Rear shock on 2013 SL63 "misting"

[RussJ]

According to the MOT guy, my SL63 rear offside shock is "misting", ie a very small leak.
There are no symptoms other than a smear of hydraulic oil around the bottom fixing.
There doesn't appear to be any repair kits so I'm expecting to have to replace the shock which is a shame as the car has only done 20k miles.
I looked up the job in WIS and it doesn't look too daunting but I wondered if anyone else has done this job and if there are any issues I should be aware of?
One item that I think I may need is a special tool to release the hydraulic connection?
Would appreciate any advice...
Russ

 

[jasonh]

Really you need to replace both sides.

When a shock actually fails I have seen main dealers replace just one side, usually when they're paying under warranty. But in their defence being under warranty means the car is fairly new.

Your shocks are 11 years old and a brand new one is likely to have different/better damping characteristics that the old one on the other side. That can compromise the handling.

Regarding shocks "misting" I've seen service bulletins (for BMWs) stating that "misting" is acceptable and that there is no claim to be made under warranty.

So I'd suggest you have two options:

1) Live with it for now
2) Replace both shocks

Because of the car it is, and I suspect you're like me, option (1) is going to niggle away at you, so it really needs to be option (2).

 

[Will]

Are they shock absorbers though, or hydraulic struts/rams?

I thought the AMG SL of that era had ABC (hydraulic suspension) - if so the pressure spheres/accumulators/spring cells are what provide the shock absorption? The parts that look like shock absorbers just extend/retract to set the ride height and allow the movement of fluid through the system, in/out of the accumulators to allow for movement and provide damping.

In other words, you can easily replace them one at a time. They can only really fail by leaking through the seals as maybe the case here, or if the mountings/bushes/joints wear out.

Worth doing a bit of research though as I would imagine they would be quite expensive. In terms of fitting you need to understand how the system works first (if the 2013 SL63 does indeed have ABC!)

 

[Jobsworth]

They are quite common for leaking on the R231. They are ABC struts. What usually happens is the hydraulic hose rubs against the plastic gaiter, wears a hole and dirt gets in. Dirt damages the seals and they leak. I’ve seen them fail under 20k miles.

 

[RussJ]

Thanks for responses. I should have used "strut" rather than shock to avoid confusion.
I found a video on Youtube showing how to remove and refit the strut (3 nuts at the top, one bolt at the bottom and the hydraulic hose connection), which looks do-able.
My main concern is the hose connection. Can't find any specific "how to's"and its not clear in the video.
Can anyone offer some practical advice or perhaps loan or sell me the special tool?

 

[mattk1]

Hi Russ, my first thought would be to have a chat with your local indie. I would highly recommend the guys at PCS who have looked after mine, and many other's cars on here, for a number of years & all of mine have had the 'ABC' suspension system. You might even be surprised how cheap they could be. Good luck.

Kind regards Matt

 

[Jobsworth]

I can’t recall exactly how, but I dismantled the connection with no special tools. They don’t have a bleed point like the older r230, which concerned me initially, but it self bled a bit immediately and the last bit within 200 yards of driving

 

[DSM10000]

Thanks for responses. I should have used "strut" rather than shock to avoid confusion.
I found a video on Youtube showing how to remove and refit the strut (3 nuts at the top, one bolt at the bottom and the hydraulic hose connection), which looks do-able.
My main concern is the hose connection. Can't find any specific "how to's"and its not clear in the video.
Can anyone offer some practical advice or perhaps loan or sell me the special tool?

If you do not fancy doing this yourself then I can highly recommend this garage :

HOME | mysite

www.headlandsgarage.com

Pete Nicklin the owner is ex Mercedes and very experienced

 

[AMGeed]

Thanks for responses. I should have used "strut" rather than shock to avoid confusion.
I found a video on Youtube showing how to remove and refit the strut (3 nuts at the top, one bolt at the bottom and the hydraulic hose connection), which looks do-able.
My main concern is the hose connection. Can't find any specific "how to's"and its not clear in the video.
Can anyone offer some practical advice or perhaps loan or sell me the special tool?

Star Tech down at Creekmore Industrial Estate will do that for you if you don't fancy it Russ.

Star Tech | Mercedes-Benz | Car Service Centre In Poole, Dorset

www.star-tech.co.uk

 

[RussJ]

Looking at the strut more closely, is there any reason why I shouldn't disconnect the hose from the strut end rather than the pipe end?
Looks like a couple of Torx bolts on the strut so then I wouldn't need to disturb the hose connection, just re-connect to the new strut.

 

[Alps]

I had a similar situation where MOT guy picked up slight misting on one shock, mercedes replaced the pair under "used car warranty". Luckily had a few days left still as "extended Mercedes warranty" wouldn't have covered shocks!