Have seen the many threads re: the MB E class but 2 weeks ago my 2009 SL550 (36K miles) had complete brake failure. I'm pretty easy going and don't care for drama but will say this was one if not the most terrifying situations I have been in. There was no soft stopping the car and it ended up drifting into a busy intersection. Gears locked. Depressing the brake with both feet standing up did not work until I jumped on them at least 5 times. Got it into reverse but with no brakes to stop it in reverse. My receipt states SBC Pressure pre load check "not ok" resulting in replacement of SBC Hydraulic unit. I wish I understood why this design flaw continues and why Customer Care placates and insults and treats this like it was a faulty light bulb. Will never drive the car again, will not wait until it happens again. All of this coming 1 month after dumping big $$$ to replace every piece and part of the suspension hydraulic system (sometimes twice) over two year period. Close to 10K total now. Neighbors want to know why my car is always being towed. Selling my kids MB. Couldn't live with myself if they weren't as fortunate as I was. So much for MB standing for reliability and stability.

 

An SBC brake failure is indeed a truly hair raising experience even for the most experienced of drivers. For those who have not experienced it, there is really no way to exaggerate just how helpless you are when it occurs. Saying that you're reduced to maybe 5 % of braking power is not at all an exaggeration. You HAVE to be lucky enough to not be at speed when it occurs. I feel your pain brother. Seems to me that an emergency backup air reservoir with a 2nd set of brake lines that would kick in much like an airbag and provide emergency braking capacity should have been a design element. Considering that the vehicle goes into limp mode, and the car downshifts whenever that Complete brake failure warning illuminates shows that the car knows it's in a catastophic state. Not adding such a backup just seems careless.

Also worth noting, everyone should make sure their batteries are in tip top shape. My SBC failure in my old SL55 was due to a low voltage situation caused by a malfunctioning TeleAid module. The module would keep trying to call out overnight continuously, thus resulting in a dead consumer battery every morning. Only by luck did I figure out what the problem was as I was sitting in the car on my laptop one evening when I saw the SOS light illuminate and noticed the call attempt. I'd decided to just disconnect the module the next weekend, but unfortunately didn't make it that far as the next morning I took off and then 3 blocks later had the complete brake failure due to insufficient voltage for the SBC pump to have properly pressurized the system. So word to the wise, when you get that Consumer Offline message, DON'T drive whilst the battery is recharging. STOP and make sure you've a healthy battery that is fully charged BEFORE driving.

 

. Thanks I️ had heard that about the batteries but had both batteries replaced less than a year ago.. you are spot on in saying NO ONE can really understand until it happens to them and apparently that includes MB. I’m a long time multi model owner and I️ thought they’d be on board for an amicable divorce but I️ suppose not.