Jud Chapin

Has anyone personally done a coolant system flush/replacement on their CL? If so, I appreciate some instructions.

~CL500~

I did mine a few months ago. The true and correct way involves draining the radiator, heater core and block. I admit, I only did the radiator. The MB fluid is rated at something like 150K miles. I do mine every 2 years 20K miles by the radiator only.

All you'll need is some MB fluid and distilled water as it's not pre-mixed.

1. Jack the car up.
2. Remove the first underbody panel, right under the radiator.
3. Open the coolant tank cap.
4. On the drivers side, bottom of the radiator you'll see a red knob on with a drain spout under it. Open it up and drain the fluid.
5. When all the fluid is removed, close the drain spout and re-attach paneling.
6. Fill up mixed coolant (50% Coolant/50% Distilled Water) into the coolant tank to the very top.
7. Start the car and run the heat on high for about 30 minutes.
8. When the heat finally gets warm, all the air should be out of the heater core and system for that matter.
9. Let the car cool down and open up the coolant tank and check the level. More than likely it dropped from bleeding the air in the system. Top off if necessary.

Since Mercedes designed the tank to be at the highest point of the engine, the cooling system is self bleeding.

Good luck

Jud Chapin

Thanks! That's what I was looking for...the rad drain plug. BTW, have you ever changed out the ABC pump?

~CL500~

NP.

The ABC pump is something I have not yet had the pleasure of changing. When mine started to whine I had it replaced under warranty. Looking at WIS, the procedure seems pretty straight forward (but very involved) given that you have the right tools to do the job. It also seems that it's strictly mechanical since you're essentially changing a fluid pump; but ask anyone else and they'll tell you otherwise. The ABC module however requires STAR configuration which stores all the suspension ride height settings, etc. I don't know if that is an absolute required task when changing the pump in addition to the rodeo which also requires STAR. Do a search on the W220 forum for ABC pump replacement. There are a few techs there who have advised against it and posted some of the required steps. I'm still on the fence.

I'm thinking of changing my rear valve block though, but am waiting until it becomes more of an issue. As of today, my car only sags in the rear after a few days which is no biggie.

Jud Chapin

Thanks for the info. As I mentioned previously, the pump is fine now but I've got just another 9 mos. left on my Starmark warranty and I'm hoping to get the pump replaced before it runs out. I don't know if you can BS MB into replacing it by telling them it has an intermittent wind but I'll find out later on if it doesn't go out by warranties end. What other work have you personally done on your '01 CL? One ABC problem I have is that the front left drops after the car sits for 3 weeks or so. MB says it's not a problem.

~CL500~

Yea. That might be tough to pull off if there are no issues with the pump. I'm told they have to send the replaced parts back in for inspection and if they're not faulty, they won't get paid for the warranty claim.

To date, here's what I've done riding solo (I might have missed something, but this is what I recall off the top of my head):

• Brake booster
• Brake fluid flush
• Brake pads
• Coolant flush
• Oil change
• ABC filter change and top off of fluid (Rodeo pending)
• MAF
• Engine air filters
• Cabin dust filter
• Cabin charcoal filter
• Spark plugs
• Fuel filter
• Accelerator pedal module
• EDIT: Transmission fluid and filter change

Pending items when I get some time:

• Rear ABC valve block
• Driver seat backrest position switch (seat backrest lock light remains illuminated)

A suspension drop after 3 weeks isn't something to worry about and would be difficult to justify a warranty claim for this. Although you might have a better chance getting a valve block replaced more so than the ABC pump as you exhibit a very early symptom for the former and none for the latter.

Just to compare, mine sits for the entire weekend and on Monday morning the rear is low enough to illuminate the ABC warning light. Engine on ride height is perfect though so only my return valves in the valve block are sticking. When the problem becomes more chronic, like dropping sooner or dropping while engine on, I will replace. I'm hoping I'll be able to rent a garage with a lift for a few hours because it would make the job so much easier instead of the driveway.

brokenstunter

Dont believe that crap! When mine did the one wheel sag it was due to the strut leaking. It was not cheap to repair!
Your dealer is bull****!
Mine was done under warranty, I would assume you have the same thing goin on. Go in and ask where in the owners manual or any other literature it says the car is to sag during normal opperation.
This is not normal on a properly working ABC setup.
Get it fixed and dont listen to their BS!

~CL500~

Good point brokenstunter. I forgot about a potential leaking strut, though I would have hoped they checked for this when the car was in their possession. Wishfull thinking I guess on my part.

A leaking valve block usually causes both sides of a single axle to drop somewhat evenly. If one wheel drops while the other 3 remain at the same height, then this may be indicative of a faulty strut.

Jud Chapin

How long did your car sit before dropping?

~CL500~

Being that the general consensus among dealers coast-to-coast is that ABC suspension drop after a few weeks is "normal behavior", I wonder if anyone has asked if there is an official memo from MB regarding this issue and what is the exact time threshold that warrants a valve replacement? 2, 3 or 4 weeks?

The common response is always "normal" and dealers are always reluctant to replace valve blocks until they're chronically impaired makes me wonder if they're just not able to get reimbursed because certain guidelines need to be met.

Jud, since you have a warranty and your CL is right up there at that higher time threshold, can you ask your dealer for some more information on the issue? Is there an internal memo of some sort that clearly indicates an acceptable time frame for a sagging suspension pertaining to valve blocks? Myself and I'm sure others, would really appreciate some solid answer on the matter and hopefully the "sag" debate can finally be put to rest. It would be great if they can print out the SB/memo as well.

Thanks man!

Jud Chapin

As a mater of fact, I do have a "DTB" from MB dated 9/4/07, which was given to me by the second MB dealer that went over my ABC system. Both gave the same response, "no problem". The first part of the DTB discusses the problem with a stored fault code which advises the dealer "to perform the correspondintg action based upon the present condition".

The second section discusses the problem. Here it addresses 2 situations. It first notes that "large temp. differences in the ABC suspension system between operating and when stationary for an extended period can also cause the vehicle to lower slightly. The lowering is caused by temp. dependent volume changes in the ABC oil within the suspension struts. The vehicle can lower up to 10 mm when the temp diff is 30 degrees C (ABC operating temp 20 degreesC / outside ambient temp -10 degreesC)."

"Condition 1:
If a vehicle lowers after being stationary (engine off) within approx. 1 week, this is likely due to internal leakage in the check valve of the front (Y36/1) or rear (Y36/2) axle valve blocks. The internal leakage is the result of deposits of contamination on the valve seat of the check valve. In order remove the deposits, flush the ABC system.

If the complaint still continues to occur after the above procedure, the respective valve block must be replaced..."

"Condition 2:
If a vehicle lowers only after being stationary (eng. off) for more that approx. 1 week, this is a characteristic of the hydraulic design and is not a complaint that requires a repair. The check valves in the front and rear axle valve blocks have a metal valve seat. The inherent design of this sealing method, required for system durability, permits a limited level of leakage which can result in the vehicle slowly lowering. If the vehicle does not lower significantly until after approx. one week has passed, do not perform any repair attempts."

Other than the various codes, that's pretty much it. If you'd like a copy, email me your fax # and I'll get it out to you.

~CL500~

That seems a bit different than what I have in WIS. Yes. Please email to me. Thanks again Jud!!!

PS. I'll PM you my email.

~CL500~

Thanks Jud. This document is similar to the WIS document that I found, only yours is much more detailed as there are time frames attached to it; Although, I might have the same document in WIS, but I have yet to find it.

They do explicitly say a drop occurring beyond a week does not warrant any repairs.

I found a reputable indy mechanic in my area that has STAR. He's been working on German cars for over 20 years and he knows ABC well. He's German himself so it's in the blood I guess.

I already swapped my filter to the 3 micron type. My next step is to do a rodeo (twice) to filter all the fluid and then change the filter again and see what happens with my rear valve block laziness. If i'm lucky, the thing is probably just really dirty.

My intent was to replace it because I didn't have much faith in the filter method solving the issue. I haven't heard of anyone on any MB board that has successfully resolved a sagging suspension with the fluid flush/filter. Who knows, maybe it does work. At this point I might as well try and maybe save the G note on the valve block for something else that's pending imminent failure.

FYI. There is a new procedure in WIS recommending the filter method instead of a flush for the ABC fluid. Basically, install the 3 micron filter and then conduct the rodeo for 2 consecutive sessions. Then replace the filter again. This ensures all the fluid traverses the new filter and cleans it.

Isn't it funny how this post started off as a coolant flush and then we ended up talking about ABC valve blocks

Jud Chapin

I failed to mention that the dealer did a flush on my ABC system to no avail. Another interesting point is that my susp. lowering seems to take longer than it used to. It never did it when I first got the car (2 years old, 15k miles) but when it started, it would take about 2 weeks and now it holds longer. Who knows?

I noticed that you changed your tranny fluid and filter. If you wouldn't mind, could you please send me instructions on how to do it when you get a chance. I just can't seem to get much info out of my WIS...perhaps I should read the instructions.

~CL500~

True. I have no doubt that the flush/filter is a good thing, but as a full cure, probably not. I agree, who knows.

I'll send you the WIS procedure. I did a hybrid type of solution which did not involve flushing out the lines as per WIS. WIS indicates that this is only necessary when the fluid is really dirty, which is always the case anyway. The transmission holds about 8qts total. I drained the pan (hex drain screw), changed the filter, cleaned the magnet and got about 4 qts out (use a measuring pail). While adding the fresh 4qts, I carefully measured the oil temperature by pinging the oil pan with a laser thermometer and then checking the dipstick level at 25C and 80C. I plan on siphoning out and refilling another 4 qts this way diluting the fluid with 8 qts. It's not 100%, more like 80%, but much better than before. Also, make sure you have a torque wrench and follow the WIS torque figures. You don't want to strip ANY bolts.

BTW, you'll have to remove the rear underbody engine panel to fully access the oil pan. Half of it is exposed when the panel is intact. When under there, you'll halso have a clear view of your main high pressure ABC line going to the pulsation damper from the pump. This is the line replaced under the recall. It runs right by the transmission bellhousing on the rear. Observe for any leaks while under there as well.

healer1340

My 01 cl55 with ABC has a leaking right front strut. I have the upper and lower mounts removed. The only thing preventing me from pulling the strut out is the hydraulic line. It's supposed to be a "quick disconnect", like an air hose, but perhaps there is a "trick" to it. Does anyone have experience with this? I also wonder if the strut can be rebuilt. Minehas 34,000 miles.
Thanks, Steve

~CL500~

Not sure exactly how it's disconnected as I've never replaced a strut. I do know however that the system must be bled and ABC fluid must be replenished after replacement.

M-bENZ

CL500,

Back to the coolant flush( radiator)....do u have to mix 50% of coolant and the other half with distill water ?? Can we just use 100% coolant by itself??? Im planning to change the coolant for my CLK .

Jud Chapin

Yes, that is the recommended mix. You definitely do not want to use 100% coolant.

M-bENZ

Thanks Jud Chapin but is there a meter or anything like that it'll tell u when you refill with 50% already and the rest just water ?? How many liter that we need to fill up ??? I heard that there is no radiator cap if so where do u refill it ?? Somone told me that is on the passenger side but where exactly is that ?

Thanks,

Andy

Jud Chapin

I always pre-mix the solution so I don't have to worry about the ratio and the amount to fill it up. As for the radiator cap, I don't know where it is on a CLK but it's got to be there some place. Look for the overflow plastic tank with a hose coming from the rad. If you can't find it, check on the CLK Forum if there is one.

M-bENZ

and how much water and coolant that I need ???

Thanks,

Andy

Jud Chapin

As I mentioned, "fill it up" to the level on the expansion tank and keep it at that level until the system is bled. Don't concern yourself with the system's capacity as you'll never get all the fluid out when you drain it. I would have 2 gallons of the unmixed coolant on hand when you do the job (unless you are just going to drain the rad, then 1 gal. should be enough) but you'll never use it all. Stick with MB coolant, about $23/gal. retail at your local stealer. Good luck!

ohlord

capacity is in your owners manual.
You can use zerex GO5 anti freeze it is the same solution and specs as the mb stuff at half the price.
You can even get it pre mixed 50/50
http://www.valvoline.com/pages/produ...asp?product=10

M-bENZ

Thanks Jud japan.


Ohlord,

Do u think I can get that G05 premixed from local here ? autozone or pepboy ??