There's a new bulletin that just came out for those of you that hear a buzzing noise from your brake system. A pulsation damper is to be retrofitted into the suction line near the main SBC hydraulic unit.

 

thanks a lot mbtech, i hear this noise, so now it isnt usuall? thanks, ill talk to my dealer

 

mbtech,

any chance you've got an SB number associated with this bulletin?

 

Of course!: P-B-42.46/27a

 

I just picked up my wife's '04 E320 Wagon about a week ago and have logged 500 miles on the car. It makes a whine/buzzing noise (very high pitched) everytime I apply the brake pedal.

It's VERY annoying driving at night with the radio off since it's dead quiet in the car. I can't stand it and Laguna Nigel techs said the sensotronic brakes make a lot of noise and people complain all the time and to join the crowd!!

I didn't even test drive the car since we just traded in the '01 E320 Wagon assuming the new one was a great car. The brakes are completely annoying.

Sould I try another dealer service center?

 

I have an E320 with a build date of 3/2004 and I have no noise at all other then the faint sound of the pump running occasionally.

What I do have is a thump from the brakes when I apply and release them when driving very slowly.

I don't suppose the pulsation damper would cure the problem.

 

This is for sound #1

" I just picked up my wife's '04 E320 Wagon about a week ago and have logged 500 miles on the car. It makes a whine/buzzing noise (very high pitched) everytime I apply the brake pedal."

The other posts are talking about sound #2

There is some important cross talking here!

#1 The noise we are talking about here is the high pith electrical vibration noise that occurs when the brake pedal is pushed. For that, I don’t know of any fix yet.

#2 The Pulsation Damper is for another noise. When the SBC is used a lot and every time that the booster has to accumulate pressure, the SBC pump turns on. It sounds like a pump working. It will make this noise most every time you start the car after a while of sitting. This sound is annoying.

One sound has nothing to do with the other. Sound #1 is very faint and happens most every time your foot is on the brakes and the car is quiet. Sound #2 is a much louder and obvious sound and only happens on occasion.

I went to my dealer complaining about sound #1 and they interpreted is as being sound #2. They installed the pulsation damper and sound #2 is almost gone all together. Sound #1 is still there.

Also, the pulsation damper fix, that also requires a hydraulic line change it a bit much. Some dealers have found that just installing the pulsation damper is enough. There have been cases where all the air in the brake lines was not purged and people lost brakes after driving away from the dealer. I just had the Pulsation damper changed and opted to keep the brake lines. I compared the sound with a loaner car that they did the whole repair to and sound #1 was still there. Sound #2 was the same intensity. There was no difference between my car, which did not have the hydraulic line change and the loaner E that did when it came to noise #2.

So, I strongly recommend that pulsation damper repair. It makes the car much quieter. Changing the hydraulic line is up to you.

The repair for sound #1 is a mystery to me. I hope this clarifies the SBC brake noise we keep on talking about. They are two very distinct noises. Also, remember that it is a “damper” some people say it’s a “dampener.” A “dampener” would be something to make things wet. Much like a “yaw damper” on an airplane, a damper decreases oscillations of some sort or another.

I hope this fixes the crosstalking,

Steve Aguirre

 

Thanks for the info there bro, but this is hardly "new" news...... I've had this bulletin number for months as Konigster was so kind to provide it

Thanks again.

 

I also heard the very faint high pitch noise, when I first picked up the E last year. The noise has disappeared by itself after a few weeks.

 

I was told today that this tsb only applies to certain vin ranges. Does anyone have additional info on this fix? thanks.

 

I have my car serviced there too. Talk to Nader Sadhigi. He is awesome and will take good care of you. Give him the bulletin for this and they will take a look at it. Laguna Niguel is a great place.

 

There are two bulletins concerning SBC noise:

P-B-42.46-27c DEC03
Buzzing Noise during Pressure Buildup from SBC system

P-42.46-32A JAN04
Whistling Noise When Depressing Brake Pedal

 

Do you have access to the details for these 2 tsbs(year/vin)? I want to see if my car is included....thanks.

 

The TSB that directs the tech to install the pulsation damper, if a buzzing noise is reported by the coustmer, does not include any language that I, the shop forman or SA could find, that directs them to also change the lines out.

Those that have had this done....can you tell if it has reduced the frequency that the pump comes on in the first place? My shop forman told me that the pump will still come on as frequently as it is now...which is about every other or 3rd brake application.

 

I'm sure that 'Wobbles' has complained quite strongly about noise #1

Does anyone know how he got on? Was it resolved?

Wobbles are you out there?

Good morning everyone,
John

A sunny but cool morning in Torquay

 

Hi everyone,

Yes, I screamed my head off with regards to the high pitched noise ... and, after 2 attempts, the dealer managed to deaden the noise (greatly reduced, but not gone completely) ... I have NO idea how/what they did, but my head doesn't spin that much whenever I depress the brake now

 

Morning Wobbles,
Nice to hear from you again, and I am so very disappointed to hear that your car is still not quite right.

I have read somewhere that E-class for the Far Eastern market are being produced out there. Is this correct? or is it more 'journalistic licence'?

Take care, and do not settle for less than what YOU want!
John

 

Hi glojo

I think there will be E-classes produced in China, in the future, but not as yet. My E-class was built in Germany ... but I really don't know if that's a good thing or not, with the minor irritations that have surfaced thus far (OK, so I'm being fussy).

 

Morning Wobbles,
Thanks for clarifying that. You are definitely not being fussy; I would suggest just the opposite. You have been both extremely tolerant and unlucky with the problems you have had to deal with. Quality control seems to be less of a priority in this modern era, vehicles are leaving Germany with horrible minor problems that should have been detected. If not detected at the factory then the PDI needs to be more vigorous.

If defects can be instantly noticed by the new owner, then surely they should never have got passed a professional inspector who is paid to find just these minor faults. Loose seats, rattles and other strange noises, electronic equipment not working, minor scratches etc. etc.


Bye for now,

John
A very sunny cool morning in Torquay

 

Just had mine done. NO pump noise heard at this time.

According to the invoice P.B. 42.46/27D was compleated.

(Install SBC Pulsation Dampner Suction Hose as per DTB P.B 42.46/27D)