I've sealed mine couple of months ago and epoxy is still going strong.
MB dealer inspected my airmatic with epoxy on there and said everything works as designed.
I am so thankful for those videos and all the help!!!!!!

 

Great. Any idea why the videos are no longer available?

 

Can anyone give instructions on how this is done? How many have tried this?

Is the expoxy just added to the crack or should the paint be removed?

 

If I remember correctly, the gentleman removed the epoxy previously put there by MB with a small chisel. If you have the updates; there will be no sealant present. Then, he scuffed the the metal with coarse sandpaper to give the sealant something to bite into. He used a two part epoxy putty but I don't see why you couldn't use liquid, two part epoxy to really fill in the small gaps. It would be harder to remove but the next step is replacement anyway so it shouldn't really matter.

I have a hard time getting on board with this fix even though MB used a variation of it. Brings to mind a horrible musical parody. "Ridin' in my epoxy suspended Benz.....OH, Crap! I meant lowrider." If you have never experienced Airmatic failure; let me tell you....a '64 Impala with hydraulics has nothing on a W220. Running over painted road lines could possibly do serious damage to the underside of the machine. OK, maybe not that low...but close.

Sam

 

But any idea what happened to the guy?

Did the expoxy fix the leak and did it hold up?

Too bad the video are no longer available.

 

Let's get some things straight here.

1) The epoxy is not the seal for the upper strut. It is a vibration damper to help the narrow neck of the brass valve at the top of the strut avoid cracking and leaking due to vibration.

2) The oldest struts (used in '00 and early '01) did not have the epoxy.

3) Newer struts on new cars did have the epoxy installed at the factory.

4) The epoxy, if present, must be removed to put a new seal in place.

5) If a whole new strut is installed, it will not have the epoxy, but the epoxy should be added to fulfill the vibration damper function - not to seal the strut.

6) Replacing the epoxy without replacing the seal under the epoxy will not fix a leak.

 

THIS IS THE FIX I MEAN:



Hello all,

First, I apologize for possibly "overdoing" it with my contributions, but this happens from posting stuff here as I carry out the stuff and I want to contribute ideas or videos, hot-off-the-press. After this weekend, I will have less time, and back to real work! ;-)

In a previous message, I indicated that I had lost the full video of replacing the mastic from my driver's side, which did NOT have any apparent air leak. I have found the video, and have posted it to youtube (links below), and I have confirmed that once I removed the mastic, there is a leak in the gap of the C-ring, and I have proceeded to epoxy the full circumference of the steel cap.

If of interest, here are the 4 videos I recovered from my mobile, which I had thought lost (there were in the phone memory vs the SD card). The last one is incomplete as the battery did die at that point.

YouTube - step a - removing black mastic - driver side epoxy fix
YouTube - step b - removing hose and brass valve - driver side epoxy fix
YouTube - step c - sanding1 - driver side epoxy fix
YouTube - step d - sanding2 and epoxy - driver side epoxy fix


Skylaw, without wanting to be stubborn, in comparing the W220.175 (2002 S500) upper seal of the front struts with earlier versions, including your previous 2000 S500, it would be beneficial to get the details as to the thickness of the steel cap, the presence or not of an O-rubber ring in the circumference of the original steel caps of previous S-models that did not have mastic, and the design and thickness of the brass valves and its threading into the strut connection hole that experienced metal fatigue.

One can see from the steps a and b in the previous youtube videos that my non-leaking driver side strut did start leaking from the cap once the mastic was removed, with no aparent damage caused from my removal process (using screwdriver and hammer). This is whata leads me to think that the mastic is actually acting as a sealant - again without wanting to be stuborn, just calling it as I see it. Anyway, I could be wrong of whether this was intentional or not.

From dko888's pict of the steel cap from the new fix-kit, we can see that there is an O-ring. From other posts, I think that we can expect to find *no* such O-ring in the original steel cap.

Also, the original and fix-kit design of screwing the brass-valve to the steel strut hole is open to leakage, since this metal-to-metal connection also does not have a rubber washer or O-ring. Again, the brass-valve connection to the strut was originally under the mastic, just enough to seal (my opinion), and not really enough for full-vibration-absorption (especially sideways and upwards). I have taken your advice, however, and in sealing with epoxy the brass-valve connection to the strut (steps 10-12 of other youtube videos), I have added quite a bit of epoxy in an arch around the brass-valve to add considerable structural reinforcement (see picts from previous posts).

Anyway, just a few more thoughts on this. Hope that this information (apologies if it is too much) is useful.

Today I will be filling the bellow with air (will try to do my last videos!), and then testing the car.

Cheers

 

I have no doubt that if a leak develops in the seal, or a crack in the valve neck, the mastic will temporarily delay the onset of the leak. However, cracks will soon show in the mastic, and the leak will occur.

Although the caps' designs did change, there was a rubber seal in all of them - though not necessarily an O-ring (as I recall it was flat). In the oldest style (not having the mastic), fatigue cracks would also form in the metal and cause a leak. I had it happen on my '00, and could plainly see the cracks beginning.

In my OE '05 struts, the mastic reaches just above the bottom of the valve, covering the neck and the bottom of the valve. The mastic is level.

 

Ok, great. Thank you for all the explanations.

Can you show me a picture of mastic on your new struts?

With the special tool, this is a DIY, right?

Do the struts need to be removed to change the cap and seal?

 

Mine look just like the ones with mastic at at Air-matic failed !! - MBWorld.org Forums - except, no cracks. From what I read on the forums, it is a DIY job with the special tool.

 

airmatic epoxy fix documentation



I'm back. The videos have been replaced by a pdf document - 1st doc attached "SUMMARY OF EPOXY FIX..." Hope it is more useful, allowing for quick review, printing, etc, which is more difficult with the videos.

Even though I prefer the Epoxy fix myself, for comparative purposes and as useful documentation, I have also posted two versions of the OFFICIAL WIS documentation relating to the fix-kit replacement procedure.

If you prefer NOT to do the epoxy fix, the FIX-KIT part number from MB is: A 220 320 25 38 for the W220 car without ABC (active body control) and without 4matic.

The fix-kit includes a new upper metal cap that includes an O-ring, and a new c-clip and brass valve, with yellow lubricant. you can see pictures at:
http://www.benzworld.org/forums/w220-s-class/1358307-leaking-front-struts-8.html#post3244659

If you decide to carry out the epoxy fix, you do NOT need the MB fix-kit.

REFILLING THE BELLOWS IS PROBABLY THE MOST IMPORTANT STEP AFTER DEALING WITH THE UPPER-PART OF THE STRUT WITH EITHER EPOXY OR THE FIX-KIT.

NOTE: of particular interest, read about the different alternatives that exist to REFILL the BELLOWS after having carried either the fix-kit or epoxy replacement.

I have received messages from users that have damaged their front struts from improper filling, which then require replacing them entirely. Actually, if you break, tear or perforate your bellow covers, these are sold online, and you can replace any bad bellow covers, without having to replace the whole strut. If you do this, please be sure to post a thread with your procedure and any advice.

Pls read all documentation and understand what and why you are doing stuff - if in doubt, come back, and ask here! It is important to understand that the bellow of the strut (inside the wheel wheel) has a cover with an accordion design with horizontal folds, and must be free of vertical creases or folds to ensure proper function.

If the bellow cover is damaged, this part can also be replaced, as replacement bellow covers are sold from MB and aftermarket. (not covered here).

Even though I inserted warnings in the documents, about being careful, this epoxy fix is very easy for DIY.

Don't be afraid.

Be sure to have read the full procedure, and that you have gathered all the tools and ingredients prior to starting. Also, be sure to be patient in removing, curing and testing the epoxy fix.

Lastly, in terms of tools, be sure NOT to use the one-leg jack that comes with your Benz - it is a VERY dangerous jack to use, especially for long periods, or when getting under the car, getting into the wheel well, etc.

You need to invest in TWO good pneumatic jacks, which should be about $30-$40 each at your local hardware shop, which have wide bases with wheels, and are very steady and reliable. The Epoxy fix also does not require that you remove the wheels.

Go for it, and good luck! Let us know how it went!

Regardless of the fix you decide to carry out as a DIY, I strongly recommend to read all 4 documents below prior to doing anything.

UPDATES: A few users have commented on the need to apply some sort of sealing tape/string for the brass-valve, which will sometimes leak slightly, either in the epoxy fix or the MB fix-kit, given that the brass-valve is a steel-on-steel joint. Have a look at the comments later on in this thread for more feedback and ideas.

 

There is a kit you can buy to fix the leak on top of the air matic shocks. Scraping out the old black epoxy and filling it back in will not fix this. The part that leaks is a half metal and rubber cap under the black epoxy and secured with a metal lock ring. The new kit has all new parts and fixes the leak on top. When down you do not have to fill the top with epoxy. The cap is the part that is leaking. I have done many of these. Good luck

 

Epoxy is a good alternative



Yes, the kit, for about $150-200 per side, parts only, will work. Then you also need to consider getting a special tool (three legs) for $50-100 to push down and remove/replace the undelying plate, etc, etc.

The epoxy fix, at about $5 per side, is much, much easier, since it does not involve removing and replacing the original steel metal cap.

I also recommend, in either solution you decide to carry out, to invest in TWO good pneumatic car jacks, $30-40 each.

The original steel cap is PERFECTLY FINE, and it is impossible to develop any cracks given its thickness. The main problem is simply a design that used black mastic instead of an O-ring, to seal around it.

For this reason, the missing O-ring is NOT required to be fixed, since replacing the black mastic with epoxy fixes the faulty and cracking black mastic. Using a good epoxy (see doc in other post), the original black mastic specs are superceeded.

Whether one uses the fix-kit (a new top-plate with the new O-ring) or leaves the original plate and replaces the old mastic with new epoxy, the idea is to ensure that the strut doesn't leak, and both solutions achieve. this.

You decide how much money and effort to invest/spend.

By the way, the epoxy can always be removed, since it is soft to sanding or drilling, but otherwise provides an excellent seal if left alone. It withstands the heat and pressures for the engine and strut.

I have had this fix on my car for over 18 months, and everything is working perfectly. Pictures below.

In addition to the epoxy, I also spray painted with regular car paint to make it look nicer. I also decided not to reinforce the brass-valve as I indicate as an option in the fix doc attached above.

Contrary to other opinions on this forum, the black mastic's function is to seal the circumference of the upper metal cap on the upper part of the front strut. It is not there to support the brass valve.

The mastic is not there for any other purpose but to seal the upper metal cap - and if you replace it with good epoxy, you're as good as when the car rolled off the assembly line.

 

I appreciate your thorough documentation, and I am very happy that your epoxy solution has worked. I don't oppose an inexpensive solution if it is effective.

However, I stand by what I said in post #9. There can be cracks in the metal - especially when car predates the '02 model year. My '00 had an entirely different design of strut top, and indeed, it flexed and began to crack. The earlier design had stamped and raised concentric circles and a smaller seal. The newer design, which your '02 (and my '05) has, is flat and is made of much thicker metal than my '00 was.

Second, the actual seal is below the circlip, on the opposite side of the plate. The circlip is not the seal - it serves to hold the components together tightly, so that the seal presses against the metal mount tightly. It is when the seal itself, under the circlip, leaks, that problems begin.

The mastic is, according to MB techs who have done many of these repairs, a vibration damper that keeps the narrow neck of the valve from flexing and itself cracking. Some MB repair instructions have not even required replacement of the mastic, and some MB techs don't replace it. If the mastic were the actual seal, such a repair would be worthless. In fact, the older design strut tops/seals (with the stamped concentric circles) did not have the mastic at all when they came from the factory.

Your approach does indeed stop a leak that has occurred in the seal itself - after the leak point, which is the seal ring under (below) the circlip. Your suggestion of roughening of the metal surface to help hold the epoxy in place is a good one, and is likely what allows your solution to work for a decent amount of time.

I am not criticizing your approach - as I said in a different post, it's tough to argue against success. Yours is much less expensive, and it has worked (to date) for you for 18 months. But your theory of the function of the mastic is wrong, as is your assumption that leaks won't occur because of cracks in the metal (at least, of older models - and I saw them in my '00).

Thanks for documenting your effort. Good job!

 

I appreciate your thorough documentation, and I am very happy that your epoxy solution has worked. I don't oppose an inexpensive solution if it is effective.

Thx. How about making this a sticky, allowing fast and easy access to users looking for this very common problem?

However, I stand by what I said in post #9. There can be cracks in the metal - especially when car predates the '02 model year. My '00 had an entirely different design of strut top, and indeed, it flexed and began to crack. The earlier design had stamped and raised concentric circles and a smaller seal. The newer design, which your '02 (and my '05) has, is flat and is made of much thicker metal than my '00 was.

Yes, I can see that if the upper metal cap is thinner, it can suffer from bending and cracking, and would need replacing, and not simply an epoxy refill. Having removed the mastic, it is definitely important for users to visually check the upper metal plate. In my picts, you can see that it is in perfect condition. Pre-'02 owners should let us know the condition of their upper plates.

Second, the actual seal is below the circlip, on the opposite side of the plate. The circlip is not the seal - it serves to hold the components together tightly, so that the seal presses against the metal mount tightly.

Yes, I agree - the circlip (C-clip), is not a seal, it only holds the metal plate in place at the top of the strut.

It is when the seal itself, under the circlip, leaks, that problems begin.

I would add that the upper strut metal plate does NOT have a seal, strictly speaking. It is not a matter of WHEN the metal cap will leak, it ALWAYS leaks. I tested this theory on my driver side strut which had perfect mastic and no leaks - once I removed the mastic, the strut was leaking via the plate. The problem is that no O-ring was called for to seal the original metal cap. This is where I indicate that the mastic is used to seal the strut ABOVE the metal cap - and problems occur when the mastic starts to crack, given the mastic's bad specs.

The mastic is, according to MB techs who have done many of these repairs, a vibration damper that keeps the narrow neck of the valve from flexing and itself cracking.

Skylaw, this is where both of us need to agree to disagree. I hold that the mastic is not there to dampen vibrations for the brass valve. No brass valves have ever cracked, with or withour mastic or similar stuff to "hold" it.

Some MB repair instructions have not even required replacement of the mastic, and some MB techs don't replace it. If the mastic were the actual seal, such a repair would be worthless. In fact, the older design strut tops/seals (with the stamped concentric circles) did not have the mastic at all when they came from the factory.

The fix-kit does not call for replacing the mastic, given that the metal plate is replaced with one that has an O-ring instead.

Summary:
orig.plate + mastic = orig.plate + epoxy = new plate + O.ring

two alternatives, user's choice.

Can't say much about older designs.

Your approach does indeed stop a leak that has occurred in the seal itself - after the leak point, which is the seal ring under (below) the circlip. Your suggestion of roughening of the metal surface to help hold the epoxy in place is a good one, and is likely what allows your solution to work for a decent amount of time.

My approach is simply to replace cracked mastic whose function is to seal an original design which did not include a seal at the metal cap, but above it with the mastic. I am simply replacing a faulty piece of that original design: old mastic = new epoxy.

The fix-kit changes the fundamentals of the orignal design, to include an O-ring with the metal cap, and avoid having to seal above the metal cap. Hence the fix-kit doesn't call for mastic refill.

The end result, in both scenarios = air-tight strut.

I am not criticizing your approach - as I said in a different post, it's tough to argue against success. Yours is much less expensive, and it has worked (to date) for you for 18 months. But your theory of the function of the mastic is wrong, as is your assumption that leaks won't occur because of cracks in the metal (at least, of older models - and I saw them in my '00).

I'll be sure to be back every six month-12 months to this thread, and keep you updated. If something happens sooner, I'll be sure to be back with any late-breaking news - but the epoxy appears to be better than ever, and will probably outlast other parts of the car..... ;-)

Thanks for documenting your effort. Good job!

Thx. It is my way of giving back to the community with solid and easy-to-follow documentation, the sort I would love to have when dealing with a DIY fix.

 

In fact I would like to add this thread to the W220 S-Class Owners Start Here sticky (it's called the Encyclopedia on BenzWorld and MBCA) - but I have to figure out how to add another post in the middle of the two lengthy ones on BW - they're both at their character limits. But you can look for it!

 

Hello Skylaw, good to hear that this post will be a sticky to help future community members with such a common problem.
BTW, I have always posted the official MB fix-kit procedure side-by-side with my own epoxy fix. I have edited my post above to make this more obvious.

With regards to the other two links from the encyclopedia, a few comments:

Airmatic Strut Kit Install - MBWorld.org Forums
-- the fix-kit description is rather general, no pictures, etc, and a very weak procedure to refill the bellows - which is very important to do properly. In fact, I am thinking of beefing up this section in my own documentation.

Airmatic Questions!! - MBWorld.org Forums
-- a few key ideas that need fixing:
1) "Cracks forming in the mastic at the top of the front struts, indicating that a seal beneath the mastic may be leaking"
--cracking mastic is simply that, "cracking mastic", and a loss of the only seal that originally comes with the car. Cracking mastic does not mean that the upper cap has lost its seal and is starting to leak. The original upper metal cap has no seal, and will always leak - hence the mastic.
2) "opening the door does not cause the release".
--Actually, opening the door can cause the car to raise, even if the engine is off, and no key in the ignition. The document listed above, "W220 airmatic documentation" explains a lot of the functioning of the airmatic system, but here are a few key points:

An AIRmatic central reservoir for compressed air also enables the
vehicle level to be controlled when the engine is not running. In
addition the adjustment of the vehicle level is decoupled from the air
compressor.

Wake-up function (operating period approx. 1 minute)
The AIRmatic with ADS control module is "woken up" using the
remote control, door contact switches or trunk illumination switch in
order to check the current vehicle level for critical conditions (level
too low) and if necessary to raise the vehicle or lower it when
unloading.

etc, etc.


Another observation worth mentioning is the need to summarize all of the posts into one KEY document or thread or post - like a wiki. This avoids having to read tons and tons of posts that then require the user to use whatever experience or judgment to distill and decide how to move forward. This sort of editing would increase the value of your forum 1,000,000 times. at least.

 

It might, but it would also tremendously increase the amount of time that I must devote to the forums. I don't have an infinite amount of time (or the inclination) to do that. To do it as you suggest would require a great deal of additional writing to knit the various members' contributions together. The document as it stands took considerable time - and no one had done it in the 8 years the W220 has existed (counting its 1999 European introduction).

From my standpoint, it's one more suggestion for how I can devote more of my time for unpaid work, so others won't have to read several threads, and think. Not a very attractive proposition, given the time I have already spent.

Except for the time required not working for me, it's a good suggestion. Perhaps you'd like to take it on.

 

we can all do the work.




Okay, I understand. I can only really devote time to document the problems that I experience, and give that back to the community.

How about having functionality on the forum that allows the readers/users to rate the individual comments - that could, over time help filter by relevance/rating. In essence, the community makes this sort or filtering among tons of messages easy.

Another thing would be developing some sort of classification scheme (searchable) similar to tags, that the authors or moderators can tick on, allowing to quickly find similar stuff. At present I think the site search could work a little better. I think that personalized miini-google can also be activated within the site only.

 

Sealing the top with mastic and RR with MB seal is not the same as roble said above. Yes his mastic can seal the top but his seal still leak below. Engineer will not be that stupid to put a movable seal there if a capped top can perform the same. A capped strut will created an extra chamber. How does this will affect or compromised the performance ? This is your choice.

 

Look, if we are going to start planting doubt into a DIY's mind, then, believe me, the DIY of the upper seal is not worth it. Just tell the DIY to fork out the $500 for the parts (fix-kits) and 1-2 hours at the MB dealer and get the new caps placed by someone else.

Be sure to ask the shop for the old parts - the old plates and brass valves could come in handy in the future.

daisound, with all due respect I noticed that in another thread, the user with the lose bellows didn't seem to get any advice as to how to refill his bellows - and instead is getting potentiall wrong advice to replace the front struts! OUCH $$! This sort of stuff should be avoided with more specialized moderators for each system on the W220 (I volunteer!), and don't know if the user "lyoooha" ended up changing potentially perfect good front struts!
http://www.benzworld.org/forums/w220-s-class/1524618-compressed-air-leaking-bottom-my-front.html

By the way, if your airmatic struts DO need replacing, from bad, broken bellows, excessive rust, etc, Arnott is a great alternative $399 per front side! (btw, if rebuilt struts are $399, how can MB charge us $150-200 for the fix-kit = 1 c.clip + 1 new plate + 1 brass valve per side!!!!)
More info at:
http://www.arnottindustries.com/part_MERCEDES-BENZ_Air_Suspension_Parts_yid18_pid126.html

It is important that when dishing out advice, that it be correct. It is important to understand the components of the system, understanding the "why is this here" and "what is the function", in order to then find "how do I fix it". I am a software engineer, and don't profess to be a mechanic, but I have analyzed the sh-t out of the front struts before doing my DIY, and can hold my own with any mechanic talking about the W220 front struts - believe me.

Yes, the new plate with the O-ring is a different fix than the old plate plus epoxy, I agree, however the result is the same.

You are incorrect in stating that an extra chamber is created above the metal cap, since the epoxy is attached directly to the metal cap and side walls of strut (in the "valley"). The performance is exactly the same, and 18 months later my car, always riding in Sport I position on city streets, proves it. My car doesn't lose ANY air, even after being parked in the garage during 3-4 weeks in bad snow weather.
picts of my upper-strut epoxy fix are at:
http://www.benzworld.org/forums/w220-s-class/1467695-airmatic-strut-epoxy-fix-2.html#post4256210

Why wouldn't an MB shop consider epoxy fix? a few ideas:

- can charge $150-200 for a simple metal cap with an O-ring, which probably costs only $3 to manufacture.
- the epoxy fix requires curing time, and is considered "wet" work (working with malleable stuff at the shop) requiring time at the shop
- the look is not "professional"

Hey, you're right, two alternatives = choice for the user.

In the mean time, I've used the $500 towards the purchase of a Star Diagnostic System, AND I still have a solid airmatic fix.

 

"Arnott is a great alternative $399 per front side! "

Now THAT is great news !

I am considering a YM 2000 S class purchase and reading all the info on the AirMatic is a bit frightening, but knowing there are full replacements that can be had for > $800 puts a reasonable "cap" on a worst case scenario to what looks like the Achille's heal on the Class S .

 

The air struts would have to be changed in pairs, both front or both back. If changing the front struts, you may consider looking at the back ones as well - and perhaps replace all 4 at once.

I noticed that my struts are getting a little rust on the lower metal housing, especially around the damping valve unit (smaller cylinders attached to strut lower core)... I will be painting these this summer, but may be good to replace in a 3-4 years...

Here are pictures of the left front and left back struts. The back strut seems to have worse rust from the canadian winters.

 

roble
If the sealed top same as sealed upper piston then the new bilstin strut can be modified with a capped top. Why arnott did not modified that way for life time warranty ? Instead they just improved the upper seals. I replaced the old seals with a new one and it only cost $262 DIY for both sides. This put my car back to the original design. I agreed with you that $10 can fix the problem but you are compromised the performance. When air goes into the top of the strut, which is between the upper and lower seals, the original design will extend the piston of the strut and the air housing, but in your case, it will only extend the air housing because the piston upper seal leaks.

 

What are we discussing here, exactly?

roble
If the sealed top same as sealed upper piston then the new bilstin strut can be modified with a capped top. Why arnott did not modified that way for life time warranty ? Instead they just improved the upper seals.

There is a difference of understanding here. I would suggest that you explain a little better, since you are indicating that a sealed top is not the same as a sealed upper piston. What is, exactly, a "sealed upper piston"? What upper seals do you indicate that Arnott has fixed, and how, exactly?

I replaced the old seals with a new one and it only cost $262 DIY for both sides.

What exactly did your fix of "replacing" the old seals include? Do you have pictures? Did you need to replace the metal cap, under the black mastic?

This put my car back to the original design. I agreed with you that $10 can fix the problem but you are compromised the performance.
When air goes into the top of the strut, which is between the upper and lower seals, the original design will extend the piston of the strut and the air housing, but in your case, it will only extend the air housing because the piston upper seal leaks.

It appears to me that you are talking about internal issues and seals, not simply fixing the leak by removing and replacing the black mastic with epoxy, or using the fix-kit, by replacing the upper metal plate without an O-ring with the new one that has an O-ring.

If you don't approve of the epoxy fix, do you approve of the fix-kit? In essence the idea is to seal the upper metal cap, with an O-ring or my case, epoxy. It's as simple as that. No compromise in performance exists.

The convenience of the fix-kit and new plate with an O-ring is that it is easy to open and re-close, whereas the epoxy would need a new re-application. This is a non-issue, since the struts do not require regular maintenance, and staying sealed "for ever" is the norm, hence the epoxy fix if perfectly fine as a permanent seal.

The Epoxy duplicates exactly the same function as the fix-kit O-ring: seal the upper metal cap.

I don't understand what you are referring to in terms of different performance, and "extending the piston strut, air housing, etc." - I believe that you are talking of a different seal problem.

I have included below a diagram of the internal workings, with a brief explanation, and some pictures, that would facilitate your explanation of exactly what seals you are referring to, and what the Epoxy fix is exactly about. All this is included in the documents I posted previously, but just in case this wasn't "noticed".
(Click on image to see a larger version).

Thanks in advance for you information.

 

I recently applied the epoxy fix to my front struts using the PDF guide posted in this thread and thought I would share my experiences.

Firstly, the epoxy fix works and works well. Mine were leaking badly, and there are absolutely no signs of any leaks now. And I have been checking!

Secondly, I encourage anybody with leaking struts to apply this fix. I investigated doing it "properly" using the repair kits, and frankly I thought the kits were an absolute rip off ($550ea here in Australia) and the work required to fit them looked tedious and difficult, and required specialist tools which also needed to be purchased. As robledoch stated, I would rate this epoxy fix as EASY, even for a novice DIYer - thanks to the excellent guide that robledoch has put together.

Thirdly, just to set as ease some fears some might have about tackling this job. I raced ahead over enthusiastically and missed steps and made mistakes and still ended up with a very successful result. The commends in this thread and the steps given for supporting/lowering/refilling/raising the vehicle - whilst being absolutely correct - make the system sound tedious and fragile. The first time I tried this fix I simply undid the airlines to the struts and the car sank to the ground without any supports at all. I would not suggest that anybody else do it like this, but my point is that even if you do it all wrong, the system and its components are quite robust and you are unlikely to affect the result or cause damage to your car. Having a pump fail on me earlier on and having played with the Airmatic system a fair bit since, it is my belief that the issue of setting ride heights etc. following these kind of repairs (as speculated about in some other threads) is a load of nonsense. There are height sensors at the front wheels (1 at the rear) - the car rises until the sensors reach a level stored in the Airmatic ECU. Then it stops rising. It is as simple as that. So unless you start fiddling with those height sensors or the ECU, ride height "setting" issues are irrelevant to this procedure – you are not going to break anything!

Fourthly, as robledoch stated clearly - READ THE INSTRUCTIONS COMPLETELY before you begin. The first time I did this I failed to remove the valves and the air continued to leak around them. One advantage I have in having made this mistake is that I can tell you from experience that it is relatively easy to remove all the epoxy if you think you have stuffed it all up and want to start again or if you decide that you do want to install the proper repair kits later on. Applying this fix DOES NOT stop you from installing the proper repair kits later on if you wish. I removed the epoxy fix quite easily with a drill and a chisel.

Finally, some variations that might make this fix easier or more effective for some. I bought some concrete blocks from a hardware store for $1 each to support the car on my second attempt – safer than jacks and they exactly the right height to keep the car at a normal ride level. I did not clean my struts with a wire brush drill attachment as suggested in the guide. If you have this tool it will make the job easier, but it is not the only way to effectively prepare the surface. I used a chisel to scrape away all the paint/resin and roughen up the surface (anything sharp will do). I then used some sandpaper to make sure the surface was absolutely back to bare metal. Finally, I used some 3M wax and grease remover to clean the surface prior to applying the epoxy. I used the Permatex multi-metal sticks as suggested in the guide - I used 1 stick for each strut. I let this set overnight before refilling the struts. One thing that is a little bit unclear in the guide is the reinsertion of the valves - after several attempts and several different methods I could not get my valves to seal properly. The method that worked was to apply a few layers of gasfitters thread tape around the valve thread before screwing it into the strut. This sealed the valve immediately. I recommend that everybody apply a similar thread tape to the valve upon reinsertion. Although I intend on adding some epoxy around the valve to give it a neat appearance, do not rely on placing epoxy around the valve to seal a leaking valve thread - it didn't work for me and it is easy enough to put some thread tape on it and seal it properly.

The epoxy fix has been applied to my car for several months now - no leaks - no reduction in performance (in my opinion daisound's comments regarding compromised performance make him either practically unfamiliar with this system or an idiot). I don't feel this fix is "superior" to the proper repair kit, but it is certainly not inferior. I guess the determining factors really are whether or not you have money to burn, and whether or not you can be persuaded to get in and give it a go.

I hope my comments will make a few more of you feel comfortable about tackling this fix – it really is too easy. You CAN do it, and it WILL work.

And robledoch, you are an absolute legend for putting all this together – I personally owe you a thank you for the thousands of dollars you have saved me. Thank you and much appreciated!

 

One thing that is a little bit unclear in the guide is the reinsertion of the valves - after several attempts and several different methods I could not get my valves to seal properly. The method that worked was to apply a few layers of gasfitters thread tape around the valve thread before screwing it into the strut. This sealed the valve immediately. I recommend that everybody apply a similar thread tape to the valve upon reinsertion. Although I intend on adding some epoxy around the valve to give it a neat appearance, do not rely on placing epoxy around the valve to seal a leaking valve thread - it didn't work for me and it is easy enough to put some thread tape on it and seal it properly.

Hello hcsodh, yes, the brass valve sometimes leaks at the point of entry into it's insertion point of the strut (no O-ring design either), and your solution of using gasfitters thread tape sounds like a good long-term solution. I also agree that using epoxy is more difficult to seal the brass valve since all the brass valve surface is very smooth, making it difficult for the epoxy to adhere to properly (and I don're recommend sanding the brass valve at all).

The epoxy fix has been applied to my car for several months now - no leaks - no reduction in performance (in my opinion daisound's comments regarding compromised performance make him either practically unfamiliar with this system or an idiot). I don't feel this fix is "superior" to the proper repair kit, but it is certainly not inferior. I guess the determining factors really are whether or not you have money to burn, and whether or not you can be persuaded to get in and give it a go.

Good to know things are working well. Be sure to give us an update every 12 months or so.

I hope my comments will make a few more of you feel comfortable about tackling this fix – it really is too easy. You CAN do it, and it WILL work.

Yes, it is important to encourage DIYers. One of my surprises to the epoxy fix is the consistent negativity communicated by a few members, which I can only assume is due to insufficient information and knowledge of the original design and function, and how the epoxy fix restores the original design by replacing cracked epoxy.

And robledoch, you are an absolute legend for putting all this together – I personally owe you a thank you for the thousands of dollars you have saved me. Thank you and much appreciated!

You're welcome and Thanks for your write-up! I figured that such a common problem was missing an easy-to-follow solution, which prompted me to initially do videos, followed by the PDF document. This epoxy fix is not only cost-effective - especially if the owner can't fall-back on a warranty with MB - it is also very easy. I am very happy to know that you have learned new things about your W220, with full control, and saved money along the way!

 

The engineer designed a seal instead of a air tight cap at the top may intend to have a relief there to maintain a safety valve at the top in case air pressure needs to be released or suck in when the wheel is off ground. This may be a pressure protection for the lower air seal. In other words they rather let air in/out from the top than damaged the lower seal. It is your choice to change a OEM design for your own saving. I always do not believe layman like you will mod. a car better than OEM design. I deal with machine product in my life. It is much cheaper to build a strut with air tight seal metal cap than a seal cap like the OEM. Do whatever you like with your car or just taken the air strut out to replace with spring just like other threads and I guaranteed you it will be cheaper to operate. If you ask me why the OEM designed seal is better than your air tight seal, you may ask a Bilstein strut engineer. so I am not an idiot, but just smart MBA in reasoning and I will not make modification because of $250 DIY seal kit from MB. Even the newer S550 or any current S class, Bilstein still use a valve seal but not an air tight cap. The seal problem has been costing MB much higher warranty service expenses in last 10 years. They have MBA's smart guys there to run the books. This will be modified if it can be done. But if you think that $250 is so justified for the change, it just serve you right.:rocketwhore::big laugh:

 

Still waiting for specifics

The engineer designed a seal instead of a air tight cap at the top may intend to have a relief there to maintain a safety valve at the top in case air pressure needs to be released or suck in when the wheel is off ground. This may be a pressure protection for the lower air seal. In other words they rather let air in/out from the top than damaged the lower seal. It is your choice to change a OEM design for your own saving. I always do not believe layman like you will mod. a car better than OEM design. I deal with machine product in my life. It is much cheaper to build a strut with air tight seal metal cap than a seal cap like the OEM. Do whatever you like with your car or just taken the air strut out to replace with spring just like other threads and I guaranteed you it will be cheaper to operate. If you ask me why the OEM designed seal is better than your air tight seal, you may ask a Bilstein strut engineer. so I am not an idiot, but just smart MBA in reasoning and I will not make modification because of $250 DIY seal kit from MB. Even the newer S550 or any current S class, Bilstein still use a valve seal but not an air tight cap. The seal problem has been costing MB much higher warranty service expenses in last 10 years. They have MBA's smart guys there to run the books. This will be modified if it can be done. But if you think that $250 is so justified for the change, it just serve you right.

Daisound, sorry, but you do not appear to understand the mechanics of the upper seal, and the effect of REPLACING the original black mastic with new epoxy.

No one is questioning your level of formal education, and your MBA degree.

I have gone to great lengths in previous posts to ask you questions, which you have ignored, (and you are free to do so!) but it is not helpful to others to start posting incorrect statements that are not backed up with diagrams, pictures, etc.. Feel free to document your reasoning, for a proper peer-review! We may be layman mechanics, but we are willing to give you an audience.

 

Thanks for your guide roble.

I am stuck at the brass valve removal. it's just not turning. I am trying to turn it counter-clockwise to get it removed. I am grabbing it from the top closer to where the hose was hooked into.

Any info about this would be appreciated.

Thanks.

 

removing brass valve



You have several options here. MB sells a special device that fits over the brass valve, and into the two U-"slots" at the top (wider-end of the valve), where the air hose attaches.

You can also try using groove-lock pliers (as in the pictures below), by getting the teeth of the pliers to pull on the U-"slots" of the brass valve, and ensuring that you are turning counter-clockwise for removal. Be sure that the pliers have arches, that properly fit the circumference of the brass valve, to ensure a good grip. Avoid using straight pliers or pliers too small for the valve.

NEVER squeeze the brass valves in the mid-portion or the lower end (smaller circumference), which fits into the strut.

Pliers with metal teeth may scratch the smooth surface of the brass valve, but its function will not be affected (it will simply look scratched).

To avoid scratches, you can also use pliers with rubber teeth, which may not grip as easily as those without the rubber, and may not free-up a tightly screwed-on valve.

When reattaching the brass-valve after the epoxy has cured, be sure not to over-tighten. And to avoid potential leaks at the brass-valve entry-point, as suggested by "hcsodh", you can try using thread tape prior to screwing in the valve.

If you decide to purchase the official fix-kit from MB, replacement brass-valves are included, which have some red wax applied to the brass-valve thread to ensure a proper seal, even though original brass-valve design remains the same.

(pictures below of the brass valve, originally by "dko888" member)

 

roble
I see the diagram you put forward for the forum to understand the internal construction of the strut. But that does not really tell us any design philosophy behind each and every materials the engineers used. You and the few try to modified the design and justified yourselves for the saving of US$250 and telling the forum it is the same as what the original engineers should be used to take care of the problem which has been the most serious S class warranty cost for MB in last 10 years. With my common sense judgment, I totally disagree with your modification. I do not have the knowledge to discredit or proof you are incorrect, but neither do you proof you are correct. So the diagram is meaningless, unless you are the qualified designer for the product. We will have no end to this discussion, let go of it and the forum will decide what they want. I just put out my opinion, so they can make their own.:topic:

 

Your choice

roble
With my common sense judgment, I totally disagree with your modification. I do not have the knowledge to discredit or proof you are incorrect, but neither do you proof you are correct.

Isn't the fact that our airmatic systems work perfectly (mine for over 20 months now) proof enough? even though I explain the logic of the fix in detail anyway?

You are entitled to your opinion, no matter how wrong ro right it is. And what is very confusing to me is that you are taking a crap on this thread for no apparent reason. You obviously have had bad experiences as a DIYer that fails to understand the workings of the machine you are trying to fix.

If we feel like replacing the epoxy, or using bubble gum to seal the strut, then that is our problem. If you notice, I have posted the official metal-cap replacement procedure as well - and leave it up to the DIYer to decide on which procedure to use.

--epoxy replacement = less $$ and easier

--upper metal cap replacment = more $$ and requires replacing metal cap with special tool.

Have a great day!:beerchugr:


P.S. daisoun, how did your own upper seal fix end up?

http://www.benzworld.org/forums/w220-s-class/1358307-leaking-front-struts-6.html#post3160435

http://www.benzworld.org/forums/w220-s-class/1358307-leaking-front-struts-6.html#post3161649

 

roble
Another smart move made by Arnnott, they modified/reman the strut with the MB seal instead of your method. They could save money just like you did with the core taken apart. Instead they use the MB seal. Why? I think these guys are better qualified than you in the strut business. They also purchase another air bag for the lower seal and offer life time warranty for the strut. It seems to me they are following my thought of reasoning. The MB replacement seal is more dependable and reliable for life time warranty. So the logic tells me that if I RR the MB seal, I could offer life time warranty for myself as long as the lower seal holds up.

 

Daisound, first, thanks for your enthusiasm, since I can only applaud your effort at communicating.

I definitely agree that the reman struts from Arnott at under $400 each, with a proper upper metal cap and O-seal, and new inner "bellows" are an excellent replacement option for the whole strut.

Now, following this reasoning, as a fellow MBA-er, let's look at the numbers. Don't you believe it is is better to save money up-front by doing the epoxy fix, and if required later on, replace the whole strut at $400 each?

The repair kit form MB, at about $200-300 per side, is clearly overpriced, since it only includes changing the upper metal cap (and perhaps the brass valve).

Given the alternatives, and related prices, the MB fix-kit is not a good option, both mechanically and cost-wise.

Now, if you insist, hey, it's your money and your car!

See ya
:beerchugr:

 

unminkug
Find yourself a socket slightly bigger than the brass valve. Grab a nail and cut of its head. The nail should have a shaft slightly smaller than the notch of the brass valve. Make it like a U shape and stuck inside the socket, so you have a home made socket which will slide over the brass valve notches and turn it loose or tight with a torque wrench. You have to experiment the size of the nail to make this work. Sorry, I forgot the exact size of the socket and the nail. That will save you lots of $ and install the valve in the same shape as pro with no scratches. Channel piers will scratched the valve.

 

The last time I RR the seal is $263 for both sides. I hate to rework a problem if I can offer myself a life time warranty. The new seal work very good and the suspension system just comes alive as the car was new. I did not replace any relay, fuse or pump or valve block. Every component rocks. When I first get the low pressure warning, I replaced the seals. That save me the trouble of any other system damages due to the poor original seals. When you replace your tire and have your front wheel lift above ground, the sleeve disconnected from the bottom of the strut, that is the sign of bad seals at the top. Mechanically, the new MB seals are good and dependable. your epoxy has only one good point, inexpensive but unreliable. MB 's old struts designed with 2 seals system per your theory, one is the metal cap seal, second is the epoxy. The RR new design is only one system, the NEW seals. Obviously, the new seal is adequate and the epoxy is not dependable. But Skylaw keep his theory that the epoxy is not for sealing, just for support of the valve. I cannot support either of you guys theory, because I have no idea of the original design philosophy. But I am going for the bottom line, I believed in the new Mod. from the engineer.

 

Leaking faucets

Here goes, a few more explanations:

Mechanically, the new MB seals are good and dependable. your epoxy has only one good point, inexpensive but unreliable.

MB seals depend on an O-ring made of rubber -which deteriorates with temp fluctuations, both ambient (winter-summer) and engine temps (on-off). The O-ring fix is more suceptible to problems than the epoxy which is specifically made for high pressures, temperatures, etc. Epoxy is much more dependable than rubber O-rings. In the event of having to replace, epoxy is easy to remove, and replace. The O-ring would need a new kit (more $$).

But Skylaw keep his theory that the epoxy is not for sealing, just for support of the valve.

Skylaw has gone on record:
http://www.benzworld.org/forums/w220-s-class/1358307-leaking-front-struts-11.html#post4252983

If it works, it is hard to argue with success. Thank you for the follow-up.

I have no idea of the original design philosophy.

This is important.

But I am going for the bottom line, I believed in the new Mod. from the engineer.

Just bear in mind that the original engineers designed a crappy seal-system from the start, by choosing incorrect materials (brittle black mastic), be weary of placing too much faith in them in designing the best solution.

In my opinion, the epoxy replacement is much better that the O-ring in terms of durability in temp and presure conditions.

Futhermore, the epoxy replacement would be more expensive for them to apply given the wait times for curing.

With the MB-fix, they are charging big bucks for a piece of metal, and the replacement doesn't require much wait time at the garage. The new MB kit is actually better for them in terms of labour costs, both with or without warranty.

Do you really believe that a rubber O-ring will outlast an epoxy seal, in absolute terms? The O-ring design is the same as that used in your home faucets. Have you had any leaking faucets lately?

Cheers
:beerchugr: