Pictorial: Replacing SLS Accumulators on 300TD Wagon
I changed my Self Leveling Suspension accumulators out today. I was anticipating a grueling task, but although messy, I found it surprisingly simple to do. I ordered these accumulators from Mercedes Source and looked for a pictorial on how to do this, without luck. It's for this reason that I am posting some pictures and tips.
You'll see that the pictures that I took are after the fact, but with this simple procedure, I hope to just get you familiar with what you're going to be facing. The rest is pretty self-explanatory.
First, jack up the rear end of your vehicle and use proper jack stands to support it. Remember that you're messing with the system that adjusts the level of the rear end. MAKE SURE TO BRACE THE FRAME, NOT JUST THE WHEELS!
I take no responsibility for your stupidity. If you bleed the system, your rear end can drop! Not good if you're under it.
Next, get under the car and bleed pressure from the system. Make sure you wear safety glasses for this. Fluid may be under pressure! To bleed pressure from the system, loosen the system bleeding nipple. This is located on the SLS valve just in front of the fuel tank, and can be found in picture #1. It's the nipple fitting that's now wet with hydraulic fluid. There is a rubber cover over the nipple that you will remove, and you will unscrew the fitting to release pressure. This requires an 11mm end wrench.
After there is no pressure, you will now focus on the accumulators. There are 3 11mm screws that hold the accumulators to the frame, 1 banjo fitting requiring a 17mm wrench, and one pressure fitting requiring an 11mm wrench. From here, it's pretty self explanatory. Just remove and replace the accumulators and tighten everything back up. I hope this proves useful for someone. Take a look at the pictures to understand what you're up against. Remember that you're going to have hydraulic fluid dripping down, so have something ready to catch it.
This job was surprisingly easy. The key is to do everything right
Just wanted to do a followup after the test drive.
For those of you who have an issue with rear suspension, or those who don't really know, you need to do this.
I didn't know what I was missing until I replaced these accumulators. What a difference this makes! It feels like a Cadillac in the rear now! Big, noticeable difference!
Also, I didn't think this would do anything for sag, but it has. The rear does not sag between parking at night and driving in the morning, and it seems to ride just a little higher. I don't have to wait 5-10 seconds anymore for the rear to come back up before driving.
Discuss this DIY here.