Go for the arnott if you can do labor yourself

 

I would complain - politely but firmly and in detail - to MBUSA (in addition to the dealer). Ask what they are going to do about the problem.

 

That was my initial thought wallyp.

I have a contact high up in Atlanta to whom I have already sent an email. The dealer had been good to me and is really caught in the middle by this lousy part. Ultimately I took the risk of buying an out of warranty cash car with an out of warranty part. It worked for 35k miles and 2.5 yrs. Now it's a decision between Arnott and another Benz "improvement." My wallet and every shred of common sense in my body are telling me Arnott ?

 

Hi,

With my knowledge of these ABC systems, and Hydraulics in general, I find that to be an incredibly short life for an ABC Strut, especially bearing in mind the Pot Holes all over our UK Roads :frown

I can think of 3 possible scenarios here.........

1) The strut wasn't built right in the first place, i.e. it's "Assembler" caught a Seal and slightly damaged it during the building process, or just plain missed seeing a defective part during assembly.

2) The installer did not excercise thorough cleanliness when installing it, and a small bit of swarf /grit got into an opened Hydraulic Line and this has subsequently damaged the strut.

3) Mis Diagnosis........... Are you absolutely positive it is the strut ?? Sagging can be caused by an Internal Leak Off inside the Valve Block, or even a Small External Leak such as a pipe or joint weeping.

BTW, in the USA I'd go for Arnott every time, sadly in UK the carriage charges price them above MB Dealers

HTH,

Cheers Dave

 

I agree with your assessment Dave 35k miles is ridiculously low. I also came up with the same three scenarios as you and have eliminated the latter two. My dealer's shop foreman is a Master Guild tech...one of a literal handful in the USA who got an all-expenses-paid trip to Germany to train with Benz engineers and at the factory. They have a "fix it right the first time" rate exceeding 90% and I have never once felt like they were trying to deceive me. I nevertheless questioned the front valve block issue today over the phone. My service advisor went out and asked the technician working on my car (rear main seal ). Apparently if the front valve block were the issue, there would be some code STAR DAS returns, and they were not getting that, and so the next thing would be the strut, which is what they diagnosed.

Assuming I swap in the Arnott, is a full CHF 11S flush necessary given my fluid is brand new from the rear valve block in February? Would a top-off post replacement, a Rodeo, and then a new 3micron filter suffice? I have done the full flush before, but would rather not unduly stress the other components with the Rodeo revolutions required for a full flush if not necessary. I will as our Master Guild tech his opinion...our MBCA Tech Session happens to be this Saturday :smile

 

Dave,

Perhaps you should set up shop to rebuild (at least the Airmatic) struts...

 

With the part number ending in 80 that means it is a Mercedes rebuilt part. I am not sure brand new ones are even available anymore.

ABC problems have sliced through a lot of local owner wallets near me. The roads are atrocious and the fluid is under maintained by the owners.

 

Noodles. This is pushing me even farther into the Arnott court. I can replace an Arnott three times for what one of these Benz replacements costs parts alone.

 

Hi,

Firstly can anyone on here recommend a good Indie local to this guy, or do you know one, preferably a guy who has done a few Valve Block rebuilds and knows ABC well.

Get a second opinion pleeeeeease.

OK, from what MB have now said, alarm bells are ringing in my head ...........


Here's why............

There is no way on Gods Earth ABC has both Front Struts plumbed together at or before the Valves :eek

Think about it, it can only be Active Body Control, i.e. each corner can react and adjust independently from the other, it would not be able to counteract pitch and yaw if two struts shared a Valve, Pipe or a VB Passage before the Pump Pressure fluid flow .............

These Front and Rear Valve Blocks each contain one valve for Left and one for Right, and if you follow your Pipes back to the VB you will be able to see that they enter separate Valve Apertures.
Hence, if one Valve is leaking off the car will sag on one corner.

Finally, think of it this way, you are about to spend £1000 ish on a new strut.
A Valve block rebuild kit is approx £40
Your Replacement Strut has done very low mileage.

I'm not saying it definitely isn't the Strut, but given all the facts, I'd be suspecting VB every time, and cost versus your cars new part history, I'd go for the VB first :wink

If Mercedes fit the new Strut and your car does the same thing, will they remove it and re imburse you the costs involved..........Nah !!

I foresee a phone call halfway through the job, along the lines of "Good afternoon sir, we have discovered that your car needs extra work above our original quote" :eek

BTW, my customers CL600 isn't twitchy, it's movement is very slow and rhythmic and is definitely a Valve issue.

My point there was that his car also drops over a period on just one corner due to a VB fault.
ABC VB's have a known and well reported fault that the O rings wear out and they leak off internally, especially caused by not changing the Fluid / Filter regularly :wink

Also, any Hydraulics expert will tell you, it is a fairly regular occurrence / risk that a Valve will give problems after any work has been carried out that involves opening up the system, my earlier comments about cleanliness apply here, and only help to reduce that risk.

However much the Strut fitter cleaned around the Line Connection, there is also a good possibility that the previous Strut failing could have left a small amount of debris in the line, and it's first port of call will be the Valve which controls it :wink

I do hope I am wrong, but experience tells me I'm not far from the truth here :wink

HTH,

Cheers Dave

 

If it is the valve block, would it be a waste at this juncture to try a flush/filter change in an effort to dislodge debris from the recent ABC repair procedures? Thanks

 

I agree with Dave - what you are being told makes no sense. Either what we have here is a failure to communicate, or a serious lack of knowledge by the shop.

 

Are you able to rebuild your valve block yourself ? If so that's the least cost option

If you can't rebuild the valve block yourself, but you can change a strut yourself , I would get the arnott strut . it's covered by a lifetime warranty so you can be assured you'll never need to pay to replace it again

If it turns out the car still sags in that corner you can do two things
1. Ask this shop for a refund of their faulty diagnostic charge
2. Sell the mb strut (which was in fact still good ) on eBay

This will recoup most of the cost of the arnott strut

 

While I have more than enough mechanical chops to tackle a valve block swap, executing the repair without something leaking at the end would be a concern. This is ~2700psi after all.

There is no way I would EVER buy a Benz strut again if it is actually the strut. I am definitely going Arnott, even when it is time for the rears. For a valve block, I would not mind getting the Benz part. Money is not the issue here...I have a liberal budget for this, my favorite feature of any car... ever. It is the notion of paying for something twice that I should really only have to pay for once that is sticking in my craw.

 

Hi,

OK fair play to you, but I think you would probably be more than capable of doing the job :wink
Anyway, if the guy is giving money back for core, he sounds like a fair Professional to me :smile

Compared to things like Mercedes and ZF 6 and 7 speed Auto Gearbox Valve Chests, (which I do a lot of), these little buggers are real simple :grin

Anyway, I'd put the new filter in at the "OK it's done a few hundred miles now and all is well" stage :wink

I only Rodeo if I really have to, wouldn't do it in your case, simply drive and keep an eye on the level, ABC in good order will bleed itself before it has left the workshop :laugh

You are sooooo correct, I love the high end Mercs for all their Technology, and if you think the Autel is good, try playing with SDS :grin

Do not attempt a Calibration EVER, unless there is a real need for it, as the systems get older, and parts wear a little, it really is a guessing game, took me 5 hours to get an old CL500 right, because someone had attempted it using "Factory" specs, and then the ABC Computer had locked out with "Calibration Unsuccessful" :frown

Good luck, and please let us know the outcome :wink

Cheers Dave

 

Put the rebuilt unit in last nite. No sagging this morning, though it seems front passenger was a bit high and promptly "lowered" itself upon backing out of garage. I will continue to monitor and may end up doing the level calibration with the MaxiDAS (I know dealership does this and Rodeo almost every time they service ABC). I skipped the Rodeo and will just replace 3micron filter after 2-3 week of driving as suggested. I also asked the gentleman taking my core to let me know what he finds when he rebuilds it (i.e. condition of o-rings, debris, etc.). Is it normal for the system to seem more "responsive" or "alert" to control body motion after a valve block job? Perhaps it is my imagination, but the car feels even better than it normally does (I have long argued that even worn out ABC is better than brand-new "dumb" struts). The car rides like a fortress!

Side note...both front struts had minor oily residue from base of strut where little hex screw locks strut to lower "wishbone" extending up about 1.5" (4cm) around entire circumference of tube. Neither was hemorrhaging visibly or otherwise dripping, and I have never added fluid in between services. Were it just the left strut, I would have started to believe the dealership's story, but both struts have the same condition. At this time I will assume benign and just monitor condition. If I understand how these struts work, the "business" end is the hydraulic "servomotor" at the top anyways, correct?

Thanks again for all the help!

 

Hi,

Glad you got it sorted :smile

Don't worry no oil can get out at the bottom of each strut, they are solid metal at the bottom :wink

If a decent Technician has had those Grub Screws out before they will, like me put a bit of oil / grease on them so they come apart easily in the future, I expect that is what you are seeing :wink

Yes, car will feel better after a VB is Rebuilt.

Now you can ring that "Highly Trained Mercedes Master Muppet" :grin , and tell him his Diagnostic Skill and Knowledge of ABC needs a lot more work :laugh :laugh :laugh :yelrotflmao: :yelrotflmao: :yelrotflmao:

I'd run the car for at least a week / 200 miles before doing anything about that slightly high side, and remember, if the car is on level ground and idling and sitting at the correct height, then that's just fine :wink

If not, the best thing on an older cars system is to "tweek" the Link Rod between Upper Wishbone and Height Sensor slightly shorter / longer as long as this doesn't mean the Sensor Voltages go under / over tolerance ............

Dave's "ABC Calibration 101" is DON'T DO IT , unless you have no other option

HTH,

Cheers Dave

 

Well, after hundreds of miles of the best ABC performance I have had in recent memory, I swapped in a new 3 micron filter. Because I am a geek, I had to cut the old one (from February when dealer did rear valve block) open to see how dirty it had become. :nerd

 

Wow that filter is just from February ? What color is your abc fluid ?

 

Green...light green. Actually the rebuilder, to whom I need to give a shout-out...name is Sebastian and eBay store is "bavarian_motor_works"...said my fluid was the cleanest he had seen in a long time of parting out ABC cars. The 3 micron is an excellent filter, perhaps singlehandedly responsible for extending the lives of ABC systems beyond the 60-80k miles one typically gets with a first-gen system without a rebuild. The nastiness you see inside my old filter is just the result of it doing its job!

 

Well, the valve block rebuilder ripped mine apart today and provided photos. Sure enough, it needed a rebuild!

The red circle surrounds the offending o-ring, which he said was shrunken/receding. He also noted an o-ring elsewhere on one of the "big" solenoids that had a flat spot. No wonder the car rides better than ever! I made sure to let the dealer know all of this and provide photos.

Thanks all again for your help and mucho dinero left right where it needs to be (in my pocket )

 

Apologies if you already listed it but how much Does he charge to rebuild valve block ?

 

Hi,

$500, with a $100 refund for the old VB

Yep, those seals are awful, that damage was caused by debris from the old strut :wink

3 micron filters and a magnet do make a big difference, as does regular fluid changes using the MB Method which involves Rodeo at the same time, as that is the only way to get a high percentage of the old fluid out :wink

Cheers Dave