M40i brakes - design flaw uncovered

[TheGingerOneNI]

Is this also an issue with the Supra? If not is there a different heat shield on them?

I have not heard that the Supra has the same problem. As far as I am aware it is only BMW and Mini that is affected, as the M Sport brakes in these models all use the same design of heat shield.

Then I wonder is the heat shield in the Supra different in design and can it be fitted to the Z4? If anyone has a friend with a Supra it might be worth looking in to.

 

[raven]

I was thinking of attaching it to the inside of the shield Jim, thus not making it any higher then the top of the shield, in fact a good few mm’s below the top.

Yes John, I can see that that might work but I would not want to void my warranty. BMW really should seriously consider designing a new front set of heat shields for the M Sport brakes, not only for the Z4 G29 but also for the several other series models where they are fitted. And they should retrospectively fit them to ALL affected models. I think the cost of recalling all the affected cars is what will prevent BMW from carrying this out. Shame on BMW as they are putting profits ahead of the extreme inconvenience that this is causing customers like me and several others that have been affected by this problem.

If you modified the disc shield i don’t think it would nullify the warranty for any other part of the car apart from the shield.
If the exhaust fell off for example, it would still be covered.
Rob

if the exhaust didn't get hit by the modified brake part flying off...

 

[raven]

Is this also an issue with the Supra? If not is there a different heat shield on them?

I have not heard that the Supra has the same problem. As far as I am aware it is only BMW and Mini that is affected, as the M Sport brakes in these models all use the same design of heat shield.

Then I wonder is the heat shield in the Supra different in design and can it be fitted to the Z4? If anyone has a friend with a Supra it might be worth looking in to.

The supra brakes look identical to me:




I doubt there are many parts actually designed by Toyota on the Supra

 

[ronk]

The backplates don’t look the same?
That’s where the problem starts I think.

 

[Argyll Andy]

Not conclusive as in the pictures they look different and the Supra lip looks to curve over the top of the discs whereas the G29 looks to taper out the way which I presume allows the stones in and become trapped.

What looks like the better news is on the OE website for both cars the plates looks the same, same pattern, mounting points etc so if the above is correct will possibly offer protection the BMW one doesn’t. So what we need is an M40i owner who has the time and inclination to order one (or take the punt it’s different and buy a pair) and compare them and do a like for like. If ok and they want keep and fit, if not return for a refund??

 

[raven]

The backplates don’t look the same?
That’s where the problem starts I think.

Maybe, I can not find any good pictures showing the backplates
In the diagrams look pretty much the same to me, I doubt they will be different

 

[Jim S]

You need to compare them looking at a front view.

 

[ronk]

That’s an open invite for stones and debris !
Good for airflow but nothing else.

The bottom of the backplate looks like a good way of preventing a stone dropping out :thumbsdown:

 

[Argyll Andy]

You need to compare them looking at a front view.
896B80E3-F43C-404E-A06F-85B1C859E123.jpeg

That is a shocking gap Jim, the stones can only go one way - in :thumbsdown:

I wonder if there a Supra forum to see if there’s any similar complaints or comparison pictures :lol:

 

[Jim S]

You need to compare them looking at a front view.
896B80E3-F43C-404E-A06F-85B1C859E123.jpeg

That is a shocking gap Jim, the stones can only go one way - in :thumbsdown:

And they get trapped at the bottom because the heat shield turns in at the track rod end closing the gap.

 

[Argyll Andy]

You need to compare them looking at a front view.
896B80E3-F43C-404E-A06F-85B1C859E123.jpeg

That is a shocking gap Jim, the stones can only go one way - in :thumbsdown:

And they get trapped at the bottom because the heat shield turns in at the track rod end closing the gap.

Be better not having them than that backwards design :thumbsdown:

Stupid question maybe but are they actually necessary?

 

[Jim S]

I asked my dealer if I could have the heat shields removed as they are not really necessary unless you are on the race track or driving the car very hard, causing the disks to really heat up. The dealer was not too keen to remove them. :thumbsdown:
However, I told the dealer that if I keep getting stones trapped in the brakes that I might insist on having the shields removed. So far I have not reached that point yet, but I won’t discount that option in the future.

 

[ronk]

I asked my dealer if I could have the heat shields removed as they are not really necessary unless you are on the race track or driving the car very hard, causing the disks to really heat up. The dealer was not too keen to remove them. :thumbsdown:
However, I told the dealer that if I keep getting stones trapped in the brakes that I might insist on having the shields removed. So far I have not reached that point yet, but I won’t discount that option in the future.

I think I would be more tempted to go into a Toyota dealership and discuss your options with them ?

If the Toyota part is fitted and the stone trap problem goes away, you’ll have a big stick to hit them with!

 

[Jim S]

I asked my dealer if I could have the heat shields removed as they are not really necessary unless you are on the race track or driving the car very hard, causing the disks to really heat up. The dealer was not too keen to remove them. :thumbsdown:
However, I told the dealer that if I keep getting stones trapped in the brakes that I might insist on having the shields removed. So far I have not reached that point yet, but I won’t discount that option in the future.

I think I would be more tempted to go into a Toyota dealership and discuss your options with them ?

I would want the work done under warranty.

 

[ronk]

I asked my dealer if I could have the heat shields removed as they are not really necessary unless you are on the race track or driving the car very hard, causing the disks to really heat up. The dealer was not too keen to remove them. :thumbsdown:
However, I told the dealer that if I keep getting stones trapped in the brakes that I might insist on having the shields removed. So far I have not reached that point yet, but I won’t discount that option in the future.

I think I would be more tempted to go into a Toyota dealership and discuss your options with them ?

I would want the work done under warranty.

Then think you are going to have to start banging the table.
There is an area visiting BMW tech guru - I suggest you ask for a meeting with him . I had a problem with my car albeit minor, he sanctioned a very agreeable compensation package.

 

[Argyll Andy]

I asked my dealer if I could have the heat shields removed as they are not really necessary unless you are on the race track or driving the car very hard, causing the disks to really heat up. The dealer was not too keen to remove them. :thumbsdown:
However, I told the dealer that if I keep getting stones trapped in the brakes that I might insist on having the shields removed. So far I have not reached that point yet, but I won’t discount that option in the future.

I think I would be more tempted to go into a Toyota dealership and discuss your options with them ?

If the Toyota part is fitted and the stone trap problem goes away, you’ll have a big stick to hit them with!

I was thinking along the same sort of lines but more as a stick to bear BMW with. If the Toyota brakes are basically BMW ones, have different shields but no issues then it proves the issue is with the G29 shields and you want a resolution

 

[Argyll Andy]

I asked my dealer if I could have the heat shields removed as they are not really necessary unless you are on the race track or driving the car very hard, causing the disks to really heat up. The dealer was not too keen to remove them. :thumbsdown:
However, I told the dealer that if I keep getting stones trapped in the brakes that I might insist on having the shields removed. So far I have not reached that point yet, but I won’t discount that option in the future.

I think I would be more tempted to go into a Toyota dealership and discuss your options with them ?

I would want the work done under warranty.

I agree even if that includes fitting Toyota parts to solve your issue it’s a £50k car FFS!!!

 

[Zed Baron]

Well my niece popped up to see me in her new 5 Series x-drive and it was making a hell of racket from one of the back wheels. I suspected that it was the same issue thats been experienced here and its just come back from our local BMW dealership and yes it was a stuck stone.

 

[craig3.2]

Well my niece popped up to see me in her new 5 Series x-drive and it was making a hell of racket from one of the back wheels. I suspected that it was the same issue thats been experienced here and its just come back from our local BMW dealership and yes it was a stuck stone.

Sounds like BMW's current design of the brake guard on a few models is flawed
Oh dear

 

[Sladester100]

Hey peeps

I’m back in this thread! Yay.

Does anyone have any other suggestions to remove a stone that is well and truly stuck? Or is it a case of calling BMW Recovery?

After leaving for work and getting 2 miles from home a squeal appeared - worse than last time! - it’s in the O/S/F wheel; I tried to dislodge with back and forth but nothing, got quite aggressive with my braking and even resorted to riding the “cats eyes” on my way back home on an older road where they’re big to see if the vibration helped

I then tried to flex the shield slightly (burning my fingers on the red hot rotor after my aggressive braking attempts) and I think I can see it with my phone camera right at the base being held in but can’t fathom how to remove.

Unless I take the wheel off? - where’s the jacking points?