100% Free

No Scanner Needed

Carly logo
Prices

oskarmayer8

Brake Booster Issue on M Klasse W164

My 2010 Mercedes M Klasse with a gasoline engine is throwing a fit. The speedometer keeps flashing an error message, and the braking performance is making me clench every time I hit the brake pedal. Feels like I'm driving with wooden blocks instead of hydraulic brakes. I scanned the car with a diagnostic tool, and it's showing a brake booster pressure sensor failure. Anyone else run into this? I'm suspecting maybe someone bled the brakes wrong at some point, messing with the pressure. Vehicle safety is definitely compromised here. Any thoughts before I start throwing replacement parts at it?

Summary of the thread

A 2010 Mercedes M Klasse owner experienced braking issues and a flashing error message, with a diagnostic tool indicating a brake booster pressure sensor failure. The problem likely stemmed from a recent brake line flush, suggesting improper bleeding might have introduced air into the system. A similar case was resolved by re-bleeding the brakes and replacing the faulty sensor, restoring normal braking performance. It is advised to have the vehicle checked by a qualified technician to ensure safety and proper diagnosis.

Did this summary help you solve your problem?

4 comment(s)

lukas_mystic9

I understand your concern regarding the brake booster issue on your M Klasse. I own the same model and had a similar experience some time ago. The symptoms you describe, including the error message and reduced braking efficiency, align with what I encountered. In my case, the problem was indeed related to the brake booster system. May I inquire if you have recently had any maintenance performed on your brake system?

oskarmayer8 (community.author)

Actually, yeah, about a month ago I had the brake lines flushed and new fluid put in. Now that I think about it, the problems started cropping up not long after. What exactly was the issue with yours? Was it the sensor itself or something else? And what was the fix? This is making me nuts...

lukas_mystic9

The brake lines being flushed recently certainly gives a clue to the origin of the problem. It is highly probable that there is a connection to the brake bleeding procedure. In my experience, the problem was diagnosed at a certified workshop, where they pinpointed the pressure sensor as the faulty component after carrying out diagnostic tests. I would recommend that you have the vehicle checked by a qualified technician. They will be able to determine whether the incorrect bleeding procedure has caused further damage. It is crucial to deal with this promptly, as it affects vehicle safety.

oskarmayer8 (community.author)

Just wanted to say thanks again for the input. Turns out you were spot on about the brake bleeding! Took it to a mechanic, and they confirmed the booster pressure sensor was shot because of air in the system. They re-bled the brakes properly and replaced the sensor. Cost me about 90€ for the replacement parts and labor. Brakes are back to normal now. Huge relief!

rmh_community_comment_box_header

community_crosslink_scanner_headline

community_crosslink_scanner_intro

community_crosslink_scanner_title

community_crosslink_scanner_price

community_crosslink_rmh_headline

community_crosslink_rmh_intro

community_crosslink_rmh_title

community_crosslink_rmh_subtitle

community_crosslink_rmh_brand

MERCEDES

community_crosslink_rmh_model

MKLASSE