Hi, this is my first post on MBWorld. As my username suggests, though I love my 2013 E350 Sport Sedan, it has given me a few costly headaches, in at least two cases due to incompetence of MB dealership mechanics. My latest headache almost cost me or someone else my life: my brakes failed at 65 mph, as I was trying to slow down to 45 to round a curve between freeways. Luckily, I turned on to a slightly uphill climb, allowing me to slow the car down on the rough shoulder, hit the parking brake, and shift it into park. Had this occurred 30 seconds later, I would have started down 4 miles of winding 6% grade at top speed, where the speed limit is 55 mph. In commuter traffic.

The problem was the result of a mechanic at the Mercedes dealership (to remain unnamed) failing to tighten the brake fluid bleeder during normal servicing a few days prior. My AAA tow truck driver caught it, and MB admitted it. It was completely empty. Human error that could have been fatal. What's equally concerning is that I received zero warning that my brake fluid was low or out while driving. It was only later, when I was trying to shift the car from Park into Neutral (to get it on to the tow truck) that I got the Brake Fluid Low/out warning light/message on the dashboard. (As you know, if your brakes don't function, the car won't let you shift out of Park.) We had to fill it with brake fluid and bleed it in order to shift it. By that time, there was no way in hell I was going to drive that car. I'm still shaken by the incident because I don't know whether my warning systems are reliable.

Is there a reasonable explanation for the brake fluid warning light not coming on? Has anyone heard of this happening to another driver before? I haven't found anything on any forum so far. Thanks in advance. Drive safely, y'all.

 

Hopefully the dealership will correct or if you have a major concern about the dealership call MB Corporate or district/regional manager and request that it be corrected at another LOCAL MB dealership. As for the warning light, did you check the area surrounding the master cylinder reservoir and see of the sensor if installed could be damaged, cracked, broke, wiring torn etc... Do you remember getting the warning at start up...the self test feature? If there was a major brake system failure, like low fluid it should stay on after engine start. Also possible that the original mechanic COULD HAVE disconnected the sensor, whatever reason, maybe to gain access to another component and forgot to re connect. Again the system should have triggered that as a faulty since there was no signal source.

By no means am I endorsing the dealership and mechanics screw up especially with a big ticket safety item like brakes but this could be a starting point to how it happened and why. Trust me I work in aviation and safety is stressed every minute. We have classes on safety, fatigue and the "Swiss Cheese" alignment of holes in the cheese to align and cause the incident. Different career field but same concept. Could be as simple as head not in the game, distraction, etc....

 

That is not a good situation to be in when your brakes are not working properly. Did you have a spongy feel in the brake pedal prior to getting on the highway? It should have been apparent something was not right when braking at slow speed.

 

Hi, thanks for the detailed advice. Lots to investigate, based on that information! I will see what I can find out.
EDIT: I meant this as a reply to @2011E350 .

 

 

Sorry to hear about that nightmare, thankfully you're alright. I recently had my brakes flushed at the dealer's and I just noticed they refilled reservoir up to the minimum mark! I guess I'm OK, but I'll bring it to their attention. What's wrong with these dealerships?

 

Trying to save .05 cents on the bottom line but probably stepping over $100 dollar bills in the process. I always tell them to the MAX. Last year I had a Alamo rental that I stopped in the dealer and asked them to top to max....I told them Alamo may provide sloppy maintenance but while I am in command of this vehicle it is going to be topped off correctly. Dealer agreed with me and gave me a courtesy top off. I also evaluate my rental needs, if I am going for a day/local rental I don't even look at the hood. If its a long term, and or Cross Country I check everything. get Fluids topped off. I once refused upgrade because it had about 3% oil life left. This was DFW and a road trip to Maine found normal class rental with about 60% still a little close for a long term road trip but returned 4500 miles later and down to about 8% Told them do not even pass go, report directly to the oil change bay!

The other part is most people trust what dealerships do, they say oil was changed and fluids topped off that's good enough for soccer moms who need to get restless screaming curtain climbers to Spencer and Chelsea can get to Soccer practice so Mama can meet Suzie and Babs at Applebee's for Happy hour!!
Again no offense intended....if you are a soccer mom and if your name is Babs; Suzie, Spencer, and Chelsea...…...and are offended..... Get a life, take it for the joke it is meant to be and get your homework and chores done......And for God's sakes...step into a rain locker (Shower).,....you just spent one hour rolling around in the mud, grass, dirt, dust...….You smell!!!

 

OP, sorry to hear about that ordeal. What a nightmare - lucky no one was injured. They better take care of you.

If the brakes were working alright in the few days up to that moment, I wonder if it was a sudden loss of brake fluid at that moment. Do you recall seeing any fluid in garage or parking spots? Any signs of soft brakes prior to that moment?

 

Holy crap. I have nothing constructive to add to this except that I'm glad everything ended well. I don't even know what I would demand of the dealership if they screwed the pooch this badly with me.

 

Glad there were no injuries but I can totally understand the emotional toll. I have no previous or current knowledge of the dealership involved and probably better I don't. Yes I understand the frustration but sounds like a isolated case and bad day. Definitely address the concerns with the Service Manager and GM at minimum they should correct initial problem. re service fluid and if it got that low there COULD be trapped air in the system. I would demand a total brake flush and bleed out to get 1. Fresh new fluid and 2 get any residual trapped air removed. At their cost obviously and demand a different mechanic. Also demand a loaner. I would hope that they covered the tow truck bill if not then demand that. If they don't agree then that's what district/regional managers and VP's come in and as last resort social media and attorneys. One word of caution especially social media.....make sure the events are true and not embellished. There have been slander lawsuits by businesses against reviewers for unfair comments, reviews etc.... I would extremely hope that it wouldn't get that far but you get the idea.

 

as for low fluid warning you would have to pressed the brakes multiple times to push the fluid out the leaking bleeder.

It only comes on when reservoir level is low not when you have a leak.

So yes it would have taken a while for light to come on.

Way to confirm is once you filled reservoir did light go off?

 

He mentioned that it was completely after the incident, and the light still hadn't come on. Is there purpose to even having a light if it doesn't illuminate until LONG after the brake fluid is dry?

 

I still say low level sensor disconnected and forgot to re connect. Doesn't change the outcome but if there is no signal source to the low fluid sensor how would it illuminate the brake light on the I/P?

 

I think OP stated that the Brake Fluid Low/out warning light/message on the dashboard came on when car was started to shift to move on tow truck. If sensor was never reconnected by mechanic, then OP or tow truck driver would have had to connect it before tow.

 

You would not have completely lost your brakes due to a loose bleeder. You would have lost half of your braking capability because for this very reason modern car braking systems are dual circuit. Not good certainly but you would not have been without any braking capability.

 

Much in the same way that you don't really lose braking when you lose ABS. Yes the anti skid feature is lost but you still have normal braking. expect increased stopping distances of course and you will have to manually make sure you don't skid.