The Mysterious Insides of an Accumulator Exposed!

[pcmaher]

Well, as some of you may know, I replaced the accumulators on my 95 S600. With the help of my fellow Forumers, I now understand exactly how the suspension works in this car. Thanks again to everyone who helped out. I thought it would be interesting to take a peek into one of my old accumulators. So, I cut one of the old ones open, and took some pictures for us all. I first drilled a small hole in the round end, just in case there was any gas charge left in there (safety glasses naturally). I doubted there was, but you never know. There was no gas at all. I held the accumulator in a table vise, and started at it with a hack saw. It took quite a while to cut the end off. It's made of a relatively soft steel, and the wall is about 1/8 inch thick. By the time I was done though, the hack saw and housing were smoking from the heat. After looking around the inside of the thing, I see how it's supposed to work. It's not a simple flat piece of rubber dividing the sphere...it's more like half a rubber ball inside the steel housing. The damage you see was caused by me sawing the thing in half. I thought that the rubber was more like a flat diaphram located at about the halfway point in the sphere. Picture a football with half of a contoured rubber bladder inside. The leather functions like the steel part, and the bladder functions as the rubber part does. I didn't see any holes or tears in the rubber. I'm guessing that the plastic piece you see in the center of the rubber is a check valve used to charge the sphere with nitrogen. Perhaps that slowly leaks over time. The check valve in my new accumulators was just visible in the larger of the two openings in the steel part. There was fluid on the wrong side of the bladder.