Rockstar08

Hi,

I have just replaced the front left strut with a new one. It wont inflate. The new one arrived inflated, so I can be sure it was sealing ok. Also I sprayed soap around the air supply line at the top of the strut once installed, no leaks. I removed the air suply line to see if there was any air coming out of it when the compressor kicks on, nothing.

Does the system require a reset once a strut is replaced? if so are there any non-dealer methods to do this?

BlownV8

Is the compressor turning on?

Rockstar08

Yes, the other struts are inflating/deflating correctly. I can also tell no air is getting to the front left as its flat when i push the struts bag..

BlownV8

Double check the airline and that it is seated correctly. If so, unplug and reinstall the air compressor relay and fuse. It may work. Otherwise, you may have some other issue.

Rockstar08

Thanks, I removed the blue airline from the valve block, and blew it through with an airline, reinstalled on the top of the strut, managed to get some air in the strut, and checked for leaks, found none. Verified the compressor was working ok, the right side came straight up, which is what i would expect from the left.

I suspect a faulty, or slow valve in the block, as it appears to have risen slightly, I can get my hand horizontally between the wheel well and the top of the tire now. Although that might be the air i blew into the strut, i am not sure. Its tough to tell as the other struts will also affect the height. above the faulty one..

When my strut blew out on the freeway, the top of the shock deposted oil in the bellow, which came leaking out when i removed the old one. I suspect some of the strut oil may have been pushed back into the valve body?

Will cycle the system, raising and lowereing, its not showing malfuncation now. See what happens, if it doesn't go back to ride height, maybe remove the valve body and troubleshoot.

I think i seen a couple of videos on youtube.. will take a look..

Thinking about it logically, it could be a computer issue, not sending a signal to the valve block to open the valve..idk how the mercedes system works..

ItalianJoe1

If it's down and there's no error, it's possible your level sensor got hit while working on the car and that corner is low because the vehicle thinks it's at normal height.

mefferso

I agree with ItalianJoe1 to look at the height sensor next. When I change my rear air bags, they wouldn't inflate even after slowly lowering the rear end with the GL running. It wasn't until I put it in reverse with the brake pressed that they filled right up.

Rockstar08

I think ineed to get it checked out with a star diag. After driving for 10 miles or so the malfunction light comes on, am out of ideas..

Rockstar08

ok after re-starting approx 10 times and driving 50 miles or so, the strut did inflate, however its not quite to the same ride height as the previous one ( about 10mm difference ), so I guess it needs to be re-adapted/re-levelled using the star diag system, it also does go upto max height when the raise button is pressed. I guess having one worn strut and one new one, you could expect there to be a difference.

I read the manual at workshop-manuals.com, the workshop procedure calls for re-inflation using star once the strut/air spring is replaced so, without doing this, i suspect the cars computer stops the compressor after a period of time if the strut doesn't come upto ride height after a prescribed period of time then throws a malfunction error. Its possible restarting the car numerous times eventually fills the airspring. Just a guess.

Despite the difference in height the car still 'tracks' straight and does not pull to one side, which I thought strange, i'd expect that to happen.

Now i have noticed a knocking sound coming from the same wheel well, sounds like a ball-joint or sway bar link. I had a pry around with my pry-bar but didn't notice anything loose, also retightened the 3 nuts at the top of the strut and the upper control arm nut, but the sound persists. Any reccomendations on what else it could be?

mefferso

My sway bar links started making a knocking/popping after replacing the front struts. I was able to replicate the sound by lying on my back underneath the car right behind the front wheel and push it up and down with my hands continuously. I had to push pretty hard, but after a few times, I was able to get enough momentum to push it up and down high enough that the sway bar link starting popping. Its obviously easier to do it from the top but you can't hear exactly where it comes from. An alternative would be just have someone do it from the top and you lye underneath to see exactly where the popping is coming from.

Although that seems to be the most common source of that sound, one guy actually had a defective brand new strut from Arnott that was making a knocking sound. You should be able to easily find that thread through the search button.

Rockstar08

Thanks Mefferso, I guess I am used to seeing sway bar end links come out with a little force from a breaker bar. I can bounce the front end with no sound at all when its stationary. It does totally sound like an end link, when driving at low speeds over rough ground. I have replaced them before on other cars. I see they are a common cause for complaint, at $15 I might replace it anyway, as its an easy job.

I was wondering if it was the strut, was thinking the top nut might not be torqued down enough. I purchased a suncore new replacement ( not a refurb ). It came inflated, seems like a quality part.

I had replaced all the air struts on an older Range Rover l322, so I am used to this kind of work, just don't know anything Mercedes, this is the first one I have worked on.

Rockstar08

So I replaced the heoght sensor on the left front, made no difference at all. Goes to the same height as before, still has the malfunction error. I guess star diags will tell me more.

Rockstar08

So after reading a little about how the airmatic system operates, it seems that my air compressor is worn. After a period of time the compressor stops and a malfunction message is displayed, along with the slow inflation of the airstrut after it was replaced. It probably has a worn piston ring/seal as it can generate some pressure.

gl450x164

I have a brand new armott compressor for 300 shipped

alx

Star can confirm bad compressor, bad sensor, lack of calibration, reset valve block lock out. Stop guessing. Find somebody with star and troubleshoot once and for all.

Rockstar08

LOL.. You can pickup a new one for less than $250 with a 12 month warranty..

gl450x164

You can always buy **** ones for cheap...