was DOA. They have always been replaced under warranty and they seem to last once installed but it’s always a risk installing cheap parts so weigh your options and make a decision knowing that you may end up with a DOA pump or a noisy pump that will need to be exchanged. We use the Wabco brand pumps from Germany whenever cost is a concern. They run about $260 so a little cheaper than Mercedes but still high quality.
We use a lot of Mann filters. They work well and they are priced reasonably. You definitely want a new filter installed at the same time as your new pump.
Photos of the procedure originally provided by “eric242340” on benzworld forums.