3

We recently got BMW 760li M performance G12. It has the M blue brakes system, see image below.

When driving in extreme mode (it is for officials, almost always in rush mode) the brakes do not perform as well. They get so hot and smoke, then the brake pedal drops.

We were suggested to replace brakes with Brembo products. But a quick search showed they don't do brakes for this model. Contacted BMW, they said the current brakes are the best they have, and would not advise to put third party parts and if we do we lose the warranty.

Losing warranty is not a concern, so the question*:

How do I fix this issue, what can I do about the overheating, any advice?


*Also, posted at bimmerfest forum, no response yet.

enter image description here


Edit: Finally engineers established that the brakes were faulty, and replaced with new original brakes. The issue is fixed. I am closing this post, as it now seems off-topic. Thank you for all the comments.

  • Unfortunately the supply question is off topic for this site. You may be able to edit your question to be salvageable by asking a straight forward How do I fix this issue? or What can I do about the overheating? – Pᴀᴜʟsᴛᴇʀ2 Nov 24 '17 at 22:00
  • @Pᴀᴜʟsᴛᴇʀ2 Still new on this site, sorry, post updated. Yes, you are right at the end of the day I want to fix this issue. So this post is not about supplier recommendation. Thanks. – zx8754 Nov 24 '17 at 22:50
  • Does extreme mode somehow lengthen the push rod that goes into the master cylinder for quicker brake grab by any chance? No clue about the blue brakes system, but if that push rod is applying pressure to the master cylinder position when you don’t want to brake then they’ll over heat like that – sjfklsdafjks Nov 24 '17 at 23:46
  • Completely on topic now ... thanks for saving your own question. I'd suggest it's not the brake calipers which are at issue, but the friction material and rotors which are causing you heck. Also, these parts will not void the warranty, because they are wear items. Now, what to do or replace them with is another story. – Pᴀᴜʟsᴛᴇʀ2 Nov 25 '17 at 0:57
  • 1
    If you replace the caliper, I might see that ... not the rotor/pads portion of it. At least that's the way it works in the States. Maybe someone in the UK can better qualify it. We have consumer protection laws (these protect aftermarket manufacturers as well) here in the States which prohibits vehicle manufacturers from pulling that kind of crap. I'd have to think it should be somewhat the same in the UK. I've done some internet reading on the subject, but cannot find anything definitive. Maybe someone else from the UK can chime in. – Pᴀᴜʟsᴛᴇʀ2 Nov 27 '17 at 15:15
3

Engineers established that the brakes were faulty, and replaced with new original brakes. The issue is fixed.


Thank you for all the comments.

1

It's worth noting for anyone else that visits this question:

If your brakes are overheating during quick/spirited driving (and there aren't any underlying issues as with OP's brakes) there are several things you can try to solve the issue.

  1. You can install high performance brake pads. These pads will continue to provide stopping power up into higher temperature ranges, though you will usually have to make some kind of compromise (ie they may produce more dust or noise, or they might wear your rotors more than other pads). This is why brakes on race cars are usually loud/squeaky - they want the highest possible temperature rating, and they don't care if they make a lot of noise.

  2. You can install ducting on the front bumper that will route air into the CENTER of the front brake rotors, which will help keep the system cool. It's important to route the ducting to the center of the rotor because most rotors are already ventilated (they have an air gap in the middle of the rotor), so directing the duct towards the center will aid in cooling the entire rotor, whereas if you direct the ducting to the caliper or any specific part of the rotor, it won't cool as efficiently. It could also over-cool that spot on the braking system which can lead to warped brake discs.

  3. You can flush your brake's hydraulic system and re-bleed with a high temperature DOT4 or DOT5.1 brake fluid (though this fluid will absorb moisture more quickly than standard 'street' fluid, so you will need to flush it more often).

  4. If none of this solves your issue, you may want to look into installing a big brake kit (BBK) from a reputable manufacturer (ie Brembo, StopTech, Sparta Evolution). BBKs are typically only necessary for people who drive their car on the track, where the hard and repeated use of the brakes doesn't allow the system time to cool between braking events. BBKs are engineered to transfer heat more efficiently than the OE braking system, and have a higher thermal capacity such that they can stay hotter for longer without compromising braking power.

  • Thank you for the answer, in my case, above 1,3,4 points wouldn't work, as the car was brand new, there were no alternative BBKs available at the time of writing of my question. 2nd point might be worth considering. Agree, these can be useful advice for other visitors. – zx8754 Apr 27 '18 at 8:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.