Replacing SLS Accumulators 300TD - PeachParts Mercedes-Benz Forum

tobybul · #1 01-21-2008, 10:15 PM

Planning on replacing SLS accumulators soon. Just wondering if its simply a swap.... and making sure oil at reservoir is correct?

JimmyL · #2 01-21-2008, 10:21 PM

It is very simple, and it doesn't leak as bad as you might think. Just use a good box end wrench to get the fittings loose and be sure and hand thread the lines into the new accumulators. It actually takes less than an hour.
Be sure and have the back of the wagon supported as it will drop at the struts when the fluid pressure is released!!

Bio300TDTdriver · #3 01-21-2008, 11:53 PM

Quote:

Originally Posted by JimmyL

It is very simple, and it doesn't leak as bad as you might think. Just use a good wrench to get the fittings loose and be sure and hand thread the lines into the new accumulators. It actually takes less than an hour.
Be sure and have the back of the wagon supported as it will drop at the struts when the fluid pressure is released!!

I'm going to be replacing my rear valve. Is the advice the same, support the rear end? How much fluid will I lose?

Chris

JimmyL · #4 01-22-2008, 12:03 AM

I've never undone the valve, so I'm not sure. But you hardly lose anything changing accumulators. Valve is lower so that may make a difference.
Yes, support car properly!! They drop like a rock.....

Douglas.Sherida · #5 01-22-2008, 06:05 AM

Anytime you open the SLS hydraulic system it will de-pressurize very quickly and could squish you if its unsupported (and your springs are weak).

There is a bleeder screw on the valve that allows you to direct the oil into a container when you bleed off the system pressure. Do that first!

Then just R & R the accumulators (or valve)

Like Jimmy said, use a flared box-end wrench on the hydraulic line fittings when you undo them and be sure to hand tighten them fully when reassembling.

When you undo the lines, get some golf tees and plug the open lines (I use the plastic plugs that came with my MityVac). This will really minimize fluid loss.

#6 01-22-2008, 06:24 AM

Please remember to use new fluid, don't try to reuse the old stuff that came out of the lines/accumulators.

In fact, if the SLS system has not been flushed in the last 2-5 years, now would be a perfect time to do so.

tobybul · #7 01-22-2008, 08:09 AM

Thanks, Fellas. I am assuming that my accumulators are kaput since the rear is bouncy. Shocks are actually fairly new. PO replaced it.

About flushing..... do you just drain it from a low-point?

vstech · #8 01-22-2008, 08:19 AM

ahhh, the shocks are new? you mean somebody changed the REAR shocks on a wagon recently? um, that's REALLY pricey. are you sure?

Shawn D. · #9 01-22-2008, 08:55 AM

I'd suggest changing the SLS filter if you haven't done so in a while.

tobybul · #10 01-22-2008, 09:53 AM

Quote:

Originally Posted by vstech

ahhh, the shocks are new? you mean somebody changed the REAR shocks on a wagon recently? um, that's REALLY pricey. are you sure?

qui, monsiuer.... I have the documentation from the shop that deeed eeet. And the shocks looks new too. I'm guessing however that they did not know exactly how the SLS worked so they never got to the accumulators....

Yep, it cost them over $800 for the shocks....

kerry · #11 01-22-2008, 10:11 AM

Just to be clear, so that future readers of this thread aren't mislead, the 'shocks' are not really shocks. They are hydraulic cylinders with the accumulators serving to dampen the movement.
We did have a poster who took her wagon to a mechanic who ordered 'shocks' for it, destroyed the hydraulic cylinders in the removal process and then claimed the 'shocks' didn't fit and now she'd have to foot the bill for the much more expensive correct parts.

Douglas.Sherida · #12 01-22-2008, 11:07 AM

Quote:

Originally Posted by tobybul

About flushing..... do you just drain it from a low-point?

Use the bleeder screw on the valve.

johninva · #13 01-22-2008, 01:37 PM

thread in the hydraulic lines before you tighten up the new accumulators to the underside of the vehicle

#14 01-22-2008, 07:58 PM

Quote:

Originally Posted by Douglas.Sherida

Use the bleeder screw on the valve.

No. Unscrew the return line at the tank and catch the old fluid in a bucket/bottle, get out as much of the old fluid as possible from the tank, fill the tank with new fluid, start the engine, top up the tank with new fluid as needed until the fluid coming out of the return line is clean (Having a helper bounce on the back end will get out more of the old fluid), change the filter and reinstall the return line.

Douglas.Sherida · #15 01-22-2008, 08:35 PM

FI is right. He proposes a much better way to flush the system.

I wasn't thinking.

Draining at the valve won't flush the return line, but it will flush the accumulators/actuators more thoroughly.

Ideally, you would do both. Remove the return line and put it in a bottle, drain the tank, bleed at the valve. Start until it pumps up the rear, stop engine, drain at the valve, repeat until it drains clear at the valve. Then finish the flush process back at the return line.