Hi all. I am trying to figure out if my pump has lost peak performance on my 01' s430. It was replaced few years ago. I run the 'fill reservoir' test in my scan tool and it seems to be able to fill up about 12 bar of pressure within 15-20 seconds. I 'heard' , but cannot confirm, it should be 13-16 bar within 40 seconds. There are no codes in the airmatic system, the only thing that makes me suspect pump is weak is because when I hit the airmatic button to raise me up, it says 'Airmatic rising' like forever. It may take 10 minutes to disappear, but the front struts do lift up.

 

Hi, could be that piston rings itself are worn out.