mbenzagain

I have a 2000 S430. While driving home a couple days ago, the "Stop, Airmatic too low" warning message came on. I pulled over, turned off the car, restarted it a short while later and it seemed fine. I made it home without the warning coming back on. But now, the front is now down all the way. When I start the car, the warning message comes on but after the car comes up to normal level, the message goes away. I tried finding the crack on the top of the shock tower. I found a crack but with some soapy water, still cannot see any bubbles. When I drive the car and go over any dip/bump, you can clearly hear this rush of air going squish from the front driver side. I jacked up the car yesterday and pulled off the wheel. The picture below is of the strut with the cover detached. Is this normal? I also included a picture of the top of the strut with the crack.

For those who have lived thru this problem, should I try the repair kit first or just replace the strut with an Arnott unit? Does replacing with the Arnott strut require any special tools?

engindin

Not normal, your strut is gone exactly same as mine, my front both was dropping overnight. When i checked i saw cracks also on top and tried with soapy water but did not observe any leak, i ordered two Arnotts and changed only the right one that was exactly like yours in your picture, now everything is fine with one spare Arnott strut.

When strut was out i could easily compress and extend it with my hand.

My left side has cracks on top but has no leaks, so i am not changing it.

Is that strut original? Top strut bolts seems strange to me.

mbenzagain

I could have sworn that the crack at the top of the strut was not there on Thursday, the day the warning light first came on. I think the crack must have happened yesterday after I jacked up that front left tire. At least for now, only one strut is bad. Even with the car sitting on the slope of the driveway, I can clearly see that this front left is the lowest.

In replacing your right strut, did it require any special tools at all? I think I will attempt to replace it myself.

engindin

Having ball joint seperator will be better and you need torque wrench.

Check this post for torque values;

https://mbworld.org/forums/s-class-w...tic-shock.html

And it has link there to Wallyp's post which contains more than enough information to do excellent job on your car.

cybertronicify

I just changed my strut like a week ago, so its fresh off my mind. Starting with step one...

1) Loosen the lug bolts on the wheel, only loosen don't take it off.

2) Jack the front end up with jack stands and leave the jack in the middle rubber jack point. (Make sure the rear wheels are chocked and the e brake is on)

3) Take the wheel off and observe. When you lifted the car did all the air escape? Do you see oil all over the bars, arms, and joints?

4) Follow the wire coming from the strut and take the connector off. First you take the metal clip off, then you just pull on the connector and you should have a 2 part connector that pulls out.

5) Get a wrench and carefully loosen the air line, make sure you don't overdo it and make the line pop off.

6) When all the air is out of the strut, remove the lower 2 HEX set screws. Push on the brake caliper with your foot and move the strut off the joint.

7) Go up and take off the 3 screws holding the strut in place. Great to have a buddy hold the strut while you do that.

8) Get your new strut and match it up with the old one. You should see no more than some sticker changes and maybe top rubber change. Everything else should be the same.

9) If you have the Arnott strut, then it is most likely fully extended. I didn't want to damage my alignment so I did not take any screws for my joints off. Go and position the strut into place and try to screw in as many screws as you can on the top of the strut. (those 3 nuts)

10) Have a friend step down on the brake caliper enough for you to slide the bottom of the strut over the ball joint.

11) Once that is done. Screw the 3 nuts in put the two hex bolts in. Put the airline back in, and plug the wire in. Put the wheel on and lower the car slowly. Start the car and let the compressor run and start lowering the car slowly making sure the strut is not bottomed out, yet low enough so that the level sensor knows to start pumping. Don't forget to tighten the lug bolts.

12) AGAIN!!! Don't forget to tighten the lug bolts....... I forgot... Almost totaled the car.


Its very late here so anyone want to add on to that, feel free.

mbenzagain

Jason,
Thanks for writing up the replacement process, still fresh in your memory. I noticed you did not remove the ball joint any more, is that right? Is it necessary to lift up the whole front end or will one side be sufficient. I only need to replace the driver side.

Thanks again.

Andrew

cybertronicify

Lifting the whole front end is better because the sway bar will get in the way. Yes there was no ball joints removed. Because usually it would mess up the alignment, and you need that tool.

mbenzagain

So I tried to replace the strut today.

Funny thing happened. I thought the passenger side was ok but when I spray it with soapy water today, it was bubbling like crazy.

On to the bad strut - driver side. I got it out but could not put the new one in. It is fully extended. How do you compress it? I did not remove the ball joint, but not for not trying. It did not budge. So I put the old strut back on as I was loosing daylight and I was in the common area of our HOA.

So of course the airmatic warning light came on again but I managed to get the car back on the driveway.

The car is sitting back all the way down again on the driver side. The passenger side seems normal height.

Help.

cybertronicify

One way you can try is to connect the release valve back up to the car and let the car send the signal to release air. I tried that on mines and it didn't do anything. I just had a buddy push down on the whole brake assembly while I struggle to put the bottom of the shock over the ball joint. It takes a while, but you will get it.

FYI Careful with the rubber boot on the ball joint. If it falls off, you will need to put it back on. Pain in the ***.

engindin

If you follow below you can do it,

* Lift the car from both sides, put on jack stands
* remove upper control arm ball joint to steering knuckle(replace self locking nut)
* remove old strut
* put new one and softly tighten top nuts
* put lever between lower control arm and strut bottom to put strut on to ball joint

if your car lower overnight check;
*Torque strut bushing
*Outer Tie rod ball joints

I am not sure but I think this lowering-raising cycle damages them.

mbenzagain

I tried to do the replacement again on Friday, this time removing the upper control arm ball joint, thinking it might help. No success as I still could not get the bottom of the new strut onto the ball joint. In the process, I think I tore up part of the rubber on the ball joint and the nut also is now just spinning the whole ball joint when I try to tighten the bolt.

I decided to give up and called a local MB indie shop. They said they do not take customer parts for repair work. I described to the head mechanic what I had done. He advised me to get a big pry bar and do it again and it should work.

Today, I tried it again this time with the big heavy pry bar. And I did not remove the control arm ball joint anymore since I could not remove/tighten the nut anyway. I had my son help me by standing on the pry bar and finally got it in.

I replaced the passenger side as well without need of the pry bar. It went very easily.

I have driven the car out on a 40 mile drive and everything seems to be just fine.

The only other difficulty with this job was getting the sensors plugged back into their socket just because the space is so restricted.

Thanks for all the help.

PS. I called the indie shop again about the control arm and they said they would charge $1500 to replace both sides and alignment! And they said both sides have to be done together.