Which parts fail
Components named in complaints (service brakes, ABS, rotors and pads, parking brake).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2012 Mercedes-Benz E350 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2012 Mercedes-Benz E350. The contact stated while driving at various speeds; when the brake pedal was depressed, the brake pedal failed to return to the original position. The contact stated that upon inspection, the brake pedal felt abnormally loose and there was a brake fluid leak present. The vehicle was taken to an independent mechanic where it was lifted and was noticed that the sub-frame was rusted. An appointment with the dealer was scheduled to inspect the vehicle as a second opinion. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 160,000.
I have video available that shows significant premature corrosion of the rear subframe and brake line. The safety of others will be put at risk at the time of failure. Failed subframes can lead to loss of control. This problem has been identified and the part inspected by a Mercedes dealership. There are no warning lamps or messages to alert the driver that failure is imminent. This was discovered in the process of the car being serviced for an unrelated emissions recall. Many Mercedes owners report having severe rear subframe and brake line corrosion issues on message boards. Some reported their cars unexpectedly sway and drift to one side while breaking. In multiple European countries, Mercedes is apparently aware of the problem and is voluntarily replacing the rear subframe for free. …
On my recent visit to my trusted independent service center, which specializes in Mercedes-Benz, they noticed serious corrosion problems. There were no symptoms to alert me to any problem. Also, I never received the notice from MB so how would I know? My mechanic asked me to sign a waiver (which I never have had to do before) that stated the rear subframe was rotted completely through; needs to be replaced ASAP; and is unsafe to drive. The rear brakes lines also had corrosion. This tells me the car is unsafe to drive, and must be fixed. It seems that MB issued an "extended warranty" to cover the rear subframe, but not the rear brake lines. I contacted MB Corporate who said they 'may' offer some assistance. I have an appointment next week with a MB dealer who must provide an estimate of the damage and cost to MB for their approval before doing any work. …
I recently took my 2012 Mercedes-Benz E350 to an authorized Mercedes-Benz dealership after experiencing corrosion of the rear subframe. The dealership confirmed and is servicing the vehicle under an active recall notice that extended the original New Vehicle Limited Warranty from 4 years/50,000 miles to 20 years /unlimited miles. After removing the subframe for repair, they observed serious corrosion of the brake lines. There had been no warnings or symptoms to alert me to any corrosion problems with the brake line prior to this. Most likely, the issue would not have been discovered if the dealership had not removed the subframe. The dealership advised me that this issue requires immediate service due to safety concerns (potential failure) as the braking system could fail while driving the vehicle. The cost to have the work done is $5800. …
On April 29, 2024, I was driving my 2012 E350 Mercedes and the brakes failed upon leaving an appointment. There was less than 10% stopping ability. Fortunately, I was able to use my transmission toggles and Emergency brake as back up, if needed. I immediately stopped to pick up brake fluid and filled the reservoir which was virtually empty. Drove the vehicle home, left it parked for two hours and then tried to then drive it again but to no avail. The system had "bled" all over my garage floor and driveway. As such it was taken to the dealership on a flatbed. Estimated repair... $1,700 This follows having to replace the cargo springs due to corrosion and breakage, the rear suspension sub assembly currently being replaced due to corrosion which Mercedes acknowledged is a problem and is covering under an extended warranty. …
The rear subframe got separated from chassis. I was driving to work and had to hard brake to void a collision with another vehicle all of a sudden vehicle shifted to the left and I ended up on a curb. Further inspection vehicle`s rear subframe rotted out due to rust. Also, both rear brake lines from abs module to calipers are damaged due to corrosion. I ended up replacing both brake lines and did not think too much of it and now I see a lot of people complaining about both brake line corrosion and subframe separation or excessive rust, casing rear subframe to fail. It is a very serios safety issue and Mercedes should hold accountable for these failures. My vehicle is 2012 Mercedes E350 and only has 118k miles on odometer. …
I purchased the car late April. I drove the car for three or four days and started noticing a rattling coming the front right part of the car (passenger side.). I chatted with the warranty company (SilverRock.). They asked me to take it to a Meineke auto repair facility in Olympia, WA. Meinke's mechanic diagnosed it as a loose component involving the brake caliper. He informed me they were covering it under the warranty, & asked me to bring the car back on Wednesday as he was short staffed. I brought the car back on Wednesday, it was there all day. He called late in the afternoon and informed me they found the problem and that SilverRock had amended the claim and refused to cover it. Told me it needed new brakes for 800+ bucks. That being said it was also sold to me with gouges out of several tires. Of which I have photos. This is inexcusable it is also a safety issue.
My car had a pool of brake fluid under the car and when I turned it on, it said the brake fluid was low. When I went to check the reservoir it was empty. The underpanels were removed and the brake lines were rotted out in several areas. I was shocked because my car is in mint condition and I have always avoided taking it out when the roads are salted in the winter. I am lucky this happened when the car was parked. This has never happened to the cars in my family which were never treated with as much care.
The rear subframe is corroded and needs to be replaces - there was no prior warning and the Benz dealer stated this is something that only is evident to even the most highly trained mechanics once it is at the point of total failure. The rear brake lines are also corroded and the Benz dealer will only pay for the subframe and not the very expensive rear brake line replacement which seems to be entirely related.
Brake line is thoroughly corroded, went to a repair shop, when they brought it back down, the Subframe collapsed. Mercedes has a 20 yr warranty on the subframe so they will cover that but want another $3K to fix the brake line that was obviously tied to the same mfr issue that the sub frame was in regards to rusting. Dealer won't take any responsibility for anything but the subframe.
NHTSA investigations
Rear brake line failure
On April 10, 2020, NHTSA's Office of Defects Investigation (ODI) received a defect petition from Mr. Surjit Singh alleging premature corrosion of the rear brake lines in his 2013 Mercedes-Benz E350 sedan. The petitioner states that he was recently informed by a Mercedes dealer service department that his car had severely rusted brake lines that need[ed] to be replaced immediately at a cost of about $3300.
Brake complaints in other E350 years
Frequently asked questions
How common are brake problems on the 2012 Mercedes-Benz E350?
NHTSA has 20 complaints about the brakes of the 2012 Mercedes-Benz E350, 9% of the model year's 217 complaints. The component named most often is pedals and linkages (1 mentions).
Is there a recall for 2012 Mercedes-Benz E350 brake problems?
No. NHTSA lists no brakes recall for the 2012 Mercedes-Benz E350, though it has 7 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2012 Mercedes-Benz E350 brake problems start?
Half of the complaints with a recorded mileage happened before about 160,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.