M40i brakes - design flaw uncovered
- Thread starter Jim S
- Start date
I'm the latest (but won't be the last) victim of this issue. Drove to work this morning, halfway through, the noise appeared very loud and high pitch. Arrived at office car park and called bmw roadside assistant. They came and loose the disc to free the stone. 
BigDave
Member
Just been looking into this stone trapping issue, and did a bit of youtube,ing and found this video on how to swap out the brake pads on a MK5 supra, the same brakes as ours,,,
https://www.youtube.com/watch?v=wNK3Tp412Pg&t=322s
If you look closely in the vid it shows the top part of the backing plate,, and its the same as the BMW version, so obviously the answer to does the Toyota backing plate fit,, yes it most likely will, but it wont make any difference...
:x 
https://www.youtube.com/watch?v=wNK3Tp412Pg&t=322s
If you look closely in the vid it shows the top part of the backing plate,, and its the same as the BMW version, so obviously the answer to does the Toyota backing plate fit,, yes it most likely will, but it wont make any difference...
:x 
Scubaregs said:PeterFree said:Sat by the side of the road as I type with same issue waiting for roadside assistanceā¦.
PeterFree said:Sat by the side of the road as I type with same issue waiting for roadside assistanceā¦.
Twice in a minute, that is unlucky........
Stop it....... :lol:
PeterFree said:Sat by the side of the road as I type with same issue waiting for roadside assistanceā¦.
PeterFree said:I call mine Fat Bast**d as despite measuring it before I bought it, he won't fit in my garage!
Could this be payback time Peter? :lol:
Hopefully youāre not waiting too long. I carry a 9 inch screwdriver for such incidents, worked each time so far
Scubaregs said:Argyll Andy said:I carry a 9 inch screwdriver for such incidents, worked each time so far
You use a nine inch screwdriver on fat B'stards?
Ask no questions, Iāll tell you no lies
I have learned to live with this. Drive back and forth a few times braking sharply as you stop to change direction. Should free it but not gauranteed.
Lol. Very nice chap named Charlie turned up within 20 mins, whipped the front wheel off and got two stones out from between heat shield and disc and I was on my way again within an hour.
Will be calling BMW tomorrow to log the issue as well though
Tried to post pic but failed :-/
Will be calling BMW tomorrow to log the issue as well though
Tried to post pic but failed :-/
Hi guys,
Hope everyone is well. I check back here now and again, was already great forum
Just to confirm since I now own a Supra, this has happened to me twice in 8 months over 3500 miles Brakes and suspension are all stamped with BMW logo and part numbers.
Both times the wheel had to come off, couldn't dislodge it by reversing. Super embarrassing, car turned into a head turned for all the wrong reasons
Car is on axle stands at the moment, so this reminded me to bend the stone protectors back a little.
Hope everyone is well. I check back here now and again, was already great forum
Just to confirm since I now own a Supra, this has happened to me twice in 8 months over 3500 miles
Brakes and suspension are all stamped with BMW logo and part numbers. Both times the wheel had to come off, couldn't dislodge it by reversing. Super embarrassing, car turned into a head turned for all the wrong reasons
Car is on axle stands at the moment, so this reminded me to bend the stone protectors back a little.
I keep a scissor jack, wheel nut spanner and socket, plus a long screwdriver in the boot and remove the stone myself if and when it happens. Been a while now. Seems like when the tyres wear a bit and lose their āstickinessā the problem occurs less frequently. 
McHaggis69
Member
For info
I had my car in at BMW for its MoT within the last two weeks and raised the matter with them.
"Its not something we've heard of and there are no recalls..."
I should have pointed them to this thread.
I've owned dozens of cars and this Z4 is the only one I've ever experienced stones getting trapped and its happened twice!
I had my car in at BMW for its MoT within the last two weeks and raised the matter with them.
"Its not something we've heard of and there are no recalls..."
I should have pointed them to this thread.
I've owned dozens of cars and this Z4 is the only one I've ever experienced stones getting trapped and its happened twice!
McHaggis69 said:
They know very well about the problem. It happened to me 5 times in the first 1,270 miles of ownership in 2019. I even wrote directly to Mr Grieve, UK MD, and reported each occasion to my dealer who passed on photographs of the problem to their Technical Department in Germany HO.
Poor show from BMW. :thumbsdown:
Jim S said:McHaggis69 said:
They know very well about the problem. It happened to me 5 times in the first 1,270 miles of ownership in 2019. I even wrote directly to Mr Grieve, UK MD, and reported each occasion to my dealer who passed on photographs of the problem to their Technical Department in Germany HO.
Poor show from BMW. :thumbsdown:
How did you write to me grieve? Can you pm me the email address? I wish to do something similar.