I am in the United States and I have experienced the same ridiculous run-around by Mercedes, but as I dig more into the issues it appears that Mercedes may be covering-up some things.
In the United States, Mercedes's official reports to the US Government Vehicle Safety Agency (NHTSA) appear conflicting. Mercedes specifies in its initial filings that it was instructing the dealerships to perform the testing of braking systems of the vehicles only once, stating that: “The test may only be performed once and in full without interruption.”
My vehicle failed the testing and it has been at the dealership for over two months. Yet a few weeks ago, however, the dealer told me that Mercedes instructed them to suddenly re-test the vehicles with “reportedly” the "same test" and surprisingly, like you, I am told the car passed. So now, miraculously, the car that they towed in due to failing the brake safety testing is suddenly ok to drive for "up to 2 years", despite no repairs having been made. I found their statement of "up to 2 year" further worrying as why the time frame if there is suddenly no issue with my car? Furthermore, they certainly don't know much driving we were intending, nor the conditions that we may otherwise be using this vehicle in the interim (such as would we be constantly be going up and down hills and mountains). If for example, we drive it often in more demanding conditions it would seemingly put considerably more strain on the braking system than a vehicle that is used little or driven in flat areas.
They required me to return the loaner, but I have not picked up my vehicle, as I stated I did not feel comfortable and wanted to discuss matters with Mercedes Corporate. Mercedes Corporate reportedly opened a case related to my inquiry yet nobody was calling me for weeks as it appeared they were delaying responding in hopes that I may not pursue my inquiry. After waiting what was probably a week or two I then I kept calling and spoke to different people. I did get conflicting positions, some say do not drive the vehicle if it failed at all, while when their representative that was officially assigned to my complaint did finally call me back he emphasised that Mercedes positon was that if it passed the second time then it is ok to drive and Mercedes would not continue to store the car nor provide a loaner in the interim, even though Mercedes indicated that my brake booster would need to be replaced. I then tried going higher up the chain at Mercedes Corporate but they have simply not been helpful. In the interim, while the car is still at their dealership I have also had to rent a vehicle, paid with my own money, and Mercedes does not want to reimburse me for those interim expenses.
Of course, all this does not sit well... as I too am not willing to risk my family in a vehicle that failed any braking test, especially a comprehensive test of the integrity of the braking system for a vehicle involved in an official... and rather extreme... STOP DRIVE NOTIFICATION. And especially where I am told that they don't have the replacement parts available but that my vehicle will eventually need the part replaced.
It just does not makes sense that Mercedes failed my vehicle, towed it to the dealership, left it sitting for over a month as I was told it was “not safe to drive”, to only now tell me that it is ok to drive with no repairs being made…this is not comforting nor convincing! When I asked them to just replace the problem parts, they tell me that the parts are simply not available, and Mercedes is working to re-design them for all the cars under the recall notice. I know that the rest of my braking system is in top condition as within the past few months (before any notice of the recall) I literally had all the brake pads and rotors replaced with high-quality / OEM parts and the brake fluid was also flushed. Therefore they cannot blame any issues with braking on me or maintenance. What I have learned is that the brake booster is faulty in design and can thus fail, where because the failure involves the potential loss of braking, the STOP DRIVE NOTIFICATION was issued.
When my vehicle was initially towed into the Mercedes dealership, I was told that when they tested my vehicle it was one of the worst ones that the dealership had tested. They told me clearly that I must not drive it and Mercedes would provide a loaner vehicle. Yet, when they later told me that it passed the “same test” when they were instructed by Mercedes to test it again, I asked how could it suddenly pass if they made no repairs. They had no answer, only that Mercedes told them to retest the vehicles that had failed and if it passed the second time to then return the vehicle to the owner.
This is where I found the original post to be so very telling. Where you mentioned that Mercedes representatives in Australia told you:
"Mercedes had changed the 'parameters' of the brake test and now my car has passed"
And where you later followed up with Mercedes and they could not clearly explain things regarding the testing and if the original parameters were wrong why didn't every vehicle fail.
The more I have recently dug into the issue and contacted people that I know in the industry, the more troubling things appear. I have learned that Mercedes ultimately reported to the U.S. Government that all of the recall notice vehicles are believed to be defective. In the U.S. that is nearly 300,000 vehicles, and worldwide approximately a million vehicles. Mercedes’s official filings with the US Government represent that amongst the nearly 300,000 vehicles involved in the recall notice Mercedes reports:
“Estimated percentage with defect: 100 %”
In looking at these factors, it seems rather obvious to me that it is likely Mercedes had a huge problem to deal with as the logistics of re-designing and facilitating replacement of parts on a million vehicles. This certainly will take considerable time to address, meanwhile, beyond the testing expenses it faces ongoing costs with the loaner vehicles and storage of the defective vehicles at the dealers. Further considering the ongoing worldwide supply chain issues these days, the problem likely has no clear timeline, and while Mercedes is facing ever-increasing mountains of expenses.
I suspect that so many vehicles were failing the standardized testing that Mercedes was using for the booster, that these expenses were getting out of control and it had to find a way to buy some more time, meanwhile it had no clear indication as to when such replacement parts and repairs may be available.
Speaking with friends in the industry, the belief is that while those interim costs are accumulating rapidly they likely tried to figure out a way to get many failing vehicles back to the owners to reduce expenses. With the claimed re-test and with your understanding of their convenient changing of parameters this now makes much more sense!
However, it appears that they are not telling owners, nor the U.S. Department of Transportation, of their changing the parameters to apparently find a way to “report” a pass of more vehicles. This may also be due to reporting requirements where they may have to report the number of vehicles that failed to various governments and if the numbers are too high some governments may issue more extreme measures.
For example, years ago in the United States, Nissan Motors had a problem with defective Vans that they were selling, which had serious design flaws that caused many of these vans to suddenly catch on fire mainly in the engine bay area. With the U.S. Government investigating claims and pressuring action, Nissan announced a recall, a recall which did not fix the problem but bought time for Nissan. Then as time passed reports of more fires kept coming in and the government saw that the issue continued to persist, it then pressured Nissan to take more action which resulted in a second recall. In the same manner that second recall bought time for Nissan as they knew internally that the recall would not work. (I spoke with friends who worked at Nissan and they told me the company knew the problem could not be reasonably fixed due to many problem design factors, but that the top people at the company hoped they could pacify the U.S. government with the ‘appearance of repairs being made” / a bandage approaches that essentially did not address the actual more serious problem but appeared to be something to the government investigators. Over and over again this happened…for a third and fourth recall and thus after delaying properly addressing the problem for many years and with continuing fires occurring… Nissan was forced to announce a buy-back of all approximately 33,000 affected vans. However, in delaying matters for many years Nissan effectively bought time and in several ways they also reduced the expenses. When they were ultimately forced to announce the buy-back of the 33,000 defective vehicles the remaining vehicles were much older and thus the buy-back offers represented a much lower overall amount.
I am not saying that the Mercedes issue is the same, as catching on fire for Nissan vans is different than brake booster failures in Mercedes vehicles. However to my understanding (based on research), Nissan wasn’t even forced to announce a STOP DRIVE NOTIFICATION with the recalls. Also one would think that, as with the Nissan vehicles, if the vehicle started to catch on fire the occupants would in most cases likely pull over and be able to rapidly get out of the car before the fires became worse.
Yet looking a the Mercedes issue, if the brakes were to fail, especially at high speed, what could you do? You can’t simply and reasonably get out of the car….until it stops that is. The problem is how to stop the vehicle, without causing damages, injuries, or deaths?
As I see it, when a vehicle design shows any substantive failures in safety testing, especially in regards to the braking system, this is where the company, in this case Mercedes, needs to take the most cautious approach and not the financial, what they call the "bean counter" approach (to possibly save money). It seems to me that Mercedes was possibly trying to reduce the ongoing mounting costs related to those vehicles, until they could get the parts redesigned, manufactured, sent to the dealers, and hopefully get those cars repaired.
I understand that this type of risk adjustment (bean counter approach) is a calculation where automakers are willing to accept certain “failure rates”, and where “buying time” with delays may save more money in the long run than the damages they may face from component failures (accidents, etc. or those fewer instances that may result in long term lawsuits that automakers tend to aggressively fight to avoid legal findings of responsibility. Mercedes probably estimated that it would not have so many vehicles fail its standardized testing of the braking system and with the mounting costs I would not be surprised if the higher-ups in the corporation likely felt that they needed to find a way to buy more time and reduce expenses…in hopes that the issues would not get worse. But the issue, at its foundation, is so serious that Mercedes was essentially put in a position that they had to issue what I understand is a very rare STOP DRIVE NOTIFICATION. Meanwhile, a million or so vehicles are out there where the brakes could fail due to design flaws and nobody knows how many accidents could occur or have occurred, as many accidents likely don’t have the specific faulty brake booster part subsequently inspected. Furthermore, with rust as one of the issues involved in contributing to the problem, the efficiency of the brake booster may actually be degrading over time, the parts weakening, and the owner just doesn’t know…until it perhaps it suddenly fails dramatically.
With Mercedes admitting that the “Estimated percentage with defect: 100 %” and where the testing of my vehicle showed initial failures in the system and serious concerns as to the potential integrity of my vehicle's braking system, no risk is acceptable to me and my family without available repairs. Simply put, the brakes are one of the, if not the, most important safety component of a vehicle! I believe Mercedes is being irresponsible in returning any vehicles to owners which failed any brake efficiency testing, and that they need to be held properly accountable!
Reviewing what Mercedes reported to the U.S Government’s vehicle safety agency (NHTSA) here are various quotes from those filings:
ISSUE:
Mercedes-Benz AG (“MBAG”), the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year (“MY”) 2006-2012 ML, GL (W164/X164 platform) and R-Class (R251 platform) vehicles, the function of the brake booster might be affected due to advanced corrosion in the joint area of its housing. After extended time in the field and in conjunction with prolonged water exposure, this corrosion might lead to a vacuum leak at the brake booster. If this were to occur, the brake force support might be reduced, leading to an increase in the brake pedal forces required to decelerate the vehicle, and/or increased stopping distances are possible. Additionally, in rare cases of very severe corrosion, it might be possible for a particularly strong or hard brake application to cause mechanical damage in the brake booster, whereby the connection between brake pedal and brake system would fail. In such a very rare case, it would not be possible to decelerate the vehicle via the brake pedal. The risk of a crash or injury would be increased. The function of the parking brake is not affected by this issue. Before the issue occurs, the driver might notice a change in the brake pedal feel and/or hissing/airflow noises when applying the brake pedal.
WHAT WE’RE DOING:
MBUSA will conduct a voluntary recall. An authorized Mercedes-Benz dealer will remove the rubber sleeve from the brake booster housing, check the brake booster on the affected vehicles and, depending on the result of this inspection, replace as necessary. Until the inspection process is completed, affected customers will be instructed by the MBUSA recall owner notification letter to stop driving their vehicles at the time of recall launch.
POPULATION: (in the United States)
Number of potentially involved: 292,287
Estimated percentage with defect: 100 %
DESCRIPTION OF SAFETY RISK:
After extended time in the field and in conjunction with significant water exposure, this corrosion might lead to a leakage of the brake booster. In this case, the brake force support might be reduced, leading to an increase in the brake pedal forces required to decelerate the vehicle and/or to potentially increased stopping distance. Additionally, in rare cases of very severe corrosion, it might be possible for a particularly strong or hard braking maneuver to cause mechanical damage in the brake booster, whereby the connection between brake pedal and brake system would fail. In such a very rare case, it would not be possible to decelerate the vehicle via the service brake. Thus, the risk of a crash or injury would be increased. The function of the foot parking brake is not affected by this issue.
What happens if the dealer determines repairs aren’t necessary now but Owners experience concerns related to the recall in the future? Are Owners responsible for diagnostic fees/repair costs?
a. Any future owner concerns will be evaluated on an individual basis. Extensive analyses were conducted by Mercedes-Benz AG. Based on these analyses, a test method was developed for the workshops which, among other aspects, ensures the functionality of the brake booster by usage of diagnostic-supported test routines. If the dealer determines based on the inspection that the brake booster does not need to be replaced at this time but the owner experiences recall-related concerns in the future, a re-inspection may be carried out within 2 years to ensure the functionality of the brake booster. Parts and labor associated with the recall are free of charge to the customer.
What types of repairs or replacements part(s) are needed?
a. At this time the recall has not been launched. When the recall is launched and instructions have been provided to authorized Mercedes-Benz dealerships, affected vehicles will be inspected as a first step. After this inspection, the vehicle will be given 1 of 3 statuses.
i. Inspected with no corrosion: The rubber sleeve will be removed. The vehicle can be driven with no further action or follow-up.
ii. Inspected with advanced corrosion found: A brake efficacy test will be performed. A passed test ensures the tested brake booster can continue to be used and the vehicle driven up to a maximum of 2 years. A new notice will be provided at a later date to bring the vehicle to an authorized Mercedes-Benz dealership for further inspection and potential replacement of the brake booster.
iii. Inspected with advanced corrosion and brake efficacy test does not pass: The vehicle will require the brake booster housing to be replaced when parts are available. Until then, the vehicle MUST NOT be driven.
The dealer instruction initially stated:
Check brake booster with XENTRY/DAS.
To do this, select the menu item "Main groups – Control units - Chassis – ESP-Electronic Stability Program – Complete list of guided tests – Braking power".
Then follow the user guidance in XENTRY/DAS Diagnosis.
Print out the brake force "event log" after the test and store to a local HDD/computer storage location.
ENTRY/DAS check not passed: Close campaign with claim. See Launch NCU FAQ for mobility solution options to offer to the customer until parts are available and the part can be exchanged. Do not provide customer Certificate of Passed Initial Diagnostic Brake Test.
XENTRY/DAS check passed: Continue.
The test may only be performed once and in full without interruption. Do not perform any unnecessary braking procedures (maximum full-stop braking) before the test.
However, Mercedes later modified the instructions as follows but make no reference to a different test:
Check brake booster with XENTRY/DAS.
To do this, select the menu item "Main groups – Control units - Chassis – ESP-Electronic Stability Program – Complete list of guided tests – Braking power".
Then follow the user guidance in XENTRY/DAS Diagnosis.
Print out the brake force "event log" after the test and store to a local HDD/computer storage location.
XENTRY/DAS test not passed: Please perform this test again. Only perform this test twice.
XENTRY/DAS test passed: Continue with operation step 2
If the XENTRY/DAS test was not passed the first time, you must perform a second XENTRY/DAS test. If this second test is now passed, continue with the operation step 2 of scope of testing B. IMPORTANT: Only perform the second test if the first XENTRY/DAS test was not passed. The second test must be invoiced using operation number 02-0245 or 02-0246.
XENTRY/DAS test of the second test not passed: Close campaign with claim. See Launch NCU FAQ for mobility solution options to offer to the customer until parts are available and the part can be exchanged. Do not provide customer Certificate of Passed Initial Diagnostic Brake Test.
XENTRY/DAS test of the second test passed: Continue with operation step 2.
My final thoughts:
For Mercedes to tell me that the vehicle is unsafe after first running the brake system testing, which as Mercedes represents as:
“…a test method was developed for the workshops which, among other aspects, ensures the functionality of the brake booster by usage of diagnostic-supported test routines.”
…and to tow it to the dealer and store it for weeks, is clear enough for me that there is a serious problem suspected or potential for brake failure with my vehicle.
For Mercedes to also inform the U.S. Government that the defect affects 100% of the vehicles produced in these various models and years of production, is clear that the full population of these vehicles will eventually need the parts replaced, and with approximately a million vehicles worldwide this is certainly a huge problem for Mercedes. With my family's car failing the first comprehensive testing, and where it was determined to be so serious that they towed the vehicle to the dealer, told me it was unsafe and that they would store it until repaired....in my mind this automatically warns me that it has safety concerns. I can't unsee those facts, and as a result, my family and I feel that we cannot comfortably drive it. I also wonder how many other vehicles were tested (once or twice) and had failed the testing but were returned to the owners, since replacement parts are simply not available and where testing results may be conflicting or have perhaps conveniently changed? At what point is there risk or not in driving these vehicles, and is Mercedes perhaps trying to limit the number of vehicles that tested with failures in its reports to the various governments? Meanwhile, I see no other reasonable alternative but to continue to pursue Mercedes to take a more responsible and transparent position in addressing these issues!
