Would appreciate commnets on wheter it's advisable to avoid used 2004/5/6 E Class's due to the electronic brake assist. Apparently MB has abandoned this setup due to numerous customer complaints. Was wondering if this is just overhyped or worth avoiding. My friend has a pristine 2004 E Class, 4k miles, may be selling it. Is it worth considering or not?

Thanks...

__________________
...Bob

1994 E320
2001 Corvette Coupe
1998 Jetta
1996 Camry

There are two systems, EBS and SBS.

EBS is emergency brake assist, and I wouldn't worry about that as much. It applies more brake force than you do, if you hit the pedal fast.

SBS is another story. In normal operation (not fail-safe), it applies the brakes for you. There's a sensor that determines the pedal movement, and the computer runs the brakes. The computer also closes the valves between the master cylinder and the brakes, so the master cylinder itself provides no fluid pressure. In fail-safe mode, these valves are open, and the master cylinder provides pressure to the front brakes only.

SBS looks to be a nice system, as long as the eletronics work properly. It provides pressure to the individual calipers as needed, using the wheel speed sensors. But MB is not known for the reliability of its electronic systems, so I'd steer clear of SBS brakes. Also, with SBS, you must deactivate the system to work on the brakes. This takes the Star diagnositic tool or a special tool just for that job, which costs about US $200.

I've never heard of EBS. Do you mean BAS (brake assist system)? This is a feature on MB vehicles with traditional braking systems. It uses a brake booster which can supply full brake force under certain conditions. This has been around for several years. Depending on the year and model it's either incorporated into the traction control system or operates as a stand alone system.

Senso-Tronic Brake Control, or SBC is the "brake-by-wire" system found on 2003-06 E-Class MB's, as well as CLS's. I've seen this system trashed on this Forum (and others), but in reality it's quite reliable and offers good performance. True, it's been the subject of several recalls, but I've only seen two system failures since the system was introduced and these were on very early 211's. The overwhelming majority of customer complaints concern the sound of the charging pump. Many new owners were unfamiliar with this, and brought their cars back thinking something was wrong. MB came up with a fix to reduce the noise heard from inside the car and everyone (almost) was happy.

I'm not saying that SBC is/was the greatest idea MB ever had though. From a business standpoint it's been a disaster, and I often wonder why they would abandon a perfectly adequate system. In real-world driving, SBC offers only marginal gains in performance, IMHO. This, along with the increased cost and complexity, is why it's been a failure. At least MB has stepped up though. They've extended the warranty for the SBC system to 100,000 miles, and I think, ten years.

Works for airplanes, and fighter jets.

Not saying brake by wire is a good idea for a car, but fly by wire has been in use for a long time.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Thanks. That is what I mean. Sorry for the confusion.

Thanks very much for the explanations. The braking system I was referring to(not certain whats it called) is where brakes are applied in anticipation, based on driver pedal pressure and rapidity of pedal movement. My recollection of driver complaints was too jerky when trying to feather the brakes in stop&go traffic. Some claimed overly sensitive. However, that being said, I'm concerned about down the road troubles with this setup as car ages, seeing as I keep a "good" car at least ten+ years. I'm was shying away from buying my friends 04 Eclass. Mentioned this to my MB salesman friend and he said I shouldn't pass it up based on this concern, said its not an issue. Some of your comments seem to share this concern, however I was unaware of the extended warranty gesture from MB.

Thanks again...

__________________
...Bob

1994 E320
2001 Corvette Coupe
1998 Jetta
1996 Camry

BAS is the system that started in 1998 that allows the brake system to go to full ABS quickly. Sensors on the brake booster send signals how quickly you hit the brake pedal.

SBC is the hydraulic system starting in 2002 (USA) that has very high pressure to apply the brake system...discontiued on all models except the R230 chassis & the SLR.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator