TheSaint

I am going to replace the brake fluid on my 2003 SL R230 and come to think of the SBC brakes on the car.

I am first going to drain out all of the old brake fluid before putting in new brake fluid and then bleed the brake system

Is there anything i need to be aware of thinking of the SBC brakes on the car?

Gene Fiorot

You will need Dot 5 plus Fluid. You have to power flush and fill the system the same way.

cdk4219

When changing brake pads, there are precautions, as the system may engage when the door is opened. I always unplug the abc module when performing brake pad changes.

Tom Manning

Without STAR, this is one job that should really be done by the dealer.

You can pressurise the system with a power bleeder (no more than 10 - 15 psi) and push the fluid through the system to the bleeders on each wheel in turn until the fluid runs clear or changes colour, but this will not replace all the fluid.

Star cycles the SBC unit and empties it of all the old fluid. Without STAR you will not replace the old fluid in the SBC.

But we're not talking about a lot of fluid here so it's probably OK to do it the simple way with a power bleeder, which you definitely need as a minimum; something like the Motive or similar. If doing this way, don't turn the car on or press the pedal during the procedure.

TheSaint

I bought original Mercedes brake fluid part number: A 000 989 56 05 11 which is DOT 4 Plus brake fluid. This is what is needed i was told by Mercedes. I also think it says DOT 4 Plus in the owners manual.

I am sure i have enough brake fluid to flush to drain the system first and then bleed thru everything so the whole system will contain the new brake fluid.

Below is a picture of the brake fluid i got from Mercedes (with a discount)


Original Mercedes brake fluid part nr A 000 989 56 05 11, DOT 4 Plus for Mercedes SL R230 class

It says DOT 4 Plus brake fluid in the owners manual

The Owners Manual says DOT 4 Plus brake fluid

TheSaint

This i have read about the SBC brakes that you make sure that you disconnect the power to the SBC brakes.

But i am not going to change the brake pads since it is no need for it

TheSaint

With STAR and when you replace the brake fluid what does the Star system do?

Using a power suction/bleeder that hooks up to an air compressor should do the job i guess?

I was thinking of first of all to drain out all of the old brake fluid and hook up the brake bleeder to the air compressor and suck in all new brake fluid.
The car takes 1,05 liter brake fluid and i have 2 liters so that should be no problem
It should be okay to do it like this or?

Tom Manning

Dot 4 is fine to use. Dot 5 is only if you're going racing. It has a much higher boiling point.

With STAR and when you replace the brake fluid what does the Star system do?

Cycle the SBC pump to clear it of fluid.

Using a power suction/bleeder that hooks up to an air compressor should do the job i guess?

Get the Motive or similar. Forget the compressor. You only need a few psi to push the fluid through.

I was thinking of first of all to drain out all of the old brake fluid and hook up the brake bleeder to the air compressor and suck in all new brake fluid.
The car takes 1,05 liter brake fluid and i have 2 liters so that should be no problem
It should be okay to do it like this or?

No.

If not using STAR, then:

Suction out the fluid from the reservoir with a clean syringe
Refill with new fluid
Attach the Motive and pump up to 15 psi
Open the bleeder from the rear left and watch until the fluid changes colour or runs clear
Repeat for rear right, front left then front right
At no time allow the reservoir to run dry!

TheSaint

Thanks for letting me know

I had a feeling that there was something about the SBC brakes so i am glad i asked Having said that i will do the brake fluid change like you have explained

I will be careful not to let the reservoir un dry.

I will start with the right rear wheel (that is furthest away from the brake reservoir) then the left rear, so the front right and finally the left front

I have one brake bleeder pump that looks just like this Motive pump on the picture below where you can pump pressure and i also have a brake bleeder pump that you can hook up the air compressor.

Brake bleeder pump

Tom Manning

The hand-one above is the go. I'd be wary about putting more than 15 psi in the top of the reservoir. You just don't need any more than that; just enough to move the fluid through the system.

TheSaint

I agree I am sure that 10 psi is more than enough to change the brake fluid

Gene Fiorot

I took a spare brake fluid cap and drill a hole and installed a tire schrader valve and used a bicycle pump. Down Side had t keep refilling the master cyl.

TheSaint

Did you disconnect the SBC brakes or disconnect the negative battery cable/cables when replacing the brake fluid on your SL?

Gene Fiorot

I did not use this cap on a sl500. it was an older model Eclass. Do you have to do all that on the sl500?

TheSaint

I will just use vacuum replacing the brake fluid . If i was to replace the brake pads i would disconnect the SBC

Gene Fiorot

I did my rotors and pads and I did not do that. Is it required ? I had no issues.

A1EK

Changing the pads is a breeze, but as others have said you must must tell the car you are working on the brakes through the diagnostic if you have it, or disconnect the SBC with key well away from car.
It took me 30 mins to change my pads and 3 days to clear the fault on the dash at a garage because I did not disconnect the SBC, the ended up having to up date software on my car to clear the error.