NorsemanE320

I forlot to tell that i've changed both front struts and both rear bags. Every time the car lowered in the same corner the leak was. My compressor have never been changed since the car was producer in dec 2003. But can error also be because of a faulty sensor??

equitiesguy

With the car hot after a drive, tell the car to "raise" with the switch. You'd be surprised how easy it is to discover leaks this way. If it's leaking enough to hiss, and it isn't just the car self leveling or kneeling then you should be able to hear it when it's up in the air. Frankly, if it's leaking that bad then it would probably go right down on to the stop.

Have the car scanned with STAR before you start going off the deep end.

Yuille36

The air compressor shouldn't be the cause of the leak, as it just supplies air to the tank in the trunk. Then the air that comes from the tank is routed thru the air distribution block.
The leveling sensors along with air pressure sensors in the struts/airbags are telling the computer where air is needed, thus triggering the air distribution block to release the air to whatever corner(s).
One would only replace the air compressor if it craps out on you. That is my understanding of the air system, explained to me by a AMG technician.

equitiesguy

Edited.

Yuille36

I'm not saying that your wrong. But an AMG technician explained this to me years ago. So, my information maybe flawed.
But I find it odd, that my front struts, aren't necessarily getting its air from the air compressor, if their is sufficient air in the tank.
As there are many time, where I raised the car the compressor never kicked on. And that would mean, that there is a pressure sensor attached to the tank telling the compressor that more air is needed.
And, I also think that the fronts get air either from the tank or the compressor, depending on how much air is in the system.

equitiesguy

I'm completely wrong. The lines from the front struts run directly to the pump, but apparently there is a charge valve located at the pump itself (Y36/6) with four lines that run from the rear reservoir. I never realized they had four lines running all the way from the rear reservoir back to the pump. For some reason I thought it was only the two for the rear.

The weird thing is I remember trying to raise one of my struts after installing a replacement (only to find the new part was DOA) and it would turn on the pump in order to pressurize it. I've never seen the front struts drain the rear tank when they're leaking or having an issue. The rear tank stayed at 17~ bar even while the pump was raising the front (and subsequently leaking).

I question when the tank actually provides supply to the fronts.

Yuille36

What I do know is that, the air in the tank runs directly to the charge valve aka air distribution block, and that charges the struts and the bags. But I also believe that the engineers added a redundancy to charge the struts or the bags directly from the pump. This system is overly complicated, and difficult to figure out without Star.

equitiesguy

Difficult to diagnosis without DAS. Easy enough to understand with WIS. I think the return lines from the rear tank are strictly for self leveling, the more I dive into it.

If you're looking for a leak, there's no better way than to bring up the airmatic computer module and watch the pressures. If it holds, it's not leaking. If it doesn't, it is.