Z4M "Rumbly" Brakes

[pilchardthecat]

Hello

I've noticed a rumbliness about my brakes under hard braking. Can't really notice it under normal conditions, and hard braking is still effective, but doesn't have as much feel as i would like because of the rumbliness getting in the way.

[playalistic]

I get it sometimes. Usually just deposits on the discs or the grooves are filled with gunk. A good clean can sort it out!

[paulmon]

pilchardthecat said:

Hello

I've noticed a rumbliness about my brakes under hard braking. Can't really notice it under normal conditions, and hard braking is still effective, but doesn't have as much feel as i would like because of the rumbliness getting in the way.

What is the wear like on the pads/disk?

Could be material build up, corrosion or knackered disks/pads. If you have lots of pad material left then find yourself a nice quiet stretch of road (industrial estate or something that has very little traffic) accelerate upto 70 mph and then brake very hard but dont stop. Repeat this process about 6 or 7 times. If its material build up or corrosion this should sort it. Remember to let your brakes cool down throughly before stopping and applying the hand brake.

I had a very similar problem and the rumbling was only evident when braking from 70+ It turned out my disks were warped (not actually warped but not true) and I got new disks and pads done under warranty but only after jumping up and down and lots of shouting about how a set of disks on a performance car should not be faulty after 11000 miles.


P

[CarbonBlackM5]

Sounds like the problems I have been having with mine. I have new discs and Powerflex reaction bushes fitted but its still there. I might get the pads checked next.

[Porscheplayer]

playalistic said:

I get it sometimes. Usually just deposits on the discs or the grooves are filled with gunk. A good clean can sort it out!

+1

[api330]

They all make quite a loud rumbling noise when using hard when hot, (very loud when using very hard) same as csl and m3's as long as you have no juddering i would think they are ok, its easy to look though wheels and check pads are ok,

[ecain63]

Before you go off and spend a tonne on discs could you clarify whether they are just noisy or are vibrating? If they are whiring then it might just be the normal sound of the cooling ports / holes passing the bads when hot. If they are vibrating then its either; nackered control arms / reaction bushes, misaligned pads or warped discs. The discs don't warp so to speak but I've they were hot when parked up then they can suffer uneven expansion under heavy use due to uneven cooling. Do the 70mph to 5mph x 7 bed in process and if you have no joy get the arms / bushes checked. Then if that doesn't cure it then its time to get your wallet out.

Eddie

[pilchardthecat]

Thanks all. I'm going to try giving them a clean at the weekend as the holes are full of crud.

I think there is some vibration but it's only really evident at high speed under hard braking. Not sure it's bad enough to warrant early replacement though.

[Cheburator mk2]

ecain63 said:

Before you go off and spend a tonne on discs could you clarify whether they are just noisy or are vibrating? If they are whiring then it might just be the normal sound of the cooling ports / holes passing the bads when hot. If they are vibrating then its either; nackered control arms / reaction bushes, misaligned pads or warped discs. The discs don't warp so to speak but I've they were hot when parked up then they can suffer uneven expansion under heavy use due to uneven cooling. Do the 70mph to 5mph x 7 bed in process and if you have no joy get the arms / bushes checked. Then if that doesn't cure it then its time to get your wallet out.

Eddie

Err, the Z4M has a completely different front suspension from the E39/E60... So no front control arms or reaction bushes to go wrong...

The discs will always be parked hot when you think about it...

The Z4MC/R has brake assist, which means that the brakes make rumbling noises when using them really hard. It is all in the User Manual... Alternatively it could be pad deposits on the discs - brake really hard a couple of times - that should get rid of them ...