w4sim

Hello all

Car has been sagging on rear left side after a few hours if left switched off.

So we removed the valve block, cleaned it quite thoroughly, put it all back together again and then tried the rodeo. But before the rodeo i made sure there was enough fluid in the tank, topped it up.

Naturally the back end of the car was nearly touching the floor, so after topping up the fluid we started it up, kept an eye on the fluid and waited for the back end to rise. It did not rise . . . . not even after 5 minutes of idling. So i hit the raise button and then it all raised, fluid went down a little bit so i topped it up again and let the car idle.

But i think i must have got a bit too ambitious filling it up because when we did the rodeo after about a minute into it the fluid started leaking out from the reservoir dip stick, quite a site that was.

Now im letting the car rest for a while but now if i start the car up and raise it with the interior button all the fluid goes down to the bottom of the tank, so i topped it up and dropped the car via the button again. All the fluid i just topped up came straight back out of the top.

So not quite sure what its doing here but somethings not right? All i know is that its better to have too much in it than to let it run to the bottom.

Shall i just do another rodeo on it as im guessing it will only leak out enough fluid from the dipstick as it deems necessary and not empty the whole system out and run the pump on air?

w4sim

Some suggestions are pointing at air being trapped in the system.

Will a rodeo get rid of that or do i need to locate and open a bleed valve somewhere?

Pentosin isnt the most cheapest of fluids for the car to be chucking out like that, its acting like a bad drunk thats just "barfing" out everything it takes in.

Thanks.

alx

Keep enough so you don't see the bottom of the tank at all times. Rodeo several times when pentosin is at opereting temp (hot to the touch). The system should self purge. Yes- you have air trapped somewhere.

w4sim

My guess is that we lost approx 1litre-1.5litres of fluid when the valve block was out.

I had not even put half a litre back in yet before it all started spewing out again, and it must have burped that half a litre back out within minutes.

We have left the car over the pit in the High position and will see in the morning if it has sank in any corner.

Normal would be for it to sink in the rear left corner as it has been doing for a couple of weeks now.

However if its still in the high position in all 4 corners then i think the initial problem has been solved and now we will only need to rodeo it for a couple of times.

Fingers crossed it will still be in the high position.

w4sim

Is there any particular method to set the correct level of fluid before starting the rodeo?

For example, have the suspension in the High position, car idling and the fluid at the lower mark on the dipstick etc etc?

I dont want the fluid level to be too high as it will start coming out again, but yet dont want it to be too low so as to run the risk of air getting into the pump. I will be keeping an eye on the fluid the entire time the rodeo is running but just could do with a starting point?

Thanks.

awiner

Keep the fluid level about 6-8mm from the top line when the car is off.

Too high and it will vent as you've noticed.

w4sim

Does the position of the suspension matter, high or low?

Thanks.

w4sim

Kept the suspension in the high position, kept the fluid level between the high and low markers on the dipstick and rodeo'd it. No spillages or leaks. So rodeo'd it again.

havnt really had a chance to drive it yet but will do later tonight.

So far its not sagged in any corner and the fluid level has not gone down either.

alx

It burped

w4sim

Well, its about the best way i can put it.

It actually burped twice before it really puked, but either way, a lot of fluid came out. (a lot of expensive bloody fluid )

w4sim

Anyways, bottom line to this, left it overnight and it did not sag nor did the fluid level move up or down.

Checked the fluid level to be right between the high and low marks on the dipstick and then did the rodeo. All turned out fine, no loss of fluid this time.

Iv taken it for a 50 mile drive with no dramas and so far no error messages either, and after a couple of hours it still has not sagged.

Wont get a complete picture for a few days but i think we pretty much got it this time.

RoCL

Just to make sure I undersrood correctly...the trapped air was purged by the abc system on its own? This happened by it burping/puking fluid a few times?

RoCL

You only cleaned the valve block? You didn't rebuild it? How long did it take you?

Just curious b/c I suspect I may have to do the same.

w4sim

Sorry, the car was burping/puking the fluid out of the reservoir when either we were raising/lowering the suspension with the interior button or when we had it on full rodeo. So it was only bring fluid out when the suspension was moving.

I guess by the time we stopped the rodeo after a couple of minutes most, if not all, of the air must have come out. But just as a precaution we left it standing overnight to see what it would do.

The system WILL self purge but air will only come out when the suspension is being raised or lowered. It wont do anything if its just left to stand.

w4sim

There is no rebuild kit of any kind that i know of, a very few minor parts are replaceable but the majority of the work requires the block to simply be cleaned, and cleaned very thoroughly.

Have a look at this thread below which will assist you with pictures. But if you get stuck let me know. Just be very careful not to break the plastic clips that hold the valves in place, they are relatively cheap at about $10 each and theres only 2 in there . . . . . . only down side is that they come in a pack of 20. So if you break one, thats automatically $200

https://mbworld.org/forums/cl55-amg-...ock-today.html

RoCL

This is awesome!!! Thanks for the reference and the hint!

w4sim

Im a DIY mechanic and my mate is a full time mechanic. Between us we have a pit, jacks, stands and just about all the tools required for the job. The one thing we both have never worked on, is ABC suspension.

But to be honest, after having done a few jobs on it, its not as scary as people make it out to be. As a matter of fact so far its been relatively simple and straight forward. I usually tend to do my research on the subject first and if i find a thread with pictures on useful forums such as this then that makes life a hell of a lot easier.

We had allocated about 4 hours to remove, clean and re-install the rear valve block as we like to take things easy on this system. I think we must have been re-installing it in about 2.5 hours. And if we had to do it again i reckon we could do it within 1.5 hours.

Important lesson here - even if you are a full time mechanic, if you've never worked on ABC before, always always allocate extra time and always TAKE your time. You make a mistake by rushing it and it could be a very costly mistake indeed. Theres never any rush with ABC.