Rear Airmatic Suspension
Thread Starter
Newbie
Joined: Nov 2015
Posts: 5
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W220 2003 Mercedes-Benz s430 4matic
Rear Airmatic Suspension
Hi Everyone,
So I have a 2003 s430 4matic and last year during the winter we noticed that in freezing temperature of about -15C the car was slammed and wouldn't rise unless it was in direct sunlight for a while or in a heat garage. Seeing how winter is coming up we want to replace the rear suspension but don't want to break the bank. We have been looking for parts on ebay and what not. Ive noticed that the 4matic cars require a different strut than non 4matic cars.
Was wondering if someone could clarify why that is?
Thanks
So I have a 2003 s430 4matic and last year during the winter we noticed that in freezing temperature of about -15C the car was slammed and wouldn't rise unless it was in direct sunlight for a while or in a heat garage. Seeing how winter is coming up we want to replace the rear suspension but don't want to break the bank. We have been looking for parts on ebay and what not. Ive noticed that the 4matic cars require a different strut than non 4matic cars.
Was wondering if someone could clarify why that is?
Thanks
Member
Joined: Nov 2012
Posts: 220
Likes: 2
From: New England
2006 S430 4Matic
I suggest before you start asking questions you search through and read the start here thread for some background on the suspension systems used in these vehicles. If members see that you have put forward an effort to understand your problem they will be more willing to put their time into helping you answer your questions and resolve your issues.
There are two primary suspension systems used on the W220, Hydraulic, and Airmatic which are both active systems. Your car has the Airmatic struts. There are threads which explain how the system works and what its components are go to the start here thread.
Welcome to the forum.
There are two primary suspension systems used on the W220, Hydraulic, and Airmatic which are both active systems. Your car has the Airmatic struts. There are threads which explain how the system works and what its components are go to the start here thread.
Welcome to the forum.
Senior Member
Joined: Apr 2012
Posts: 432
Likes: 96
From: Just north of Detroit,Michigan
2012 E350 4Matic P2
If your system is working properly during warmer weather and if you just go in and replace the rear struts, you may be be throwing away good parts and still have the same issue.
Good Luck,
Bob
MBWorld Fanatic!
Joined: Jan 2014
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From: Republic of Texas
'99 and '05 E55 AMG
Do not forget about thermal coefficient of expansion. Rubber, metal, and plastic expand and contract at different rates. In my case, the rubber hose was old and no longer conformed to the plastic housing when cold. When warm, no issue. Search. Lots of info on this subject and how to find the leaks.
Thread Starter
Newbie
Joined: Nov 2015
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W220 2003 Mercedes-Benz s430 4matic
I have the same thing happening on my rear struts. I have changed several parts ie Control Module and Valve Block and still no joy. I came to the conclusion that I might be accumulating moisture in the system which would ice up the valves for the rear struts. This past summer, I removed the pump and replaced the desiccant in the air dryer, (my write up here) . I will know whether I solved my problem during this next winter.
If your system is working properly during warmer weather and if you just go in and replace the rear struts, you may be be throwing away good parts and still have the same issue.
Good Luck,
Bob
If your system is working properly during warmer weather and if you just go in and replace the rear struts, you may be be throwing away good parts and still have the same issue.
Good Luck,
Bob
Hi Bob,
Just wondering if you had any problem so far this winter, or if your fix helped.
I replaced both rear strutts, and check the pump, valve block and check for leaks. the car still drops in the cold weather especially on the left side. Also when there is more weight (just passangers in the back) the car gets low to the point its says its to low?
Any thoughts, Thanks
Dave
Senior Member
Joined: Apr 2012
Posts: 432
Likes: 96
From: Just north of Detroit,Michigan
2012 E350 4Matic P2
Hi Bob,
Just wondering if you had any problem so far this winter, or if your fix helped.
I replaced both rear strutts, and check the pump, valve block and check for leaks. the car still drops in the cold weather especially on the left side. Also when there is more weight (just passangers in the back) the car gets low to the point its says its to low?
Any thoughts, Thanks
Dave
Just wondering if you had any problem so far this winter, or if your fix helped.
I replaced both rear strutts, and check the pump, valve block and check for leaks. the car still drops in the cold weather especially on the left side. Also when there is more weight (just passangers in the back) the car gets low to the point its says its to low?
Any thoughts, Thanks
Dave
Dave,
Mine has been staying up so far this winter. No drooping at all. This has been an unusually mild winter so far in Mich. so the next couple of months may tell a different story, we'll see. I know replacing the pump piston ring and replacing the desiccant can only be a positive.
Drooping more on one side than the other suggests that you have a circuit leak on that side. Mine was drooping equally in the rear. Since you have replaced both struts in the rear then theoretically you should be able to rule out a leaking strut although it is in the realm of possibilities that the replacement has failed but I would look beyond that for now.
Two things to consider. Your valve block is not sealing properly or that your pump is not putting out enough volume and pressure. If you can hookup to an SDS setup, you could exercise both those components to verify if either or both have or are failing.
As I mentioned earlier, I changed out my valve block and it did not solve my problem. You can check out my posts on Benzworld. Also, have you read through the encyclopedia in the stickies?? I know how frustrating this all can be, I lived it!
Finally, you do not have to remove the air pump to replace the piston ring. I changed my ring back to the old one this summer chasing another issue thinking that the pump had failed but found out the pump was not the issue. I then re-installed the new ring. All you have to do is remove the air line from the head to the air dryer and then take the two screws out of the head and drop the head air dryer assembly down to expose the piston. All this done right under the car without removing the pump. Something to consider.
Anyway, good luck,
Bob
Last edited by mercy-me; Jan 7, 2016 at 08:26 AM. Reason: clarity
