Originally Posted by duxthe1

On that car there is a shutoff valve in each strut or airbag. If it leaks down when sitting, its safe to assume its a bad bag or strut on whatever corner goes down.

Keep in mind that even good struts and bags will leak down eventually, too. Mercedes has a spec of "its ok to fall down after so many days." I don't recall off hand how many but more than just a few.