Wobble when brake applied

[kenny1000]

Hello to all the clever people out there, I currently have 2 new problems and seeking some more advice. When I press the brake pedal while traveling at speed I can feel a wobble on the car but nothing on the steering wheel. Could this be one of the back pads stuck.
Secondly the drivers window no longer goes up automatically when the switch is flicked up, and when driven up by keeping the switch up, at full travel it keeps trying to drive the window up and does not cut out. Souds awful and cannot be good for it. Any ideas will be gratefully appreciated

 

[ucr]

New brake discs needed

 

[kenny1000]

Why new brake disc? Just want to know your reasoning? All 4 or just fronts or backs? Could it be a sticking caliper or pad. Its just the first time I have ever had this problem and an engineer by trade and like to work things thru. Just got home from work and will look at it tomorrow so looking for pointers

 

[donubenz]

Hi,
I was told by my garage that auto cars tend to have the drivers hold the brake pedal down at lights and junctions. This means that the pads are in contact with the disc and the different heat sink causes the discs to warp. I had two front ones replaced that had only done 10,000 miles on my W126 S class. I still drive this way but I guess the reason is feasible. It is definitely warped discs if you feel it in the foot pedal.
As for the window switch, Mercs use a thermal overload to stop the window so that if you get something stuck it will stop the glass rising. Others use proximity sensors which usually have a thermal break as well. I would disconnect the switch and seek a replacement thermal overload for the motor.
Don

 

[davidjpowell]

I understand that discs rarely warp nowadays, but the warm brake fiction pad can if hot enough leave a coating on the part of the disc that it has been in contact with.

 

[carat 3.6]

Warped front brake disc's are causing your shuddering. Change the front disc's and pads, and make sure the calipers are not sticking in any way.

 

[chrissoar1]

Had the same issue with my w211, have now got new discs and pads on order.

 

[BlackC55]

It may not be just the front discs, it could be the rear too.

Is the car a 203?

 

[BlackC55]

Check:

Front suspension for play
Discs runout and corrosion
Front hub corrosion (very very common on a 203 and 209)

 

[goodpw]

Hi All. Not a newbie but been away so long I've forgotten my user ID(fairly sure it was goodyUK)+Password+changed my email, easier to start from scratch.
I'm having a similar problems with my CLK500 Avantgarde 2003, 98K miles. I had quite a bit of brake judder through the pedal but could not feel it through the steering wheel & the car stopped straight with no pulling to either side.
I replaced the front discs with drilled items also changed the pads (cleaned calipers). the judder seemed to reduce but was still present.
I changed the rear pads (cleaned calipers) but not the rear discs. still juddering.
Tried several hard stops from increasing speeds to a stop, still juddering.....what now.
The handling does feel slightly worse than when I bought the car 3 years ago so what are the chances of worn bushes/joints ? if so what is most likely to be prime suspect ?
Cheers in advance.
Phil.

 

[kenny1000]

Thanks for all the suggestions and advice. Will have a look tomorrow and let you know what I find

 

[WDB124066]

Like Olly said, measure the disks for runout before replaceing them, otherwise you may be replacing something that is just fine......

 

[kenny1000]

Solved the problem. When I changed the back pads one of the calipers was siezed. I freed it odd and cleaned the disc front abd back, but missed a bit of rust at the back. When the brake was applied this bit of rust was hitting the new pad and slowly wearing in. Now that it has been properly cleaned, no more wobble at speed. Many thanks for all the help