driveability

Some time back my rear accumulator failed (blinked the ABC light over mild bumps and had a soft rear spring feel along with a harsh ride)


Two days ago I hit a high speed bump hard, one of those almost air born events. Feels like my rear accumulator failed again. Factory Ebay part any thoughts ?

awiner

Part for the front and rear accumulators is: A220-327-01-15

driveability

I have to remove it and test for rupture.

Exotic-metal55

I need to change mine as well but no light yet. Lot of hard launches at the track have not helped

NRL

still waiting for the accumulators in the mail..
I started by checking the level and changing out the ABC fluid in the reservoir to see if it improves..

DAS is showing 1.9Bar versus the 2.0Bar needed.. no other error codes.

Did a short test and the ride for small bumps is rough,sharp.. really looking like it's one for the accumulators. Don't know which one.

More symptoms, "burping" sound sometimes when I start it.. also a new sound sounding like a "super charger" when accelerating.. maybe it's the pump trying to keep the pressure up since the membrane on the accumulator broke..

Anyone want to guess which accumulator it is?

Front, Rear, Pulsation Damper, Air Cell?

awiner

I would guess front

NRL

Got it Jacked up.. starting the process of replacing all the accumulators..

First one was quick, the one behind the drivers front wheel... old part seems fine..doesn't seem to be bad.

The 2nd one I started to work on is the Pulsation Dampner, Passenger side Middle.. That one won't budge.. sprayed it, will try again later.

I think I'll do the rear accumulator (rear passenger side above diff) next, rear accumulator, should be easier..like the first.

I think the last accumulator is near where the fuel filter is.. also putting in a new fuel filter too.

Since it's on Jack stands, I might as well fix the famous transmission harness connector o-ring wicking issue..with the newer better part, along with a transmission drain and re-fill..

Blkvip

noob question. when changing them did you have to flush the fluid?

NRL

I'm going to flush it when I finish replacing all the accumulators. I'm thinking of bleeding the front and rear bleed points since the fluid seems quite dark.. but not sure if that's neccessary. I bought extra filters to keep filtering it, even bought a magnetic filter that I'll be adding inline just before the abc filter to pick up any metal if there are any..

You can do the procedure where you unplug the hose that goes to the top of the reservoir into a bucket and making sure you keep a fair amount of new abc fluid in the reservoir, just make sure it doesn't go empty when the engine is running and the abc fluid is flowing...

Before I started working on the accumulators:
I mytyvaccumed (fluid extractor) the old dark ABC fluid from the ABC reservoir with it on suspension on low (the button no LED) and replaced it with new ABC fluid (green, CHF11) and raised it (3 times) before I found out there was a bad ABC accumulator somewhere.



I'm replacing the rear accumulator tonight after unbolting the passenger side muffler to get at the old rear accumulator..

2 more to go..

NRL

Update:

I just finished swapping out 4 of them myself DYI, took me about a week working on it a bit at a time..
They are not all the same. The easiest one to get to is the Front Accumulator, take the driver side wheel off, remove the inner wheel well lining and you'll see it front cavity.. That one was the easiest to do for me.

The front one is the same part number is the rear accumulator, both of them the largest accumulator compared to the other two.

The other two are unique, found one near the fuel filter/ pump. This one was easy for me to remove compared to the other one which is on the passenger side near the front wheel underside area. That one was the hard one to remove because they are on rubber mounts so you can't get enough torque to get it off.. you'll need to hold it with a adjustable large cresent wrench hold the metal plate where the valve block is connected to and carefully unsrcrew it off.. I had to had a pipe extension over my thinset 24mm to get enough leverage to get that one off..

The rear accumulator is underneath the passenger side muffler, you have to undo the two 13mm bolts holding the muffler, and part of the heat shield but before you do, undo the rubbermounts that hold the exhaust up and a few other items.. this is needed so you can get that big accumulator out and put the new one in..

In my case, it was the pulsation dampner located right near the front passenger wheel, you can see it in a indent once you remove the wheel. Symptoms were no error codes other the when the nitrogren membrane must have broke, lost pressure, 190 psi afterwards, no leaks, rough freeway, just no damping in the suspension.

It finally died and I think it was because the dealer had over torqued it on there. I measured 60+NM before it would unscrew!

Just finished up today, just did a few tests, checked and topped off the ABC reservoir making sure it's right on the dip stick marks. Raised it a few times, no errors, no burping, no groaning...

It can be done DYI, but you need the right tool set of all kinds: 8,10,11,12,13,17,24mm wrenches / flare nut wrenches, thin set wrenches (that 24mm), sockets, long extentions, interchangble torque wrench for torque flare nuts to 50Nm, hydraulic jacks, jack stands, more safety jack stands, borescope! and more..
I'm getting a garage portable lift for sure soon.

JPhamily

Instead of replacing all four, is there anyway to check which one is ruptured by twisting it off?

awiner

Speaking in terms of extended mileage vehicles, if one is ruptured, the rest are well on their way.

JPhamily

Whats the update on the car, driving better now?

Exotic-metal55

Nice work on doing all the accumulators yourself. We assume all is working now and car is holding level?

NRL

yes, all done.. Level, no codes, no leaks, nice freeway ride.

I'm in test mode. I left the plastic guard covers off just to make sure there are no leaks anywhere.

I'll post my pics soon..

I worked on the replacing the transmission harness plug this weekend so the car was on jacks again. Transmission oil drained, pan cleaned and replacement of that inner harness plug that has two oil rings (newer different rubber o-rings).
That was actually more hairy getting it back in since it's obvious the new o-rings are slightly larger to keep the transmission oil for wicking into were the pins are. More hairy then replacing the accumulators..
Since I had the cover off the one accumulator that is near the fuel filter, I replaced the fuel filter also before that cover was put back on.. idle seems smoother.



Testing with some short and medium drives.. with no leaks, I'm checking very closely for leaks from the accumulator flare nut points and transmission pan, harness connector area..with a video bore-scope close up.
and probably jack the car up one more time to get the under body plastic covers back on..

Biggest recommendation I can give on doing this Job DYI is get some kind of lift, borrow a lift.. moving and jacking up with hydraulic jacks and using safety jacks was the most time consuming in a home garage.. even with the car jacked at the maximum height the safety jacks could go, I still had to be on my back doing yoga in getting it done..
But if you have the time to work on it alittle or as much as you can take every day, it can be done DYI.

I'm thinking of getting this QuickJack:
http://www.bendpak.com/Shop-Equipmen...k/BL-3500.aspx

not a bad price including shipping.

Dr Matt

Great info, but....

Not too impressed with the specs on that lift. Didn't see the price, but make sure if you buy it you get the 5000# lift as the 3500# is not strong enough for a CL. I'd suggest something more like this:

http://www.gregsmithequipment.com/Ma...ngle-Post-Lift

or even better

http://www.gregsmithequipment.com/At...e-Scissor-Lift

Welwynnick

Anybody here use a lift like that?
I'm thinking about getting one for myself. Fed up of dealer mechanics having it so easy.
Nick

NRL

Sorry, I linked the older 3500lbs QuickJack.. Here is the 5000lbs Quickjack:

http://www.bendpak.com/Shop-Equipmen...k/BL-5000.aspx


I called the company and discussed the weight of the CL65.. They say it's been tested up to 7500lbs (1.5 times).
I'm going to try it and have pre-ordered.
It'll probably take a month for delivery.

Let you guys know how it works out..

NRL

Update:

2nd Weekend in test mode.
Decided to jack it up one more time front and back and put the second plastic underbody shield (the one that covers the transmission lines and/or ABC lines).
Looked for leaks, none seen anywhere.

Left the front underbody shield off just in case to make the removal process quicker.

Just driving it around some 10-25miles ranges, the suspension in all modes felt incredible.
The tiny sharp bumps that I used to feel are mostly gone. Handles dips well.
Tried the Comfort mode with full suspension all the way to Sport and lowest.
All suspension modes seem very well damped.

Probably the way it feels when the car was brand new, really nice and comfy.

NRL

Front Driver Side Accumulator - Easiest To Replace








Passenger Side Accumulator

JPhamily

So its as easy as locating the accumulators and then twisting them off and twisting on the new one? How would you torque them? Planning to do this really soon.

tusabes

If you can please post pics and location of all 4 including the pulsation damper , and the parts cost for each

NRL

here is a mbworld link to a pic:
https://mbworld.org/forums/cl-class-...ck-please.html

and some more pics from these threads:
https://mbworld.org/forums/cl-class-...c-problem.html

JPhamily

CL55 and CL65 both have the same suspension right?

awiner

Yes