Mercedes-Benz E350 brake failure problems

Filed Oct 16, 2026 · Brakes · MD

The rear brake line corroded and developed an actual brake-fluid leak. The failure triggered a brake-system warning and created a risk of reduced braking capability or loss of braking if the leak worsened. The problem was confirmed by an authorized Mercedes-Benz dealership, which diagnosed corrosion of the brake line and recommended replacement. The dealer provided a repair estimate and later reduced the repair cost through a goodwill review coordinated with Mercedes-Benz USA. This was not simply surface rust discovered during routine maintenance. The corrosion progressed to the point of an active hydraulic brake-fluid leak. The vehicle had approximately 79,349 miles at the time of the failure. Mercedes-Benz had also recently replaced the rear subframe on this vehicle under an extended warranty related to corrosion. Because the brake lines are located in the same general rear-underbody area, I am concerned that the corrosion may have been present or visible during that earlier repair. I am also aware that the federal safety agency previously reviewed rear brake-line corrosion involving 2010-2015 Mercedes-Benz E-Class vehicles under Defect Petition DP20-004. I am submitting this complaint because, in my case, the corrosion progressed beyond surface deterioration to an actual brake-fluid leak. This happened all of a sudden while my wife was driving to work and could have resulted in serious injury or death. The vehicle and failed components are available for inspection upon request, to the extent they remain available at the repair facility.

Filed Oct 15, 2026 · Brakes · 151,000 miles · CA

The contact owns a 2006 Mercedes-Benz E350. While driving at 30 MPH, a "Reduced Braking Power" warning message was displayed on the instrument panel followed by an audible alarm. The brake pedal travelled to the floorboard, resulting in a significant loss of braking functionality. Additionally, the vehicle became stuck in second gear, requiring the driver to pull over and have the vehicle towed to the residence. The consumer performed an OBD II scan, but no diagnostic trouble codes related to the brake failure were retrieved. The manufacturer was notified and confirmed that there were no active recalls associated with the failure. The failure mileage was approximately 151,000.

Filed Sep 14, 2026 · Body, Brakes · 67,218 miles · VA

The contact owns a 2014 Mercedes-Benz E350. The contact stated that the brake pedal was spongy while depressed, with the "Brake System" and "Low Brake Fluid" warning lights displayed. The vehicle was taken to a dealer, and the brake fluid was topped off; however, the failure reoccurred in less than 24 hours, and the same warning lights were displayed on the instrument panel. The vehicle was taken back to the dealer, and the technician was informed that there appeared to be a brake leak. Upon inspection of the vehicle, the technician discovered that the subframe was severely corroded, which had caused the brake failure. The contact informed the dealer that there was a class action lawsuit for the failure. The dealer acknowledged that the failure was a known issue; however, no further assistance was provided. The manufacturer was not notified of the failure. The vehicle was repaired. The failure mileage was 67,218.

Filed Jun 1, 2026 · Brakes · NH

Brake failure due to leaking brake fluid after dealership conducted rear sub frame extended warranty coverage replacement and recent brake fluid services and after two (2) multi point inspections including video and reported “no items failed” and “no items cautioned.” Vehicle was released to me both times Vehicle was inspected and is available for further inspections. My safety was jeopardized due to brake system failure while traveling at high speed on public highway. The problem was confirmed by two (2) dealerships. “ Please see below for recommended repairs on your 2012 E350, VIN - [XXX] Inspection by a different Mercedes Benz dealership reported the following: [XXX] Concern – vehicle is leaking brake fluid from behind the drivers front wheel / tire Cause – Confirmed concern, installed vehicle on lift and found brake fluid dripping from plastic side panel under the drivers door. Brake fluid flush recently completed on vehicle by Portsmouth MB, verified bleeding valves on calipers are tight and not leakingRemoved paneling and found fluid is dripping from wheel well area. Removed left front wheel well cover, and found rear brake lines are leaking due to heavy corrosion and bubbling (see attached photo). Correction – Rear brake lines need to be replaced to repair. Due to corrosion, will require brake hoses due to rotted connections. Lines are formed, fitted and secured by technician during repair (they do not come pre-formed to vehicle). Repair Estimate – Labor ($199.88 / hr) 9 hours (includes diagnostic time), $1798.92 Parts, estimate $690 if no further connections are needed (tax included) Shop supplies, $26.95 Estimate $2520 total repair **Tech notes there is a fuel line running in an area of the brake lines that is showing bubbling in the metal, not yet leaking. Additional $375 parts and labor to replace if we replace with the brake lines. MB parts states there are only 2 of these lines remaining globally.” INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)

Filed Oct 23, 2025 · Brakes · 180,000 miles · TX

The contact called on behalf of the owner of a 2006 Mercedes-Benz E350. The contact stated that while his mother was driving at an undisclosed speed and approaching a traffic light, the brake pedal was depressed; however, the brakes failed to function as intended. The brake pedal was depressed down to the floorboard. The contact's mother used the parking brake to stop the vehicle. The ABS warning light was illuminated. The vehicle was towed to the residence and then to an independent mechanic. The vehicle was diagnosed with Sensotronic Brake Control (SBC) system failure. The contact was informed that the Sensotronic Brake Control system needed to be replaced. The vehicle remained with the mechanic unrepaired. The manufacturer was made aware of the failure and advised the contact to report the failure to the federal safety agency Hotline. The failure mileage was approximately 180,000.

Filed Sep 24, 2025 · Brakes · CT

My brakes failed, the rear brake lines had corroded.

Filed Aug 27, 2025 · Brakes, Engine · MA

Brake lines rust and corrode at the plastic support clips. Brake lines are not made from quality materials. Suffrage also corroded. Suffrage was changed by dealer though when vehicle was returned the Brake lines were broken. Car entered Suffrage service with brake lines intact, rusted i wouldn't doubt but intact. When returned after changing Suffrage, brake line was broken and leaking brake fluid. Extremely dangerous to return vehicle with broken brake lines and expected Owner to drive away with no brakes. Changing brake lines was offered at a cost of $4000 but the lines were not broken upon dropping off for service. Brake lines should be warrantied and changed to a less corrosive material. Engine mounts fail and cause vibration.

Filed Jul 18, 2025 · Brakes · VA

My brakes went out while I was driving my family on a road trip. After getting towed I inspected the brake lines and they are absolutely destroyed. This is clearly a design flaw by Mercedes. This needs to be recalled. You have to drop the rear subframe to repair this. Absolutely ridiculous.

Filed Jun 7, 2025 · Brakes · NY

Rear brake lines rusted out on top of rear subframe which is rusting out and caused immediate brake failure . Our lives and the lives of other were at risk because we were driving on highway and suddenly brakes went to floor and had complete loss of brakes There were no prior warnings no way to prevent this ...i see there is a recall on the subframe but not on the brake lines even though ive now read of this happening to many people

Filed Feb 5, 2025 · Brakes · MO

Was informed about the extended warranty for the rusting rear sub-frame issues on this make and year. Upon speaking with the dealership and further research online the rear hard brake lines are rusted as well and not covered by Mercedes. Upon further research this a common issue and danager to my safety and others as well. Upon work required to fix rear sub-frame would make it easier job to also replace rusted brakes lines. But Mercedes does not cover that and wants to charge customers a extra 3500$ to fix something that should not be happen as well. With the sub-frame out for replacement would make sense to replace other rusted parts with the extended warranty. It's a major safety issues already with rusted sub-frame and also added rusted brakes lines. This should be investigated further into to keep everyone safe. There are lot of owners unaware of this issues that could lead to brake failure. We use our brakes to stop and most new cars should not be having this issue so early.