Nevin

I have a 2005 E500 that has developed a frightening glitch that MB can not seem to eliminate. Every so often as you drive the car, the brake system makes a fairly loud groaning sound and the brake pedal vibrates and adjusts its position. This can be quite a thrill when the pedal vibrates and drops an inch or so as you are applying the brakes. (Natural reaction is to panic as it feels like you are chasing a moving pedal and end up braking too hard when the pedal finally stops moving.)

This glitch has occurred at startup, while stopped at a traffic signal, while pulling into a parking space, during mild as well as moderate braking and while just rolling down the road.

MB has had the car for over three months out of the last six and has replaced the brake system controller as well as the complete pedal assembly after the factory rep drove the car.

The problem is worse than ever and MB's latest response is that it is normal and there is nothing to fix. I own another E and an SL which do not exhibit this behavior, but my request to add this normal feature to them was not viewed as humorous.

So tell me...

Is this normal or is MB so comfortable now that it doesn't mind blowing off a customer who has purchased 5 MB vehicles in the past 5 years?

PlayboyDiddy

From what you stated, that does not seem normal to me.

When I first bought my E class, the brake pedal would vibrate a little and make a small sound, but did not move downward like your car does. The dealer made an adjustment and it is less noticeable.

I would not settle for what they are telling you. It seems like if they can't figure out the problem, they just state it is normal. They do the same thing when people complain about the brake squeak many of our cars make.

Your problem is definitely a safety issue that should be addressed and fixed. I would keep bringing it in and if they still do not fix the problem, consult an attorney.

alewifebp

That is not normal at all, and the dealer should really not let you drive your car. Sounds like some real big problem with SBC. I would consider that a significant safety issue.

Hopefully konigstiger will weigh in on this issue, as he knows the proper people to contact.

MotorWerkz

if you read the manual in page 82-83, you'll find that the noise and vibration is caused by the SBC pump, it seems normal.

mine also do that, although I find it annoying, I try to ignore it.

here's what I found in the manual book:


The SBC brake system is automatically activated if you:
- unlock the vehicle using the key or the keyless go system
- open the driver's or front passenger door
- switch on the ignition
- press the keyless go button on the selector lever once when using the keyless go
- depress the brake pedal
- release the parking brake.

dorfman24

The groaning and vibration you describe is normal for a W211. As you may know, the W211 has a brake-by-wire SBC system. Upon start-up and when necessary the brake pump will run (and cause the vibration). I get this every five pumps of the pedal or so. What is NOT normal is the pedal moving. Mine does not do this and MB should fix that. But don't worry if they can't fix the groaning and vibration (they can dampen it, but not eliminate it). When you experience it, just remind your self that you have the most advanced braking system on the road.

KosherBenz

sbc ftw!

Barry45RPM

I had SBC. The motor/pump sounds are normal, but I don't remember the pedal dropping or raising an inch. Outside of the Humming of the pump motor, I never felt that the brakes/pedal were any different than any other car of similar size & weight.

Since describing something on line is harder to understand than sitting in the car & experiencing it, I'd take it to another dealership & let them try to duplicate the sensation. Then you can let it rest or push for a repair.

Nevin

Thanks for the input...

The motor/pump sounds in my other two cars with SBC are barely perceptible to the driver. The sounds in the E500 can be heard by backseat passengers over conversation or music.

It is not so easy to take the car to another dealership out here where the dealerships are 100+ miles away from each other.

The dealership and Mercedes have had the car for over 100 days trying to fix this before they deemed it normal, how much more time do you suggest I give them?

Barry45RPM

Doe it seem normal to you? Do you feel safe? Can you put it behind you and forget about it?

YOU are the final inspector.

cyclerider

You must live out here in the wild west.

Nevin

Nobody here at the company will drive the car, it has scared the bejeebers out of everyone at least once.

We loaned it to our accountant when his BMW was in for service. He brought it back with a thanks, but no thanks. He said it was possessed.

Imagine being in stop and go traffic and the brake pedal moving up and down during and between stops. One time the car stops fine, fifteen seconds later with the same pressure on the pedal, the car doesn't slow down at all. You push harder and the pedal catches and stands the car on its nose.

No, I cannot put it behind me and live with it.

I just wanted to verify beyond the two cars with SBC I have that do not do this that it was not normal.

I guess my other alternative is to take the other cars in and have them add this normal feature to them.

Just for reference...

2003 S55
2003 SL500
2004 CLK320
2005 E500 (Christine)
2006 E350

MBZman

Nevin, your car is a lemon. If you leased it, look into the lemon law for your state. If you bought it any reputable dealer should work with you to roll you into a new car thus avoiding the headache that comes with implementing the lemon law.

konigstiger

Check your PM.

Joshua

Nevin, I had exactly this problem but not to the extent of the brake pedal dipping. Mine's an E320. Thanks to Dan from this forum I contacted my dealer who is taking my car in to insert a pulsation damper to alleviate (but not totally get rid of) the problem.

Its the SBC actuator / pump kicking in to maintain system hydraulic pressure due to the SBC system compensating for variable driver braking pressures on the pedal...i think !!

Good luck. I know how annoying this is and thought of getting rid of the car after owning it for just one week. I may still go ahead at great $ loss and get rid of it if it has not imporved after the mod.

bigassgun

Hey dude get a new SBC pump for your car asap...just like what i did

But one thing about them dampening the sound...it will almost never fail to come back after some time

brabus2ner

i have the same problem too. As i ask my adviser they say that it is normal to have that kind of vibrating due to the hydrolic brake. But if you really feel the brake, it is not as responsive as the C class brake. Futhermore, if the brake is very hot some time it need more room to make it a complete stop. I also confuse that should i ask them to change SBC pum or not. Another question is that is the SBC pum is under warranty, because as i know that the brakes is not under warranty, and it is under wear and tear.

konigstiger

Brakes are wear and tear however, depending on the dealership’s cooperation are covered for replacement throughout the first 12,000 miles or 12 months (whichever comes first) of ownership. Announced MAY06 the SBC hydraulic unit (pump) was extended from the original 4 years/50,000 miles to 10 years with no mileage limitation.

brabus2ner

thanks for the info, i will tell my adviser to check my breaks out.