I recently realized that my 2002 CL500's right side is about 1/4 of an inch higher than the left side. I have been reading countless threads about ABC problems, but I can not figure out what exactly is the culprit.

Additional to the ride height difference between left and the right side; when the car sits more than 2 days; left side goes even lower. When I start the car it levels again.

I never get a warning message like others with ABC problems mentioned.

Can anyone point me to the right direction?

Thanks!

 

My '04 CL500 does the same thing. Mine has some "seepage" at the left front strut. It has used less than 1 liter of fluid in the 2 years that I've owned the car. There are no ABC warning lights or fluid spots under the car. Be sure to check your fluid even if you don't see any leaks. As far as the strut goes,(if that's your problem), they are indeed expensive to repair. If you have a warranty I would definitely get it checked out. If not, at least keep your ABC fluid topped off.

 

who service your CL TamVette,
the reason why i ask because we live in the same city

 

Hey Wease,

I recently bought the car locally. Previous owner took it to Phil Smart in Seattle. He spoke highly of them but I do not have any experience with them myself.

 

My 2001 does the same thing except I have not noticed any height difference between the left and right. When it sits undriven for a period of days, the left front strut sinks until it is put in gear and the system pressures up again. I also never get warnings except when it is sitting low before it pressures up. If you find an answer, please post it here. My mechanic has looked at it and said the front strut will need replacing but I haven't fixed it because it has been doing that for the past 2-3 years and it hasn't had any problems if driven daily.

 

Check the ABC reservoir. You want to make sure it doesn't run dry, or the pump will burn out.

You can have two kinds of leaks, either the strut or the valve block. If the strut leaks, you loose fluid and can run the pump dry. Either replace it or watch the fluid level. If the valve block leaks, it just leaks back into the reservoir, so it's not a big deal. I find the more you drive it, the less you have issues with ABC.

 

You're a good man to keep repeating this advice for us!

 

Other components known for leaking are the various hoses.

 

This sounds like an ABC leak. If it is from the strut it is pricey.

We are working with a company who rebuilds these at a great price. If it turns out that you need a new strut or two, let me know.

 

These are not air shocks.

http://www.arnottindustries.com/part...18_pid144.html

 

Since the car has been doing it for years and the pump hasn't run dry (if it was the strut it would have bled it dry by now), I think the leak is from the valve block. I was going to check if it was from the o-ring at the valve block when I got a chance but I would like to make a pre-emptive repair if it's something worse. I am glad to know the whole history of the car since new, so I know it was driven almost daily for the past 10 years and hasn't had any ABC problems besides the sagging if it sits for a few days.

 

The sagging is normal. There aren't many that don't.

 

Good point. I know the hoses can fail dramatically (explode). Do they ever get a slow leak?

 

Agree that this is the valve block if the fluid never gets low, and also agree that it is normal. Even Mercedes says that if it sags after 5 to 7 days, that it's normal.

The valve block actually doesn't have rubber o-rings, it's metal on metal. They did this for reliability, because rubber seals would go bad. The downside is that there's always some amount of leakage since metal on metal doesn't seal as well.

The new valve block design is supposed to be more reliable, but unless it is leaking while you drive, I don't see much point in changing.

 

Well if it ain't broke, don't fix it. I'll check the hoses, valve block, and reservoir anyways. It's ironic that Mercedes did metal o-rings "for reliability" and wanted to avoid a service item like a rubber seal, and also that a "tolerable degree of broken" is acceptable or normal. SO frustrating and such a shame, but I digress.

 

It's like an engine. Rubber o-rings couldn't survive the pressure, repeated abrasion, and heat in an engine. So they use metal rings on the pistons. They don't seal as well, so you always have some amount of blow by (leakage). When the rings get too bad, you lose compression.

It's unfortunate, but it's the downside of using a hydraulic suspension.

 

The valve block pressure sensor has an O-ring seal and that can be changed as a preventative measure, or if leaks are apparent from the valve block.

It's a cheap, but effective fix.

 

Just wanted to update my situation:

I checked the fluid level and it was a little low; so I added CHF 11s fluid. Now when I leave the car for the night; I leave the car on high suspension level setting(2 red lights on). I left the car parked for 4 days and it did not sag. I am not sure why this helps at all; I am guessing somehow leaving it on high setting is easier on the ABC system, maybe the valves.

I did not see any leaks anywhere, but even if I have a leak somewhere it should very small. I won't do anything other than checking fluid levels every couple weeks at this point.

Thanks for the information all you guys provided!

 

Someone on BenzWorld came to the same conclusion after observing his SL500s ABC suspension and the theory was supported by a MBZ technician, who is also a moderator over there.

His reasoning was to leave the car in the highest ABC postion if parking for more than a few days.

The valve blocks are under pressure when set in the raised positon and they will be clamped closed - this helps to keep them working optimally and also allows more suspension travel before the 'car too low' message is shown.

 

had my '04 W215 parked in the garage for a couple weeks. it's been quite cold here (near zero degrees Fahrenheit). the front left (driver) side dropped dramatically yesterday or today. I hadn't noticed any lowering til then. this is the first time mine has ever dropped this low. the good news is that it straightened itself out after starting/driving. I've attached before & after pics.

 

i have this theory about fluid leaks: catch the evidence.

so, i put down a layer of vizqueen[plastic sheeting] and park the car on it.

if there are any fluid leaks, the fluid will be captured, retained. and virtually underneath the site of the leak. observing that evidence, you will know where to conduct a more specific investigation.

i have also found that the abc system in my cl500 coupe, left idle and sitting for two months, was down all around, and not equally. starting the car, it would not normalize until i elevated the ride height to maximum. doing that, everything normalized.

since then, when i put it away for any length of time[a week], i sequester it at maximum ride height. returning to it, i find that there are no annunciated abc issues.

for what it is worth.

 

This only gives you a vague idea of the location of the leak because of the full plastic panels under the car, often small leaks will not even drop threw the paneling but will lodge in the indents of those panels.

It is a good technique, but more investigation is necessary.

 

As always great information, could someone kindly confirm that leaving ABC in it's position 2 height setting, when parked for a few months, not have a bad effect on the system.

My S55 kompressor, bought new in 2005, lives it's life completely on the floor, I drive her ocassionally, as all our experiences, once fired up, it just self corrects the height. With only 17000 Kilometers on the clock, she still drives like the day I took delivery of her.

What I've noticed sometimes on an un-even surface, when the car is parked, the suspension seems to auto level the car, lowering itself on any given wheel, front, rear, left side or right side, or either the entire left or right side sags, completely independant of each other. All this is normal.

I would have thought that keeping it higher up would mean much more pressure on the ABC pump and hoses, MB cars equipped with ABC are heavy weights.

I still have full mobilo warranty on this vehicle and will have an extended Daimler AG South African warranty, thanks to the low mileage and never having claimed for anything major on this vehicle.

 

Hi, as some of you know my CL suspension is lowered by 2-3 days if the car is stationary in the garage, to boot I get the red message and I have to give the button that raises the car on two levels and everything returns to normal, I made several trips to Europe and had no problems of suspension, the liquid is at normal level (I have to change the Pentosin and filter), now I see the message I left my car Ifari at the highest level for three days and have not downloaded anything, I'll leave it another day and not start then I will tell you if there is new news.
Best Regards

 

Likewise Matias, thank you.

I believe ALL CLs lower after being parked a few days due to the metal valve block seats and it is an accepted circumstance according to MBZ.

If you should see the 'red' message, you do not need to be alarmed, or have to push the button to lift the car; because the car will raise itself once it is put in gear and the brake pedal is released.

I personally just put the car in gear after the motor has warmed up and allow the suspension to gently raise on it's own after being parked for days/weeks at a time and I should get the 'red' message.

My thinking is that it is easier on the pump this way, because the ABC fluid is able to flow thru the struts etc during the warm up time and the pump is under less load and primed imo.

Best wishes.