Help brake judder

[Brendanmck]

Originally Posted by adem.csl

What spacers have you got?
Bought my brakes brand new,fitted them run them in.day later I got vibration.spoke to the Americans who insisted I post the discs back to them.it was cheaper to sim them.while I got them skimmed I asked the tech to figure out how they got destroyed.he checked my hub run out,fine.
Checked inside my rims,fine.
Checked my 5mm spacers and found one side was actually 4.8mm cold pressed spacers were my culprit.i waited and bought lazer machines spacers.fitted them and I've had no problems in over 7 years and I e done 10 trackdays.
So I wouldn't rule out a tolerance issue either between hub n bell or bell and rim.

Thanks for all the advice il get stuck back into the issue and with a bit of luck get to the bottom of it il update you on my progress and thanks again.

[NZ_M3]

Brake judder is almost always caused by incorrect bedding in, so you have an uneven pad to disc transferance which you can't physically see but feel through steering feedback in juddering.

Of course assuming the kit was fitted correctly and measured.

You also can't bed in racing compound on the road ... anyone that claims to be able to do so doesn't know what bedding in is.

Having a bad front wheel spacer can also cause that. If enough clearance take them off and test.

[select]

Yes especially at this stage i would remove the spacers and see if the problem persists.
Also check if your wheel bearings are shot while at it.
My take is that either thing is the problem.. braking loads more force on the spacers and bearings.

[adem.csl]

[quote=NZ_M3;201028]Brake judder is almost always caused by incorrect bedding in, so you have an uneven pad to disc transferance which you can't physically see but feel through steering feedback in juddering.

Of course assuming the kit was fitted correctly and measured.

You also can't bed in racing compound on the road ... anyone that claims to be able to do so doesn't know what bedding in is.

Having a bad front wheel spacer can also cause that. If enough clearance take them off and test.[/QUOTE


He says he skimmed the discs and fitted new pads.im assuming he has a road compound pad and not an rs29 type pad
Brake judder can be caused by couple other factors. over heated discs or seized calipers.if you over heat the discs and don't let them cool e.g you hammer your brakes then stop at the light with your foot on the pedal you cause a heat spot around the pad which causes that part of the dos to soften and warp.another attribute is slamming on the brake so hard you leave the pad on the surface of the disc.ive seen this too.boiling hot discs through a cold puddle.puddle big enough to touch the discs that is.or build up of rust between hub and disc.
There is a point made here!if you have debris from the brake pad left on the disc say for example you sat with your foot on the brake whilst boiling hot,you may have left a layer from the pad on the disc.you may and I say MAY be able the make out the outline of the pad shape on the disc.if soo it's been possible to sand off the debris left by the pad on the disc.although in my opinion not highly likely.

Removing the spacers and trying it like that won't cure the issue.once the discs are warped they are warped.sorry.response to selects post.

[adem.csl]

These are only what I've taken from my experience being a mechanic for 25 years
They are my opinions and not facts.im only offering diagnostic advice
I hope you get it sorted and the help from techs on this forum serve as valuable info
Good luck dude.

P.s found this light bit of reading.i meantioned everything I this link before I reading it.
https://mycarneedsa.com/blog/causes-...-how-to-fix-it

[adem.csl]

image.jpg

This is one of my customers cars from a couple weeks back
He took it to a tyre and brake shop on the high street.they fitted him cheap pads and discs
He wanted to save a bit of dough
They didn't clean the hubs of rust and debris.it warped in 8 weeks.i had to clean this all down properly and remove all the high points.fitted new pads and discs problem solved

[adem.csl]

image.jpg
This is a rusty high spot where water has gone through a hole and settled behind the disc.not cleaning this off PROPERLY will cause intolerance in the disc.not long after you get vibration cos it won't run true

Hope that helps in some form
I know a Mercedes hub is not the same as a Bmw hub but you get the idea

[select]

Adem, no problem im not a car mechanic and i certainly dont have 25 years of experience. Im just another csl drug addict.

But.. considering he has changed pads and had his rotors skimmed that certainly leaves me to think the problem is probably elsewhere. And when i read that he has spacers installed it is a good idea to remove them just to see if they were the issue. If they are cheap versions or not of hub-centric type they certainly can cause steering wheel wobbling. I dont know if wheel bearings can cause it too but i think if they are shot enough they can?

[adem.csl]

Originally Posted by select

Adem, no problem im not a car mechanic and i certainly dont have 25 years of experience. Im just another csl drug addict.

But.. considering he has changed pads and had his rotors skimmed that certainly leaves me to think the problem is probably elsewhere. And when i read that he has spacers installed it is a good idea to remove them just to see if they were the issue. If they are cheap versions or not of hub-centric type they certainly can cause steering wheel wobbling. I dont know if wheel bearings can cause it too but i think if they are shot enough they can?

You are right about the spacers cos as not my early post I said of the problems I had with cheap cold pressed spacers.now although they were temporary to get me home for weekend they caused a lot of damage to my new brakes.
Stoptech only do bbk 380mm kit for e46 m3 and not Csl so my problem was the et setting of the rims as Csl is 3mm shy of the m3 et setting ,my wheels touched the calipers and caused damage to my rims and brand new calipers.so I had to go halfords to get cheap 5mm spacers to make up clearance so I could get the car home.
I'm not saying anyone's opinion is wrong I'm only saying my advice is an aid to diagnosis and in a sense is not fact based because I'm a practical mechanic not a technical mechanic.in the sense I know what's wrong and what I'm doing but I'm not technical all numbers n figures about it.

I don't seek to argue with anyone so I just choose to add my opinion and hope it helps guys out.

[select]

That sucks to hear about your wheels and brakes.. what a pain in the

Originally Posted by adem.csl

I don't seek to argue with anyone so I just choose to add my opinion and hope it helps guys out.

Its all in good spirit, i didnt mean to start bickering with you. You certainly know your stuff, so i am glad you are sharing your knowledge.