I got the message when I got into the car this morning. Went ahead and started it and sure enough the brake pedal was just about useless.
Shut the car off, waited a minute and locked the door (while sitting in the car). Unlocked and started car up and no warning brakes back to normal....

Hooked up my obdII reader and no codes...

Could this be the limit of pedal depressions and the car warning me to replace the unit? Could something else have caused this? Should I flush fluid, have an indy reset counter and move on? Should I try to get dealer to replace?

 

Have MB pull your codes that you cannot retrieve I would start there

 

You will need someone with a star system to pull codes for the sbc system. I would get ready for your $1,000 repair!

 

ouch...

 

Are you still good for the ten year SBC warranty? Can't tell coz I don't think you're talking about the '86 190D.

 

I miss that old 190, zero technology.

Extended preservation of life warranty went out about 3 weeks ago..

You see this does not make sense to me. This SBC unit is clearly a wear item, but one that can intermittently go out and get you in serious trouble. I don't agree with the "let's check some codes and see if there's something else going on here" approach.
To me the braking system is the most important system in the car and the fact that it is inherently a faulty design that could get you killed AND they moved away from it tells me this is something THEY should replace out of pocket (MB NA not dealer).
The failure already occurred, the entire pump should be replaced YOU DON"T EFF AROUND WITH BRAKING!! This is life and death, if the system is inherently flawed, it should be replaced entirely at a moments notice of trouble.
It's not worth replacing components on an old pump only for it to fail again sooner than later with it's age.
Any other part of the car and I would fix it myself but on principle MB NA should be replacing these units indefinitely.
The dealer basically said to "just pay attention and watch your braking distances in case it happens again..."
WHAT!?
Get in an airplane with that kind of approach to safety and let me know how you feel about it.
Already contacted NA and they basically told me to take it to dealer and if pump needs replaced that they can't guarantee anything (other threads mention 10% discount max).

I'd take a bent floor mat over this any day.

 

ive read somewhere once that SBC is NOT actually a design flaw but was a clever idea that saved a lot of lives, (it was just replaced by a BETTER and MORE RELIABLE concept) just so happens that like everything else in this world. it will break sooner or later. My old 211 was an 02, first gen, first of its kind. had about 160K on the clock and never had any issues with the SBC as far as I know. although, I admit that this worries me, which is why I traded it.

the "limit of depressions" you've read is a MYTH! best to do is go to a dealer and get the car scanned. goodluck mate!

 

You see I agree with you in that it actually is a clever system when it works. Eliminates abs pedal feedback, can send braking to the necessary wheels faster than the driver can think.
And indeed nothing last forever and I expect it to fail.
ITS THE WAY IT FAILS! That is the issue and unless prematurely replaced it will fail in the most unexpected way.

Also: Im curious as to why mercedes abandoned SBC so rapidly considering most of their part development cycles. Perhaps it had something to do with the russian roulette failure procedure. The system they returned to? You guessed it, standard hydraulics, they really had to modify the firewall to get the booster to fit. Must have been in a hurry

 

what year model is your car and how long have you had it for?

 

All braking systems are flawed, at some point a component will fail, pads will wear out, lines will rust out. I don't really follow why MB or any manufacturer should warranty the whole system forever. I think the only issue here is the cost involved. On other manufactures, master cylinders and brake boosters will fail and there's no lifetime coverage from the manufacturer and none is expected, when those go, you will also have minimum braking. Cars aren't designed to the same level of reliability as airplanes, thank goodness otherwise they would probably cost way more.

 

try to look at it this way. imagine your car was a civic, you start the car, you drive off at 80kph and you step on the brake and it goes straight through the floor coz the master cylinder failed. now go back to your experience this morning, you got into your merc, you started the car and it gave you a warning. just be thankful for that.

FWIW, the reason I asked what year your car is and how long youve had it is because repairs there will cost you about a grand. whats that compared to a 10 yr lifespan? now stop whining about your car coz it just saved your life!

 

Yes. I do not disagree with this in any way. What you are ignoring is that failures in a standard hydraulic system are not only rare, but when they do occur it is simply do to negligence on the owners behalf. You can VISUALLY inspect these items for wear and when/if they do fail I promise it is nothing like what you will experience in a car with a remote control for a brake pedal. There is always residual fluid in most of the calipers you will gradually lose pressure. I have a CDL and was driving a 24 ft straight truck when the air brakes went out. This is a vehicle that weighed probably around 5 or 6 times that of the merc when this happened. Even in an air brake system with air blowing out of the cylinders like a baloon I had ample time and braking force remaining to safely pull over. It wasn't 100%>2% INSTANTLY. Trust me, nothing can fail as fast and as unexpected as an SBC equipped car, there are no indications. Like I said, the car now has full pressure again!! Who knows when it could happen again but NOW I know it needs to be replaced, AFTER it could have caused an accident. zero wear indication. ZERO

^^ As funny as it sounds I actually appreciate it happening in the driveway, it's almost as if the car was looking out for me.
Unfortunately others were not as lucky and I have heard of stories where there were very near misses. Also there are people who had it happen once and never again. So it's like, do I drop 2k when I don't need to as preventative maintenance? I think so but again zero warning, zero indications of wear, and zero indication of if it will happen again. At least when a regular brake component fails you can visually inspect it.

ANYWHO I have had a lot of crazy things happen in a car, blow outs, wheel come off, control arms snap, cracked rim, power steering pump failure, clutch master fail, clutch slave fail, (had to pick up the clutch pedal with my hand to shift gears for 40 miles) etc etc over the years for many different reasons but this was by far the most shocking thing I have ever experienced in a road car.
You may not believe me, but boy the day it happens to you look out!!




ps: from another thread... "The Wife and I have gone over how to stop the car by downshifting, right foot on main brakes, left foot on e-brake with left hand holding e-brake release. Hoping it never comes to that."
^^ seriously

 

I had a master cylinder fail on me. No way to inspect it for wear. The seals that are inside the cylinder failed, there was no fluid leak so no warning light on the dash, pedal just went to the floor and was hard to stop. I knew it was the master cylinder because I went to the forum for that car and they said when that happens, that's typically the master cylinder so it's somewhat common for that to fail and people on that forum weren't up in arms about it. Maybe because the master cylinder was a $50 part instead of an MB pump being $800-$900.

 

more like $2000 if you go to the dealer to get it replaced. I suggest to but the part and have and indy shop experienced with MB to install it.

 

Master cylinders can and do fail internally. Sometimes you can catch a master cylinder failing early by looking for leaks or stains. If it does NOT leak externally and only internally guess what? Your not losing fluid so you still have brakes particularly if you pump them. I have also had to do this and again nothing like the ON/OFF switch like the SBC failing. Not even close. I would take a failed master cylinder any day, which by the way is an actual mechanical failure that typically stays failed unlike the SBC which sort of picks a random time to fail, but then work fine for days, weeks, years... And yes price does come into the equation of course.
MB NA extended the warranty on the gas tanks issue to 15 years....
So clearly your brakes randomly failing at 80 is not worth that extra 5 years but a leaky fuel tank is.
I've driven (in an emergency) with a MASSIVE leak coming from a gas tank and again from a fuel hose leading to external pump. Both occasions I was fine, there was no fire and I made it home safely to repair.
The same can not be said for SBC.

I hope this does not happen to any of you, but if it does I promise you will have a change of heart.

 

Yes it was somewhere between 2 and 2.5k.
I think I will see if local merc indy will let me use star and I will replace it. I would love to take one of these apart as there was some mention in another thread (http://www.benzworld.org/forums/w211...ne-wild-4.html) Where there is a mention of a potential oversight on the internal shutoff valve:

Yikes....

I am considering buying the pump myself and seeing if the local merc indy will either let me install or help. Unfortunately... no warranty so you save but potentially lose..

Again, this isn't a master cylinder failing (which is rare and usually caught before hand with proper service by DIY like me) this isn't a caliper seizing, this isn't a brake line rupturing, this isn't completely worn pads/rotors, This is your entire braking system GONE. It would be like all of the above happening at once, only you have been replacing the fluid/pads/rotors ON TIME.

 

There's a few threads floating around out there about this. I think huskerparts.com probably has the lowest price for a reman pump, around $800 or so. Someone else also asked their local MB dealer and while the dealer was quoting close to $2k for a new part, they said they would put in the reman part as long as it was an MB part so they would only have to pay for labor.

As for the master cylinder failure, I'd say braking was about 10-20% of normal. I was just driving normally when it happened and when I went to slow down, it didn't slow down, I had to plant my foot just to slow down. Didn't hit anything though. Others have mentioned that when the SBC fails, you get about 10% of the normal amount of braking.

SBC was one of the reasons I decided to get a 2007+ E350 instead. Balance shafts made that 2008+

 

I have a 2003 E320 and my red brake light has been on for about 2k miles, I had it hooked up to a star diagnostic and it thru the pressure reservoir failure code...now I called MBUSA they said take it to a dealer and let them inspect it...ofc after $115 car wash they said the entire SBC pump needs to be replaced but I have not had any breaking failure..it just feels like the brakes are engaged sometimes when the pedal is not being pressed. I then got estimates from an MB Indy and they wanted 1650 to replace the whole pump vs 2100 at the $tealership...So what did I do ? Ordered the Bosch pressure reservoir for $150 and had it installed for 100 dollars and boom red light gone. MBUSA should extend the SBC warranty tho, my car had less than 100k miles and that's normally the threshold for when they start acting up, I felt like I was being punished for being a low mileage car since corprate would not replace mine cause it was after 10 years.

 

As stated elsewhere, we all are aware that braking systems can and do fail due to a variety of factors. What makes the SBC system unique is that the failure is due to a pre-programmed/predetermined service threshold. As several owners have stated, it results in no braking power what so ever. I have attached the MB document.

Please file your complaint with NHTSA. The thread is a sticky at the beginning of this forum.

John

 

SBC sucks! Can't stand driving cars with it, pedal just starts pulsating out of no where, like chill. HAHA. Really though, if you go to a dealership and it says threshold met, program sbc unit, expect within the next six months it's going to take a dump on you.

On another note I have never seen something so expensive like sbc have countless repairs done to it. My personal opinion is sbc is the worst design ever. The lords in Deutschland figured that out as well hence them running away from it after 2007 I think it was, couple that with the fact 230's/219's/211's all have sbc, so its not just us, 230's are the only model that still use it. Anything after 07 related to brake system control units never have issues. And i mean never, wheels speed sensors here and there and other little piddly things. Pads rotors and a flush are the only means of "brake system maintenance" now on MB's.

 

I'm curious if someone has or could figure out a way to have a normally "closed" shutoff valve when remanning an SBC unit? Seems like it's not only worth investigation but someone could probably start a small business selling remanned units with said valve. Then at least your failure would give much more in the way of actual hydraulic braking.

 

You want MB to warranty their braking system forever or until you sell it. And now you think that maybe some small business will want to make a modification to a braking system? How much more would you be willing to pay over the $800-$900 cost of a reman unit? I don't think any small business would be able to afford the liability insurance.

 

I don't expect MB to warranty the SBC forever. What I expect is a software upgrade to warn the driver that the "service threshold" is within X number of activations of being reached so the unit can be changed.

A death is going to occur because of this system ending braking power without prior warning and then the lawyers will have a field day.

John

 

I thought it already did that, just not the way you expect. Remember, the pump is mechanical, I believe the current systems guesses as to how long it will last and then displays a warning message that you should get the pump replaced. It may last a while longer or it may fail before that message pops up. So now you want a warning message that's going to tell you that there's going to be a warning message soon? I believe when it fails, you still have some braking power, just a minimal amount. Probably bad if you happen to be tailgating at the time or if some pedestrian decides to jump onto the street at the exact same moment, but you should be able to compensate in normal driving. But they must just chalk all that up to an acceptable business risk. I think people are really upset about the cost, not the safety issue. But file a complaint with the NHTSA, maybe something will be done, it took a while for MB to come up with a warranty for the gas tank.

 

wish there's a way to bypass SBC...