Just Sayin'

Got in the paperweight (official nickname assigned by wifey) to head into the office. Car is riding like a truck. It's so bad, I actually pulled over in my neighborhood to check for a flat tire - though it didn't feel like a flat. All tires were present and accounted for. No warning messages on dash.

Continued toward work. Determined to detour to the dealership when a small bump launched me into the headliner. Dropped car, noticing now the drivers' rear was down. Grabbed a C300 and off I go.

Two days later (no appointment...slow) car is fixed. Text on the invoice is as follows:

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Left rear air spring leaking down. Performed short test found no codes. Inspected airmatic system for leaks found left rear airspring leaking. Deactivate SBC. Release air pressure in rear air springs. Drain fuel tank. R&R both rear tires. R&R complere rear axlem (sp?). Replaced left rear air spring. Performed SBC brake bleed after repair. Reactivate SBC. Fill rear air springs. Performed alignment check. Set rear toe. Set front toe. Found no other problems after repair.

Part numbers: 211-320-13-25 Air Spring 211-328-00-58 Seal 000-989-08-07-01 Brake fluid

Hours: 9.10
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Holy cow - is this normally how much labor is required to replace a rear air spring? I know reman units can be had for ~$400, but this seems a rather involved amount of labor to install it.

What is the mortality rate on air springs? I had this same corner replaced in December 2009, and have driven the car less than 4,000 miles since. Last time it failed it had a 72 hour leak, no big deal. This time it was fine the evening before, and completely flat in the morning - wouldn't pump up.

CPO paid for the whole thing, but otherwise the bill would have exceeded $2K, I'm sure. That would be rather irritating every 6 months.

- Shadow

 

Ha, you think that's bad, you should try walking in the shoes of us guys with the hydraulic suspensions...

 

would suck more without the warranty. enjoy your car. TC

 

They have to remove the rear end to replace the rear air spring. There was a guy from Slovenia or Croatia or someplace on another forum who posted a DIY with photos on doing it without pulling the rear. It looked plausible but still labor intensive and took three people all day. But MB does it their own way and it's probably faster in the long run, who knows.

And yeah, as somebody else already said the hydraulic ABC suspension is even more of a PITA.

 

strange, I have removed the rear air springs a few times which takes 30mins at the most each side.

As stated MB delaers will have to go by the book..

 

Yes, it does

 

I found the thread again (it's on another forum) with the DIY about replacing the rear air springs and why MB does remove the rear end like the OP mentioned they did on his work order.

This guy didn't remove the rear end but it sure didn't take "30 minutes at most" for each side. It looks more complicated than that. It took him 6 hours. If he ever did it again, he said he could probably do it in 3-4 hours. Anyway, here's what he said about why MB pulls the rear.

"At this point we were able to manipulate the bag but there was a hose leading to the reservoir. It was impossible to remove the part because the hose was leading over the rear frame and that is exactly the reason why MB claims it must be disassembled and lowered down - the whole frame is holding the rear suspension. As the bag was useless at this time we decided to disassemble the hose from air spring and reservoir. This is the operation no one recommends and is also written in manual as "NOT DO THIS".

The dealer protocol is to follow MBs directions and pull the rear end and not separate the tubing from the reservoir. Apparently because the part comes with the bag, the hose and the reservoir all connected with factory clamps. There's no way you can assemble it in one piece without pulling the rear end out. They don't want you pulling the factory clamps (because of leakage possibilities later.) He did it and he pulled the tubing and clamped it off. He was using used parts and re-used the reservoir and fabricated new clamps (he also discovered that the leak was at the reservoir nipple that had corroded.)

I know the fronts are easy to do in comparison, but the rears don't seem to be. Or am I missing something here.

The only DIY with pics here on MBWorld is Yacht Master's great DIY on replacing the front struts. I don't see any about doing the rears.

I think the complexity of the unit itself is also why Arnott Industries don't offer rear replacements and sell fronts only.

Can you post a DIY maybe? Or explain how you do it? If you can do the rears in 30 minutes without the kind of labor that the OP experienced with his rears, that would be great to know.

 

Arnott does sell the rears for the Airmatic suspension.

Aaron

 

Please show me the link from Arnott for W211 rear airmatic struts.

 

I apologize, you were right, they don't have them. I could have sweared i saw all four corners listed. It must have been on another site i didn't save or something, now i am going crazy trying to find them.

Aaron

 

Unfortunately you won't find them anywhere. MBWorld members have been through this.

I called Arnott several months ago and they said they hope to come out with rears but were doubtful about it.

Arnott does have the older (pre-2007) S airmatic, and also SL ABC rears. Maybe that's what you saw.

 

Yeah it is possible i was looking at the wrong model car.

So basically if the rears need replacing, you have to purchase from the dealer for ~700ea then.

Aaron

 

Good info, thanks. I've stumbled across the writeup on replacing the fronts, looks to be an easy enough job.

On my recent replacement of the rear struts, the dealer techs must have significant shortcuts. At the end of day 2 the dealer was waiting for the part to arrive. I'm assuming it came in the first shipement on day 3 (we have an MB parts depot near DFW airport, ~30 minutes from the dealer). Despite the 9.1 hours of labor, the car was ready before noon, and that included followup visits to the alignment rack and wash.

I suppose the tech could have left the car partially disassembled on the lift overnight. But typically they won't tie up workspace waiting for a part. My guess is that after diagnosis, the strut replacement required 3-4 actual hours of labor - inline with what was stated previously in this thread.

 

fwiw, I spoke to my SA today (about something else) and asked about rear replacements. He said that to get rebated under warranty from MBUSA, that they have to do it following strict protocol. And that means pulling the rear end.

Here's from another forum:

"My rear air springs were replaced under the cpo warranty 2 months ago. I spoke to the service mgr when they were doing the work. They did pull the entire rear out of the car for the reasons you identified. That is the way the dealer does the work, I can't imagine them doing it this way if there were a faster method."

It was in response to this post:

"The rear Airmatic air springs seem to present a much more difficult repair method. It is suggested in WIS that for a proper repair to be made, the entire rear axle and cradle must be lowered from the car. Their reasoning for this is that the hose from the accumulator must not be disconnected from the air spring. They state that leaks will result if this is done. I have read in more than one place that disconnecting the the hose is no big deal, and successful replacements have been done this way. If the hose is disconnected, then the spring can be dismounted and replaced with a new one without having to dismantle the entire rear end. After the new one is in place, bolted down, plumbing & wires are connected, then let the air pressure build so that the spring can support the weight of the car.

If air leakage at the point of connection between the hose and barb on the air spring are the reason for having to drop the entire rear end, then with current technologies, could we not use something other than a worm drive band clamp that would effect a leak free joint? If this were the case, then we could quite easily perform the rear air spring replacement ourselves, and skip the horrendous dealership bill."

Since another poster (£ C43 £ AMG £) said (in this thread) that he can do the rears himself in 30 minutes, I wish he would tell us how. It would benefit everybody here and add much to the database. He said he's done it "a few times" so maybe he could post a DIY walk through.

 

I would also like to know how he is able to do the rears in roughly that time frame. I am sure there has to be shortcuts in doing this as the time and quote from Mercedes and a private shop are significantly different. $700+ from Mercedes on labor for the rears, and pretty much about $300 from the private shop.

Also, i was asking a private car dealer about a "hook up" on some mercedes parts, particularly the rear shocks, and he said he can get them for $550 each. Does anyone have any other places that can get them for near that? If he can actually get them for that price as he says, does anyone else want some as well? If i pull the trigger on this, i will more than likely do it today. So the airbag portion of the airmatic suspension is a separate component from the actual shock on the rears and not like the fronts?

Aaron