whiskywizard

Has anyone here flushed brake fluid on a 2015 GLK? Any issue using a vacuum instead of pressure?

I completed most of the B0 service today on my wife's 2015 GLK250. Oil, filter, cabin filter, air filter, checked fluids, added DEF. I still need to change brake fluid, and I'll do that in a week or 2 when I take off the snow tires.

I have both a Motive pressure bleeder and vacuum pump but generally prefer vacuum as there less chance of a leak spraying brake fluid around under pressure.

Comments?

Plutoe

I'd use the method that you are most comfortable with!!

SAVZ

I did it with the mityvac vacuum, it took a while to do it this way, fluid was flowing very slow, i think next time im going to use pressure. Plus the old fluid looked almost identical to the new (both MB fluid), I think a different color fluid would have made think much easier too.

whiskywizard

Thanks SAVZ. I did the job yesterday, using my Motive pressure pump. No issues encountered.
I agree about the colour difference, or lack of difference. The wife's GLK is about 22 mo old, and 55,000km so the old brake fluid still looked like new. I miss the old ATE Super Blue brake fluid. Alternating between the Super Blue and the regular amber Typ 200 really showed clearly when you'd pushed the old fluid through with new.

uniplexed

I remember that I have read a post in somewhere (can't find it now) that newer MB models need Xentry (or MB-specific OBD II scanner) to command car computer to flush the whole brake fluid. Is it true? Mine is 2013 GLK250 and thinking to bleed it soon and wondering if the old school method would be okay with it.

John CC

To bleed the system after something like a caliper change, you should be able to do it the "conventional" way. If you want to flush the system of all old fluid you need to be able to trigger the ABS system.

Mmr1

How do I trigger the ABS system in my garage with hand tools and no experience?

uniplexed

Or... would this work?

John CC

No way that I know of. You need a software package that will activate the ABS pump. Otherwise the fluid in the ABS system stays trapped in there and cannot be exchanges with the rest of the system.No, that's just to make it easier for one person to bleed the brakes. It doesn't activate the ABS system.

Mmr1

So with a regular brake fluid flush, the fluid in the abs never gets changed , or circulates ? It stays old ?

John CC

It circulates if the ABS gets activated, and gradually mixes with the new fluid, so it's not a total loss.

uniplexed

Hmm that sounds like we should go to dealership service or MB-specialized shop for brake bleeding… like for changing transmission oil? I don’t think that local brake/muffler shop would follow the right process for ABS (or even don’t have a device to activate ABS).

Mmr1

Do abs modules fail often?

John CC

No, not that I am aware of.

Don't confuse bleeding, which is unchanged from the advent of hydraulic brakes, with flushing or changing the fluid. To get all the old fluid out you need a way to activate the ABS module. I should think that any independent business that services Mercedes on a regular basis would be able to do this. Also, I would expect at least some of these DIY scanner systems could also do it.

Odd Piggy

Mid level scanners with 2way communication (not just code reset requests) within the price range of DIYers can access the ABS controls. Code readers, even if they can see ABS codes, cannot. If you intend to do your own trouble shooting and repairs, it might be worth the cost, and be certain ABS control is specified in the description. If not, find an independent familiar with Mercedes to do it.

Mmr1

Is the abs the same system that controls , Traction Control? If so then in snow, when it activates , would it circulate in any new fluid?

John CC

Traction control utilizes ABS, and yes, if it activates that will circulate the fluid. If you have snow and/or ice available you can activate it yourself...