KLinNBC

Has anyone replaced the pulsation damper on a a 2009-2012 SL63? I've found a few posts related to pulsation dampers but none for this specific model. This is the updated ABC so the damper is piggy-backed on the tandem pump and looks to be very difficult to get at. The heads are substantially larger than the 5.0 or 5.5 V8 in regular R230's, the pump is really jammed in between block. head and inner fender. Hoping someone has done this and can offer insight. WIS says, like it does for the alternator and many other usually routine tasks, "first you take out the engine" or something to that effect. I'm trying to avoid that...

mb_texas

I tried and gave up on it as I could not gain access to the rear bolt. I even lifted up the engine a bit and moved the steering and ABC reservoirs out of the way. I was able to remove the front bolts and rear bracket but there was something else holding it in.

WIS says to lift engine and slide right. Not sure how high that means but after disconnecting the engine mount bolts from the front subframe and the transmission mount I jacked it up a couple of inches and was afraid to go any higher. I was tempted to remove the engine mount from the block to gain better access but my frustration level was too high at that point so I threw in the towel.

Am very interested i hearing how/if others accomplished this. I have a 2009 SL 63.

KLinNBC

Thanks very much for this, precisely what I needed to know and exactly what I didn't want to hear. Hope someone else replies with some secret method.

HLG600

How much higher was there room to go?

This frankly sounds like something I'd take to a reputable indy shop, and there isn't much I place in that category.

KLinNBC

Yes, MB_Texas: I assume you also undid the trans mounts. Can you say how much more the engine could be lifted, did it look possible to shift it to the right as WIS specifies? I'm considering using an engine hoist to lift as it should be possible to shift it right whereas when you lift from underneath it's limited to straight up more or less. But I don't want to go through all the work to find I can't lift and shift enough to get the freaking pump out.

mb_texas

I would say I lifted about 3 inches. Yes, I did unbolt the transmission mount and some hydraulic brackets under the alternator as specified in the WIS instructions. I stopped lifting when I noted the lower radiator hose was beginning to get tight. I had removed the fan so I had better access to the front. I could have drained the radiator and disconnect the radiator hose but as that was not called out in WIS I didn’t proceed.

I could not get a good visual on the backside of the tandem pump and my hands are too big to get a good feel behind it.

I was all fired up after reading Rudney’s approach but just didn’t have enough access to the rear. Between the exhaust manifold, drivers side engine mount, steering column and other piping it’s really tight. Perhaps if I had prior experience I would have had more success.

KLinNBC

I figure those interested in this thread will also be interested in the accumulators which WIS calls pressure reservoirs. I did both over the last two days. Not a job from hell but not that much fun. WIS is pretty good so I'll just throw out a few things/hint/observations:

Both front and rear require removal of the entire valve block, no short cuts. Unlike ABS1 the reservoirs are positioned at the rear of the block relative to access.

Getting the blocks out isn't hard, the front is actually easier than the rear.

The MB tool for the disconnect on two lines on the rear block is a waste of money, a cheap thin 14mm wrench could be easily used.

I had a box of hundreds of plastic plugs and caps saved from many purchases over the years, did I ever feel smug about this. You want to clean up the area before starting to disconnect anything, and I mean really clean. Lots of gentle scrubbing, rinsing and waiting to dry. And then you want to plug ports and cap lines. There's a fair bit of pushing/pulling/struggling and shoving things about and you want to be sure these are sealed off.

Releasing pressure using the bleed valve is required but you're going to get bathed in fluid anyway.

I filled a small squeeze bottle with the CHF11s and used it to flush ports while reassembling just to be double sure.

The ABS system had been flushed and filter changed just before I got acquired the car last year, fluid looked good, a little darker but green. So I only topped up afterwards about 1 liter.

Cycled the height a few times to check and top fluid and then ran the rodeo twice. Let it sit in place overnight. No errors, no leaks, all seems good. Pretty happy and confident that the new reservoirs are good for my expected lifespan.

The dreaded pulsation damper is being done in two weeks in Calgary at a MB dealer who has experience with it and the special cradle/lift to move the engine.

marcd7tx

I just replaced my front and rear accumulators on my 2009 SL63 IWC edition with 25k miles on the clock. Just had my pulsation damper replaced under a warranty repair and was hoping that would take care of the low hiss at the front driver side in the bumper where the front valve block lies. Since it didn't, I figured I'd replace both accumulators to see if that helped, and with 14 years on the originals I figured it wouldn't hurt! KLinNBC, with all due respect, I was able to replace both of mine without disconnecting any lines from the valve blocks at all. What was key for me was a 23mm or was it 25mm (Harbor Freight set) thin wrench and a lever tube from one of my jacks to get the front one off. For the front one, I did remove the majority of the mounting brackets (which takes some patience) holding the valve block on which gave me enough wiggle room to get the wrench onto the front accumulator. For the rear, I just released the top mounting nut to the bracket and some of the hose clamps which retain the ABC hoses to the frame of the vehicle and slid it out enough to wrench the old accumulator off. It slides out on a flexible plastic bracket which I imagine could snap if you're not careful sliding it out. I did depressurize the the two sides at the bleed nipples, even though i had the entire vehicle up on my quickjack for over 20 minutes, which supposedly depressurizes the system. On another note, I have two MB stamped OEM accumulators I may list for sale if anyone is interested.

This helped this hiss coming from the front valve block, but did not totally take it away. My car has never had a level issue, so I do not plan on tackling a rebuild of the valve blocks just yet as I change the fluid every two years max, even though it's still green. I will still run a rodeo soon, but she sat right up once I lowered her off the quickjack. I did crank it up and let it run while not fully lowered, but with the tires touching the ground before I finally let it sit without any support. Maybe this hiss is endemic on our cars. My MB dealer said they didn't know what causes the hiss and said they had another AMG SL in for service and it had the same hiss.

Anyway, good luck with the replacement of the accumulators! FWIW I ordered the Cortecos from FCP

Just realized you only wanted info about the pulse damper. My bad. I'll leave this up FWIW...

KLinNBC

In the absence of any other first-hand evidence I didn't think it was possible to get the rear accumulator off without complete removal of the valve block. Access to the the 3 mounting bolts and the hydraulic line on the back of the accumulator mean you have to slide the block all the way out of the track, I got it about halfway out and became concerned that I might kink one of the two hard lines into the block if I forced it. And yes, breaking the track was also on my mind. But it is possible so thanks for this! Although I hope that I'm never doing it again...

On the front I could get the thin wrench (27mm IIRC) on the accumulator with just the front wheel arch liner and under tray off but just barely, at an angle and therefore was worried about slipping/galling the nut. I thought about removing brackets for more room but decided that the removing the lines and dropping the valve was the easier route. I think it took less than an hour to do this, then 10 minutes on the bench to change the accumulator where it was very easy to ensure no dirt/dust/etc got in. less than 30 minutes to put it back in.

My mileage at this point is about 40,000 miles and all of that in Alberta and BC. Second owner, I'm pretty sure it wasn't winter driven but still, the residue of winter lingers into June here abouts and also my driveway is 1.6km, 1 mile long and it's gravel/dirt. So the amount of dirt around both valve blocks gave me pause, there is so much warning from all DIY as well as Mercedes shop instructions about how the least mote of dust can break the whole ABS. I was happy after I decided on removal to have gone that route, I am certain I completed a clean change-over. I suggest this is an important consideration for anyone contemplating this job and how to do it.

I also got the Coteco accumulators from FCP. My understanding is that Coteco makes the MB branded units.

mb_texas

When I replaced the front and rear accumulators, Corteco brand purchased from FCP Euro, I removed the lines from the valve block and also replaced the o-rings on the line fitting as they were no longer round but flattened. That was an added delay because I didn't originally plan to remove any fittings from the valve-block.

Removing the valve block made removing the accumulators much easier, in my opinion, as it took a lot, A LOT, of torque to remove them. This was on a '09 SL63. I concur that removing the valve-block also helps with keeping things clean as possible when replacing the accumulators.

HLG600

Some great info in this thread. Bookmarked for when I need to address this (hopefully) a ways down the road.

Thank you, gentlemen!

KLinNBC

I had the pulsation damper replaced at a dealer last week, perfect job and charged for 6 hours. I don't think I'll need to deal with this again in my or the car's lifetime...