sl65user

I noticed the pulsation dampener part that fits onto the abc pump in the engine bay says that it does not fit 2008 sl65 in particular, only MY2013-2014, but does the 2008 sl600 and sl55. I am wondering why this may be, it looks the same from what I can see. I have read another thread on the internet mentioning something about a different clearance size, but no definitive information. Seems odd they would make an entirely different dampener for one model even though there seems to be plenty of space, and not have the part available to order. I am experiencing the hum sound and would like to replace it. Also seems possible to unscrew it without moving the pump, just have to hold some of the hoses out of the way. Anyone have experience with replacing this part on a 2007 or 2008 sl65?

George993

@sl65user so have you done it and how was it? Did you have to release any pressure first? Or just unscrew the dumper? Was there a lot of fluid leak? thanks

sl65user

I tried but the dampener is torqued down so hard
it was not coming off easily and was rounding off the bolt on top. I ordered some bolt extractors and will try again once they arrive. Heard reports of it being so tough to remove that the welded bolt on top actually comes off so hopefully that does not happen here. May try to put on some penetrating oil. Good thing is that there is enough clearance in the sl65 engine area that you can get to it without unscrewing the pump, you just have to take the air filter off, though the dampener is at an angle towards the abc fluid reservoir so it's a bit tricky to get a wrench on it.

sl65user

Popped vehicle open again and luckily the damper came off easily this time with bolt extractor, must have loosened it enough before. There was no leakage or pressure at all, it just unscrewed and left a gap of air the same as what would be displaced by the threaded portion of the damper. When I screwed the new one on it seemed to be going on smoothly with no resistance but was somehow cross threading, it wasn't actually screwing on and I just moved it up and it came off. This caused some metal shavings on the thread that I had to clean out really well, hopefully I got everything. Went for a test drive for a bit and there is no more droning/humming noise. Feels good to get this replaced. I can confirm that the process for replacing the pulsation dampener on a 2008 sl65 (and probably 2007 as well) is very easy with no need to fiddle with the pump at all, and the same part as on all other vehicles with the damper attached to the pump fits. Only thing needed is to remove the air filter (3 screws, very simple) and the hose that attaches to it at the bottom. There is another hose that comes around the right side of the damper that you will have to push out of the way a bit to get a socket on, then you can use a wrench going in from the left side to unscrew the damper.

George993

I've also just done mine 2007 S600. Luckily the process was also very easy - the dampener came off using 17mm wrench which needed about as much torque as removing a wheel bolt. Also no fluid loss (not even a drop - level below the dampener). The process was about as difficult and as time consuming as changing a wheel - even though potentially more things could have gone wrong.

~tc~

Glad I found this thread. I took my new to me 2007 SL65 to the dealer for a full work up and they diagnosed a bad pulsation damper and reservoir. It looks to be a quite simple think to replace, I only have one question - can you use an impact on this, or does it need to be done by hand?

George993

I did not need an impact and I would not recommend it, could brake the reservoir apart, good luck anyway

~tc~

Wow, <2 hours including detailing the engine. Certainly not the scary operation it’s made out to be. A 17mm ratcheting end wrench (the one size I don’t have) is the ideal tool. Much easier to get a wrench on it than a socket.