[fantanas]

Hello everyone,

I am having a bit of an issue with my BMW and I would need some support from the forum.

I have a 2015 435d X-Drive F33 M-Sport. I recently changed my rotors and parts (fronts) because I was experiencing vibrations under braking. After 200-300 miles, out of the blue the car started doing it again with the new components.

Some interesting points that I found:

1. This happens after I have been driving for a while at motorway speeds. Suddenly braking results in vibration. I could have been driving for 20 minutes without anything
2. This happens the first time when braking from speeds above 80mph. Then it happens at lower speeds as well.
3. I don't get vibration if I brake while turning.
4. I feel the vibrations on the steering and brake pedal.
5. The braking issue is audible as well.
6. I don't feel that braking performance is compromised.
7. This happens at any drive mode, any gear and any road surface.
8. When the car is not driven for a while (a few hours) this stops and #1 needs to happen.
9. I don't see any suspension or brake related faults through OBD.
10. When braking the whole car shakes quite bad. The vibration is quite violent.
11. I don't experience any vibration of that level during normal driving (not braking).

This is quite puzzling. I took it to a garage and he has no ideas as well. We were thinking that it could be ABS sensors or something, but I get no related faults and I would imagine it would be happening all the time. The rotors are brand new and I haven't hit any potholes, or standing water. The first time it happened after the rotor/pad change it wasn't hard braking. Could it be pistons from the callipers sticking?

Any ideas are more than welcome. I haven't been driving the car for a while and now that I have a chance to enjoy it this happens.

[redbullfan]

Have you tried inspecting your thrust arm bushings?

[Billfitz]

Sticking pads dragging on one or more rotors could cause rotor heat build over time, which can cause warp (it's not actually warp, but that's the name applied to uneven rotors). That can cause pulsating brakes. I'd make sure the pads are correctly lubricated so they can't stick.

[Watsey]

Originally Posted by Billfitz

Sticking pads dragging on one or more rotors could cause rotor heat build over time, which can cause warp (it's not actually warp, but that's the name applied to uneven rotors). That can cause pulsating brakes. I'd make sure the pads are correctly lubricated so they can't stick.

Exactly my thoughts also. I had this happen on my car yesterday (Stoptech Trophy BBK), and I strongly suspect a sticking pad or a seized piston in the caliper.

Constant friction between pad/disc causing the front offside disc to overheat, leading to rumbling, binding, and severe shuddering as soon as I touched the brake pedal.

The only solution was to get off the motorway, drive very slowly until it had cooled (note to the OP - don't stop the car, it'll likely lead to significant pad transfer to the disc which makes the shuddering problem even worse), and then had to drive at <60mph for the remaining 50 miles of my journey home.

The front brakes will need to be stripped, inspected, and all the contact points plus the rear of the pad backing plates re-coated in ceramic grease.

I just hope it hasn't scorched / warped the disc - Stoptech 380mm discs are £1,000 for a pair and have only been on the car for ~2K miles.

[zatelli]

If neither brake pads nor rotors are causing the issue you described, I'd have the garage inspect the clutch / flywheel.

[cfm56d7b]

Originally Posted by Watsey

Exactly my thoughts also. I had this happen on my car yesterday (Stoptech Trophy BBK), and I strongly suspect a sticking pad or a seized piston in the caliper.

Constant friction between pad/disc causing the front offside disc to overheat, leading to rumbling, binding, and severe shuddering as soon as I touched the brake pedal.

The only solution was to get off the motorway, drive very slowly until it had cooled (note to the OP - don't stop the car, it'll likely lead to significant pad transfer to the disc which makes the shuddering problem even worse), and then had to drive at <60mph for the remaining 50 miles of my journey home.

The front brakes will need to be stripped, inspected, and all the contact points plus the rear of the pad backing plates re-coated in ceramic grease.

I just hope it hasn't scorched / warped the disc - Stoptech 380mm discs are £1,000 for a pair and have only been on the car for ~2K miles.

Great advice.

As a side note, under normal driving conditions (including spirited driving) well engineering rotors should consistently dissipate heat without any issues.

It's not normal for almost $1,500 USD pair of rotors to retain so much heat that the braking compound - as it's being shaved by the frictional forces - binds to the rotor surface. Even OEM Zimmermann smooth front rotors (370x30mm M Sport) rarely exhibit this issue.

What brake pads does you car have?

[anielsen71]

Hi there
I recently had similar experience with my F36 435d.
Turned out to be bushings in one of the suspension arms. Don't know the English word of it.
Get them checked. Was not much play in the bushing but enough to make it wobble a little bit under braking.

[Shred Sled]

https://www.wagnerbrake.com/technica...ke-judder.html

[Watsey]

Originally Posted by cfm56d7b

Great advice.

As a side note, under normal driving conditions (including spirited driving) well engineering rotors should consistently dissipate heat without any issues.

It's not normal for almost $1,500 USD pair of rotors to retain so much heat that the braking compound - as it's being shaved by the frictional forces - binds to the rotor surface. Even OEM Zimmermann smooth front rotors (370x30mm M Sport) rarely exhibit this issue.

What brake pads does you car have?

An update, and an answer.

It was exactly as I suspected - one of the three inner pistons in the right hand caliper had stuck. This was surprising as all the pistons have dust boots, and none of them are damaged. The piston could extend under the hydraulic pressure injury the braking system, but it wouldn't retract. This was causing part of the brake pad to remain in constant contact/pressure with the disc causing heat build-up.

Placing a suitable diameter screwdriver between the outer face of the disc and the caliper (to brace the disc and therefore avoid any risk of bending the disc bell housing) I used another large screwdriver to apply leverage on the stuck piston. It eventually broke free and slid smoothly all the way to its most retracted position in its caliper housing.

Obviously I checked all the others, in both calipers. All fine. Using a digital gauge, and with the disc bell housings bolted to the hubs, run-out was measured as no more than 0.15mm which from experience is usually not enough to cause shudder on its own.The run-out is unlikely to be due to any unevenness on the face of the hubs as they are pretty much new - the front bearings and hubs were replaced less than 2,000 miles ago partly as preventative maintenance and partly because some wear had been noticed (not enough to cause bearing whine, but enough to indicate that they were past their best).

This was a goods time to clear all the abutment plates of baked-on brake dust, as well as cleaning the pad backing plates and re-applying ceramic grease.

The car is running Pagid RSL1 all round and it was obvious from the incessant squealing that the contact surfaces needed cleaning and re-greasing. They'll never be completely quiet (because of the high metal content in this pad compound), but they are much less intrusive now and pedal feel is super-smooth and easily modulated once again.

More importantly, no more rumbling and overheating.

[cfm56d7b]

Originally Posted by Watsey

An update, and an answer.

It was exactly as I suspected - one of the three inner pistons in the right hand caliper had stuck. This was surprising as all the pistons have dust boots, and none of them are damaged. The piston could extend under the hydraulic pressure injury the braking system, but it wouldn't retract. This was causing part of the brake pad to remain in constant contact/pressure with the disc causing heat build-up.

Placing a suitable diameter screwdriver between the outer face of the disc and the caliper (to brace the disc and therefore avoid any risk of bending the disc bell housing) I used another large screwdriver to apply leverage on the stuck piston. It eventually broke free and slid smoothly all the way to its most retracted position in its caliper housing.

Obviously I checked all the others, in both calipers. All fine. Using a digital gauge, and with the disc bell housings bolted to the hubs, run-out was measured as no more than 0.15mm which from experience is usually not enough to cause shudder on its own.The run-out is unlikely to be due to any unevenness on the face of the hubs as they are pretty much new - the front bearings and hubs were replaced less than 2,000 miles ago partly as preventative maintenance and partly because some wear had been noticed (not enough to cause bearing whine, but enough to indicate that they were past their best).

This was a goods time to clear all the abutment plates of baked-on brake dust, as well as cleaning the pad backing plates and re-applying ceramic grease.

The car is running Pagid RSL1 all round and it was obvious from the incessant squealing that the contact surfaces needed cleaning and re-greasing. They'll never be completely quiet (because of the high metal content in this pad compound), but they are much less intrusive now and pedal feel is super-smooth and easily modulated once again.

More importantly, no more rumbling and overheating.

Knowing the root cause and identifying correct solution is one of the most satisfying feelings. Glad the problem was resolved.

[fantanas]

I am glad to hear that your problem is solved.

I have been quiet for a while because of work life, but my problem is still there.

My symptoms are:

1. This happens after I have been driving for a while at motorway speeds. Suddenly braking results in vibration. I could have been driving for 20 minutes without anything
2. This happens the first time when braking from speeds above 80mph. Then it happens at lower speeds as well.
3. I don't get vibration as bad if I brake while turning.
4. I feel the vibrations on the steering but not on the pedal.
5. The braking issue is audible as well.
6. I don't feel that braking performance is compromised.
7. This happens at any drive mode, any gear and any road surface.
8. When the car is not driven for a while (a few hours) this stops and #1 needs to happen.
9. I don't see any suspension or brake related faults through OBD.
10. When braking the whole car shakes quite bad. The vibration is quite violent.
11. I don't experience any vibration of that level during normal driving (not braking).

A quick update on some investigation that was done during my little free time.

My rotors are straight no warping. Brake pads look fine and all pistons appear to move freely (when cold). I checked the wheels and some were a bit bent, which was fixed but no improvement. The guide pins were cleaned and the brake pads sanded a bit (in case they had overheated at some point)

The brake pads and rotors are 400miles old.

The garage today said that the one hub looks a bit bent. Would it be possible for that to be causing my issue?

Please help me I am going crazy.

Originally Posted by Watsey

An update, and an answer.

It was exactly as I suspected - one of the three inner pistons in the right hand caliper had stuck. This was surprising as all the pistons have dust boots, and none of them are damaged. The piston could extend under the hydraulic pressure injury the braking system, but it wouldn't retract. This was causing part of the brake pad to remain in constant contact/pressure with the disc causing heat build-up.

Placing a suitable diameter screwdriver between the outer face of the disc and the caliper (to brace the disc and therefore avoid any risk of bending the disc bell housing) I used another large screwdriver to apply leverage on the stuck piston. It eventually broke free and slid smoothly all the way to its most retracted position in its caliper housing.

Obviously I checked all the others, in both calipers. All fine. Using a digital gauge, and with the disc bell housings bolted to the hubs, run-out was measured as no more than 0.15mm which from experience is usually not enough to cause shudder on its own.The run-out is unlikely to be due to any unevenness on the face of the hubs as they are pretty much new - the front bearings and hubs were replaced less than 2,000 miles ago partly as preventative maintenance and partly because some wear had been noticed (not enough to cause bearing whine, but enough to indicate that they were past their best).

This was a goods time to clear all the abutment plates of baked-on brake dust, as well as cleaning the pad backing plates and re-applying ceramic grease.

The car is running Pagid RSL1 all round and it was obvious from the incessant squealing that the contact surfaces needed cleaning and re-greasing. They'll never be completely quiet (because of the high metal content in this pad compound), but they are much less intrusive now and pedal feel is super-smooth and easily modulated once again.

More importantly, no more rumbling and overheating.

[fantanas]

Bump!

I am desperate

[fantanas]

Bump

[fantanas]

A quick update, I changed the wheel hub but the problem is still there unfortunately. I am running out of ideas please help!

[cfm56d7b]

fantanas, these problems can be frustrating. The good news - anything repeatable will eventually reveal the root cause. Few questions:

- Are you the original owner?
- What was the mileage when these vibration symptoms started?
- What rotors and pads were recently installed? Brand, etc.
- Were the calipers inspected for any sticking pistons?
- Master cylinder pressure: within expected range?
- Brake lines OK?
- Suspension: check arm bushings?
- Front wheel bearings OK?

Vibration means that some rotational components are oscillating for some reason.

The question is what components ...

[fantanas]

cfm56d7b thank you for the reply. I appreciate the help.

Answers to your questions:

- Are you the original owner? - No, Bought it 3 years and 35k miles ago.

- What was the mileage when these vibration symptoms started? - 77k miles, it has been happening for the past 500 miles

- What rotors and pads were recently installed? Brand, etc. - Zimmerman rotors and pagid (I think) pads.

- Were the calipers inspected for any sticking pistons? - visual inspection showed nothing. When pushing them in they go in easily.

- Master cylinder pressure: within expected range? - haven't checked. Can I do that with ISTA?

- Brake lines OK? - No swelling they look ok. No leaks.

- Suspension: check arm bushings? The garage inspected suspension components multiple times and there is no play anywhere.

- Front wheel bearings OK? - They are ok no noises or anything. The left one was replaced with the wheel hub today.


Any ideas?

Originally Posted by cfm56d7b

fantanas, these problems can be frustrating. The good news - anything repeatable will eventually reveal the root cause. Few questions:

- Are you the original owner?
- What was the mileage when these vibration symptoms started?
- What rotors and pads were recently installed? Brand, etc.
- Were the calipers inspected for any sticking pistons?
- Master cylinder pressure: within expected range?
- Brake lines OK?
- Suspension: check arm bushings?
- Front wheel bearings OK?

Vibration means that some rotational components are oscillating for some reason.

The question is what components ...

[redbullfan]

Originally Posted by fantanas

cfm56d7b thank you for the reply. I appreciate the help.

Answers to your questions:

- Are you the original owner? - No, Bought it 3 years and 35k miles ago.

- What was the mileage when these vibration symptoms started? - 77k miles, it has been happening for the past 500 miles

- What rotors and pads were recently installed? Brand, etc. - Zimmerman rotors and pagid (I think) pads.

- Were the calipers inspected for any sticking pistons? - visual inspection showed nothing. When pushing them in they go in easily.

- Master cylinder pressure: within expected range? - haven't checked. Can I do that with ISTA?

- Brake lines OK? - No swelling they look ok. No leaks.

- Suspension: check arm bushings? The garage inspected suspension components multiple times and there is no play anywhere.

- Front wheel bearings OK? - They are ok no noises or anything. The left one was replaced with the wheel hub today.


Any ideas?

Like I have mentioned to you before in the beginning of the thread, have you checked your thrust arm bushings aka Control Arms?

[fantanas]

Originally Posted by redbullfan

Like I have mentioned to you before in the beginning of the thread, have you checked your thrust arm bushings aka Control Arms?

The garage said that they inspected them. Which ones are those?

Can I do any testing my self?

The noise/vibration is quite periodic. Wouldn't it be due to a rotating part?

[cfm56d7b]

"3. I don't get vibration if I brake while turning."

fantanas, remote diagnostics are always a difficult proposition. If the above is correct, control arms require a closer inspection. They are called control arms because they control the wheel and suspension through the entire range of motion. Control arms have inner and outer ball joints - which rotate and spin as the control arm goes through its movements. The ball joints do wear as miles accumulate.

If vibration disappears when the suspension geometry changes, the focus should be centered on components which manage / participate in suspension geometry changes.

I sense you might need to find a more experienced shop.

Additional questions:

- What Pagid pads were installed? OEM equivalent or some other type? Question about brakes pads generates many opinions. Softer OEM pads have one advantage. They preserve rotor life (and rotor geometry) and have an aggressive initial bite - very suitable for daily driving.

- What rotors: Zimmermann single piece or 2-piece? I doubt the rotors are the culprit but it's prudent to have complete information.

[fantanas]

Originally Posted by cfm56d7b

"3. I don't get vibration if I brake while turning."

fantanas, remote diagnostics are always a difficult proposition. If the above is correct, control arms require a closer inspection. They are called control arms because they control the wheel and suspension through the entire range of motion. Control arms have inner and outer ball joints - which rotate and spin as the control arm goes through its movements. The ball joints do wear as miles accumulate.

If vibration disappears when the suspension geometry changes, the focus should be centered on components which manage / participate in suspension geometry changes.

I sense you might need to find a more experienced shop.

Additional questions:

- What Pagid pads were installed? OEM equivalent or some other type? Question about brakes pads generates many opinions. Softer OEM pads have one advantage. They preserve rotor life (and rotor geometry) and have an aggressive initial bite - very suitable for daily driving.

- What rotors: Zimmermann single piece or 2-piece? I doubt the rotors are the culprit but it's prudent to have complete information.

The Pads are OEM equivalent.

Rotors probably are one piece.


How can I test the bushings?

Any other tests I need to do?

[Watsey]

Originally Posted by zatelli

If neither brake pads nor rotors are causing the issue you described, I'd have the garage inspect the clutch / flywheel.

The 435d is only available as an auto.

[Watsey]

fantanas have you tried bedding your brakes ?


If pad deposits have formed on the discs the friction coefficient will increase as the heat increases, which can cause shudder. Bedding the brakes may help to provide a more consistent friction layer.

The other option is to replace the pads with a more aggressive compound - this is one way to clean the faces of the discs. Ferrodo DS2500 are reasonably priced and would probably do the job.