Vibration in steering/Brake pedal

[GeorgeA]

At above 40mph a slight vibration is felt and can be seen in the steering wheel. At cruising speed the car is no longer running smoothly. When braking from 70mph vibration is felt thru brake pedal. Problem started after a flat tyre some time ago but has got progressively worse.

So new tyres have been fitted, a new set of MB alloys and numerous wheel balance/wheel swops undertaken with no improvement.

Have had the car checked by local tyre depot and MB main dealer but nothing obvious found. Bitterly disappointed with MB service in particular but might just go back.

Spoke to MB indie today who suggested brake disc or thrust torque bushes(whatever they are!!) could be the fault.

Any help with diagnosing this problem would be appreciated.

 

[Dieselman]

Sounds like brake judder caused by pad deposits on the disk or buckled wheel, but you've swapped wheels so shouldn't be that.

 

[AMGBoy]

sounds like brake judder to me
why not get the run out of the disc check

 

[television]

The front disc will have warped and gone out of true, quite a simple job to change them

 

[GeorgeA]

Brake judder sounds about right, is this resolved by fitting new discs and pads? How do I know if its the front or rear?

Thanks

 

[Dieselman]

Front is felt via steering, rear through seats.

 

[GeorgeA]

Felt thru steering so must be front. Been quoted £200 from indie to replace discs and pads, is this about right?

When I had a slow puncture on the front near side I drove the car for about 3 miles before this was pointed out to me, would this cause the front disc to warp?

Appreciate all the input - thanks

 

[television]

Felt thru steering so must be front. Been quoted £200 from indie to replace discs and pads, is this about right?

When I had a slow puncture on the front near side I drove the car for about 3 miles before this was pointed out to me, would this cause the front disc to warp?

Appreciate all the input - thanks

No this would not have caused it, it takes under 1 hour to change the parts

 

[GeorgeA]

No this would not have caused it, it takes under 1 hour to change the parts

Bit confused!. The tyre was completely flat by the time I stopped at a garage! Could this not have caused some damage?

Not sure if quoting 1 hour labour means £200 is a fair price or not.

 

[television]

Bit confused!. The tyre was completely flat by the time I stopped at a garage! Could this not have caused some damage?

Not sure if quoting 1 hour labour means £200 is a fair price or not.

Its not bad at that, whos disc will he be using and what pads, It take 1 hour to do both sides.

There is no way the a flat tyre can affect the disc, the disc are made of cast iron, not a very stable metal and can warp under a emergency stop or when frozen in the winter

 

[Dieselman]

Bit confused!. The tyre was completely flat by the time I stopped at a garage! Could this not have caused some damage?

Not to the disk only the tyre and wheel.

Before the garage change the disks have them check the run out and brake pad deposits. Even with no runout pad deposits can cause the symptoms you have.

We had an article on here where the tuning company/garage had never seen a warped disk, only ones with deposits.

I'm curious as my car had this fault under braking and after cleaning the disks with a sharpening stone it has been fine, well for the last 18 months anyway.

 

[GeorgeA]

Will take the car to the MB indie on Thursday and get the front discs checked. Will ask for MB parts to replace them.

Just had a quick look at the discs themselves, the front ones look immaculate and the rears are scored. Surprising for a car with only 27k on the clock !

Will post the outcome so as to bring this post to a conclusion - thanks again

 

[miro]

Spoke to MB indie today who suggested brake disc or thrust torque bushes(whatever they are!!) could be the fault.

Any help with diagnosing this problem would be appreciated.

I had a fault myself and I resolved it in the following way
- both front wheel bearings
- thrust arm bushes
- sway arm bushes (as also to AMG sway bar)
- steering arm tie rods

If the wheel bearing is cactus then the bushes will wear out sooner because of vibrations. Then as stated the discs and pads need looking at but then also bear in mind that the surfaces must be cleaned and aligned properly. This seems to escape the attention of some installers.

Dirt and rust can throw a disc off centre in the vertical plane and that will cause it warp much sooner in the life of the disc. The consumable parts are relatively low cost and all of the work mentioned in this post would only take 3 hours.

Installing new parts is always a good idea but the root of the problem in my car was the wheel bearing. That damage was caused by a pothole.

 

[GeorgeA]

Had a wheel bearing fault in one of my previous cars, many years ago, and was associated with horrendous noise. There are no such noises on this car. The wheels spin freely and there is normal play when the wheel is raised and rocked from top to bottom.

Interesting that you mentioned thrust arm bushes as the indie I spoke to said this was common on the W203.

I always come back to the fact that this all started after a puncture on the front left - is it possible that damage has occured to one or more of the components that you replaced?

All this input is of great help when I talk to the experts and try to resolve this issue once and for all.

 

[television]

This is a complicated subject. The disc are made of cast iron, it was not so many years ago that one method of stopping cast iron and mild steel going rusty was to heat up the metal and dip it in oil, it was called blacking and worked quiet well

We do know that disc rotors can become contaminated as well as warped, if the brake disc were very hot when you got your puncture, did some dirt or what ever get onto the rotors, and was absorbed into the metal.

Birdman did some very good articles on this subject.

 

[Vips]

sounds like the discs have warped.

 

[miro]

Had a wheel bearing fault in one of my previous cars, many years ago, and was associated with horrendous noise. There are no such noises on this car. The wheels spin freely and there is normal play when the wheel is raised and rocked from top to bottom.

Interesting that you mentioned thrust arm bushes as the indie I spoke to said this was common on the W203.

I always come back to the fact that this all started after a puncture on the front left - is it possible that damage has occured to one or more of the components that you replaced?

All this input is of great help when I talk to the experts and try to resolve this issue once and for all.

I never had a noise in the bearing. But I can assure you it put a lot of wear and tear on the left front side.

 

[miro]

This is a complicated subject. The disc are made of cast iron, it was not so many years ago that one method of stopping cast iron and mild steel going rusty was to heat up the metal and dip it in oil, it was called blacking and worked quiet well

We do know that disc rotors can become contaminated as well as warped, if the brake disc were very hot when you got your puncture, did some dirt or what ever get onto the rotors, and was absorbed into the metal.

Birdman did some very good articles on this subject.

One of the heads of ATE brake development recently held an information night and he explained that the life of braking systems is significantly reduced by poor installation methods - this includes warping of rotors which could easily be out of alignment with rust and dirt on the hub or other critical parts of the suspension assembly worn.

The brakes stop the car but they dont align parts which are not aligned correctly. Any misalignment in the seating position of the rotor or instability in operation of the suspension can reduce the life of the rotor.

At least rotors are relatively cheap.

 

[GeorgeA]

Thanks Miro - I will ask for the wheel bearings to be checked to be sure.

The rotor that has been mentioned several times, is this independant of the disc?

 

[television]

Thanks Miro - I will ask for the wheel bearings to be checked to be sure.

The rotor that has been mentioned several times, is this independant of the disc?

Rotor is the disc, its a USA term, I used the word as I had just done some USA post