[ratapeludismo]

Originally Posted by avocet

Has the disc warpage been confirmed with runout checks? Is your pad wear within each caliper even?

Although feuer's diagnosis seems likely, there are many details that are missed over Internet diagnosis'.

Perhaps there is an underlying bushing/suspension condition that only manifests itself when there is a slight imbalance or uneven braking force(from pad deposits/disc wear)?

Do you left foot brake? Have all 4 discs been replaced every time?

And what discs were used? Inferior discs can and will cause premature warpage issues.

On two occasions the runout checks showed that everything was ok. No deformation !! but there was vibration in the steering wheel only when braking.
Clean discs sandblasted did not work.
I've only changed the disks least the first time. The tablets are the same.
silent blocks changed
suspension changed
I'm desperate.

[feuer]

Originally Posted by ratapeludismo

On two occasions the runout checks showed that everything was ok. No deformation !! but there was vibration in the steering wheel only when braking.
Clean discs sandblasted did not work.
I've only changed the disks least the first time. The tablets are the same.
silent blocks changed
suspension changed
I'm desperate.

When you brake hard, for long time, and when brakes are hot, and is vibrating, does it continue to vibrate for a little bit after you take you foot off the brake pedal?

[David0ff]

I recently had a slight vibration under braking which I found out was from an unbalanced wheel. The wheel had been barebacked a week prior, one of the stickys flew off. The vibration was exactly the same as when you have finished rotors which I knew was not the case since at the time the rotors/pads had 10K kms of usage.

Road force balance your wheels 1st before swaping anything. You may have a slighly ovalize or flatish tire.
Check the integrity of your front lower arm bushing, the big round soft juicy one.
Check all ball joints and tie rods in/out.
It is not possible that the disks warp like you describe, even track usage wont do what you are experiencing.

[feuer]

Originally Posted by David0ff

I recently had a slight vibration under braking which I found out was from an unbalanced wheel. The wheel had been barebacked a week prior, one of the stickys flew off. The vibration was exactly the same as when you have finished rotors which I knew was not the case since at the time the rotors/pads had 10K kms of usage.

Road force balance your wheels 1st before swaping anything. You may have a slighly ovalize or flatish tire.
Check the integrity of your front lower arm bushing, the big round soft juicy one.
Check all ball joints and tie rods in/out.
It is not possible that the disks warp like you describe, even track usage wont do what you are experiencing.

OK, and how do you explain the vibration disappearing after disks replacement?

[ratapeludismo]

[Meeni]

Originally Posted by feuer

OK, and how do you explain the vibration disappearing after disks replacement?

An oval wheel, or even improperly balanced will make the pad deposit unevenly on the disk, making it feel like it is warped.

Checking that your wheels are true and balanced is a good start. A bent wheel can cause this. You can also check that your shocks and springs have not had a catastrophic failure, but since you have done lots of work I'd expect any shop worth it salt would have found it already.

[ratapeludismo]

Originally Posted by Meeni

An oval wheel, or even improperly balanced will make the pad deposit unevenly on the disk, making it feel like it is warped.

Checking that your wheels are true and balanced is a good start. A bent wheel can cause this. You can also check that your shocks and springs have not had a catastrophic failure, but since you have done lots of work I'd expect any shop worth it salt would have found it already.

You think your sanding discs and a balanced dynamic would be solved?
What is strange is that when I drive does not vibrate. Only vibrates when braking.

If improperly balanced wheels always vibrate?

Thanks for the help

[ratapeludismo]

Originally Posted by feuer

OK, and how do you explain the vibration disappearing after disks replacement?

At three semans become vibrations.
It is that everything is very strange !!
In those three weeks I'm still in the period of adaptation pad-disc.
No hard braking and very carefully

[feuer]

Originally Posted by ratapeludismo

You think your sanding discs and a balanced dynamic would be solved?
What is strange is that when I drive does not vibrate. Only vibrates when braking.

If improperly balanced wheels always vibrate?

Thanks for the help

Correct, if wheels are off balance car will vibrate at speed, and will vibrate all the time regardless whether you are braking or not. Is jut not very plausible scenario. I personally have been driving my car with imperfectly balanced front wheels for years now, they are slightly bent, and experiencing zero vibrations when I brake.
Like I already asked you: let us know if vibrations continue even after you get you foot of the brake pedal. When brakes are hot. That is good sign that you have caliper or caliper piston sticking.

[avocet]

A slight imbalance or out of round wheel thst does not cause vibes under non braking situations might cause a vibe when combined with other factors like minuscule rotor warpage, uneven pad deposits on rotors and worn suspension components... braking with worn bushings and bearings can cause your front wheels to go toe out which is an unstable condition. Combined with brake issues you can end up with shimmy... shimmy fast enough and you get a vibration!

[Meeni]

Originally Posted by feuer

Correct, if wheels are off balance car will vibrate at speed, and will vibrate all the time regardless whether you are braking or not.

Your own point is very reasonable, and I advise the op to follow up on sticking caliper pins. But you are missing the mark regarding the effect of suspension problems on brake deposits.

If you have a wheel that is out of true, oval, or suspension issues that make the wheel basically "dribble" under braking, this is going to put brake deposit on the disks in a crest and valleys fashion. What makes the car vibrate is not directly the wheel imbalance or the underlying problem, but the uneven pad deposit resulting from it, which will manifest only under braking.

I have had the issue myself, changing (or sanding) the disks would fix the issues for a couple hundred miles, but it would invariably come back. After my bent wheel got corrected, the issue never recurred.

[ratapeludismo]

Originally Posted by feuer

Correct, if wheels are off balance car will vibrate at speed, and will vibrate all the time regardless whether you are braking or not. Is jut not very plausible scenario. I personally have been driving my car with imperfectly balanced front wheels for years now, they are slightly bent, and experiencing zero vibrations when I brake.
Like I already asked you: let us know if vibrations continue even after you get you foot of the brake pedal. When brakes are hot. That is good sign that you have caliper or caliper piston sticking.

Hello!!
Vibration occurs when braking at high and low speeds and also cold and hot discs.
A foot off the brake pedal vibrations disappear in all cases.
Thanks for the help!

[mojobmw_e90]

Originally Posted by ratapeludismo

Hello!!
Vibration occurs when braking at high and low speeds and also cold and hot discs.
A foot off the brake pedal vibrations disappear in all cases.
Thanks for the help!

I would have to say feur is right.

I know for a fact 3 out of my 4 wheels have minor bends and will get replaced over winter. When they balanced them they told me this and I can see the tire and wheel having a slight bump when spinning. They added weights to help fix it.. Now this did not affect any steering shake or anything when braking at any speeds. Sure have very little vibrations at 100+ but braking it's perfectly fine

[ratapeludismo]

Originally Posted by Meeni

Your own point is very reasonable, and I advise the op to follow up on sticking caliper pins. But you are missing the mark regarding the effect of suspension problems on brake deposits.

If you have a wheel that is out of true, oval, or suspension issues that make the wheel basically "dribble" under braking, this is going to put brake deposit on the disks in a crest and valleys fashion. What makes the car vibrate is not directly the wheel imbalance or the underlying problem, but the uneven pad deposit resulting from it, which will manifest only under braking.

I have had the issue myself, changing (or sanding) the disks would fix the issues for a couple hundred miles, but it would invariably come back. After my bent wheel got corrected, the issue never recurred.

But the disks are attached to the hub. (Bushings also changed)
Though the wheels are unbalanced or oval does not affect the hub or alos discs.
I'm wrong?
Thanks for the help guys.
Among all solve this!

[feuer]

Originally Posted by ratapeludismo

Hello!!
Vibration occurs when braking at high and low speeds and also cold and hot discs.
A foot off the brake pedal vibrations disappear in all cases.
Thanks for the help!

Get the brakes hot, really hot, more you brake more they will vibrate, see if it progresses, and then see if vibrations continue for few seconds after you get your foot of the brake.

[ratapeludismo]

Originally Posted by feuer

Get the brakes hot, really hot, more you brake more they will vibrate, see if it progresses, and then see if vibrations continue for few seconds after you get your foot of the brake.

I will test tomorrow.
Thank you very much!

[ratapeludismo]

Originally Posted by feuer

Get the brakes hot, really hot, more you brake more they will vibrate, see if it progresses, and then see if vibrations continue for few seconds after you get your foot of the brake.

I did the tests.
When you lift off the accelerator NO vibrates the steering wheel.
But what I have noticed that with very hot disks vibrates more.
What can be the cause?

[ratapeludismo]

I keep thinking that can cause the air guide
air guide M 335i --------------Left 51748045363 . Right 51748045364
air guide M other engines -----Left 51748045361 . Right 51748045362 (wear this)

[ratapeludismo]

Not having enough ventilation air is heated disk and deposits are adhered pads causing vibrations?
Thank you

[feuer]

Originally Posted by ratapeludismo

I did the tests.
When you lift off the accelerator NO vibrates the steering wheel.
But what I have noticed that with very hot disks vibrates more.
What can be the cause?

Try the caliper rebuild kit and better brake fluid with greater boiling point. I assume from the heat the caliper pistons are expending and not fully retracting thus vibration more when the brakes are cold. The cooling from your existing ducts is sufficient so do not worry about that.

[ratapeludismo]

Originally Posted by feuer

Try the caliper rebuild kit and better brake fluid with greater boiling point. I assume from the heat the caliper pistons are expending and not fully retracting thus vibration more when the brakes are cold. The cooling from your existing ducts is sufficient so do not worry about that.

But when I change disks by new works perfectly.
But the vibrations back soon (about a month).
I can retrieve new disks or I have to throw them away?
Thanks for the help.

[techwhiz]

Originally Posted by ratapeludismo

But when I change disks by new works perfectly.
But the vibrations back soon (about a month).
I can retrieve new disks or I have to throw them away?
Thanks for the help.

Your pads are leaving deposits.
http://stoptech.com/technical-suppor...nd-other-myths

Stoptech, brake components manufacturer, indicates that disc warpage is a rare event. Read the article. Buy better pads.