BMW E46 M3 - Replacement Brakes

emagination

Hi alll...

I'm proud to say I recently took ownership of an E46 M3, car I've dreamed of for years!!! It's going to cost me a fortune to run, but I don't care, if I didn't do it now, I never would!

I do need to get the front brakes looked at and am wondering if anyone has any recommendations for online suppliers, or indeed specific discs or pads. I have a qualified mechanic to do the work, but was hoping to source the parts myself.

Could anyone point me in the right direction?

Thanks in advance!

kdevitt

I put a K-Sport BBK onto mine, available from Pro-Parts.ie . It was a huge improvement over stock - would recommend.

emagination

Nice pic and nice brakes...

I suppose i should have said that the front discs are warped (severe shudder through the steering wheel when braking at speed)... so I'm more looking for a disc/pad combination than a full caliper set replacement.

I know I probably should be looking at a complete big-brake kit, but would love to hear what people think?

Open to all suggestions!

kdevitt

To be honest, I found the stock M3 brakes woeful. My nearside caliper seized, so a BBK made sense. If you're just looking at replacing the discs and pads you're as well off going OEM.

emagination

Did you do anything with the rear setup, or just up front with the BBK?

kdevitt

emagination wrote: »

Did you do anything with the rear setup, or just up front with the BBK?

I just did the front as they do most of the work - will upgrade the rears if the desire to get a new car doesn't get the better of me!

Mr.David

emagination wrote: »

Nice pic and nice brakes...

I suppose i should have said that the front discs are warped (severe shudder through the steering wheel when braking at speed

Don't mean to be pedantic, but its unlikely that its due to warped discs. Its practically always due to DTV (disc thickness variation) where the discs inboard and outboard faces end up misalligned (not parallel as they should be). Then the pad passes over high spots and low spots on the disc (considering the two faces of the disc as one surface and looking at the change in thickness). This results in judder. It can be caused by lots of different things, but seen as its already an issue......just make sure you bed in your next set very carefully to prevent it reoccurring!:)

emagination

Hi Mr. David...

Are you saying that it have been due to a poor initial installation of the discs? Is this repairable? Or do I still need a need set of discs and pads and just ensure they are correctly installed and bedded in carefully?

Thanks for the replies to date folks!

Cheers

Mr.David

emagination wrote: »

Hi Mr. David...

Are you saying that it have been due to a poor initial installation of the discs? Is this repairable? Or do I still need a need set of discs and pads and just ensure they are correctly installed and bedded in carefully?

Thanks for the replies to date folks!

Cheers

It could be caused by lots of things, mainly:

a. Overheating (700degrees plus). The cast iron changes to cementite and then hardens and wears at a different rate to the unhardened section of the disc. This is unlikely, cast iron brake temp rarely exceeds 600degrees and thats when its being caned around the 'ring. However it is possible and if it has occured there will be a blue/black areas on the disc

b. Etching. When the brakes are very hot, applying them to a standstill can result in some of the pad material melting and sticking to the disc, resulting in Disc Thickness Variation giving judder.

c. Badly manufactured discs, unacceptable DTV, mass imbalance or run out.

d. Dirt/debris on the mounting face. The mounting face must be absolutley immaculate as any spec of dust will cause run out and is amplified the farther out along the disc (and away from the mounting surface) you move. This is very common so make sure you get the discs replaced somewhere that has a good rep! A piece of dirt measuring anything from about 40microns (0.04mm) upwards is problematic it is that sensitive!

e. Not bedding in the pads properly. Results in way similar to (b). Also very common.

f. Fitting pads that are not suitable for the operating temp that it will experience


Unfortunately it wont be reparable, so get new discs and pads and make sure they are mounted correctly and bed them in properly!

Cyrus

id also get someone to balance your wheels and look at your alignment, that can often manifest in shuddering under braking if its out

emagination

Great info... thanks Mr. David!

All I'm looking for is a good online source for discs and pads, OEM or otherwise!

Any recommendations?

I will certainly get the tracking/alignment checked this week too!

Cheers!

qz

Congrats emagination, pics please!

Mr.David

Well I suppose it depends on what you need. Will you simply be an enthusiastic road driver? Or will the car be getting driven very hard and used on tracks? No point spending more than necessary! Depends on budget too. The standard fit E46 M3 brakes have come in for criticism from users that subject the car to track driving etc but not a worry if its only casual to quick driving in your case?

emagination

Should only be fast-road use (under the speed limit of course)... no plans to bring it to the track just yet

Will post a couple of pics in a minute...

emagination

Photos already online... link to my Flickr account.

Mr.David

I think you should just get a new set of OEMs fitted so. If you ever feel like you do need more performance from your brakes, the easiest and cheapest place to start is to upgrade to high performance pads. But for your application I'd go with the standard fit ones!

the merchant

I had the same proble with my 525d (not an M3 unfortunately), it was like the steering wobbled violently under heavy braking.

I eventually sorted it by putting the correct pressure i the front tyres! They were at 30psi and I upped them to 34. Instant, free, result. Touch would this might be all you need.

rebel.ranter

OP - check out your brake reaction bushes. If these are worn they will give the same feel as a warped disc or un-balanced wheel.

Mr.David

You should be able to determine fairly easily if it brake related or wheel imbalance etc. by noting whether it only occurs during braking or is more general. Try driving from 40mph to 80mph on a motorway with your fingertips on the steering wheel and feel for the vibration. Judder is typically about 100Hz when braking from 80mph....good luck!

rebel.ranter

Also the wheel bolts need to be the same torque, I have heard that this can cause problems with balancing too, also if there are odd bolts used, some have a hollow in the head others are solid, this can also cause problems. Not suggesting that this is your issue, just thought it might be interesting.

emagination

Excellent... all good advice!

I would be delighted to find out that it is something more simple such as balancing or tyre pressure. More questions... Anybody know what the recommended tyre pressure for 19" CSL Wheels?

I'm going do some checking this evening, balancing, tyre pressue etc... and see what comes out of it.

@ Mr. David.. I will need to replace the front sooner than later anyways, so I think I will look RedStuff pads and hopefully get a little gain over the standard pads. If the discs do need replacing, OEM is probably the way to go for my budget at the moment!

Ta...

Peter

Cyrus

19" csls should be the same as the 19" oem, check the manual

incidentally i had the same issue when i changed my oem 19s to oem csls and it was a balancing issue

emagination

RESULT !!!

Thanks for all the posts, spent some time getting intimate with my tyres last night and discovered the front left was well down on pressure.

I topped up all tyres and instantly the shudder when breaking has gone!

I will still need to look at the front pads sooner than later, but at least I'm don't need to replace the discs just yet.

Thanks for your help lads!

Cheers,

Peter

the merchant

emagination wrote: »

RESULT !!!

Thanks for all the posts, spent some time getting intimate with my tyres last night and discovered the front left was well down on pressure.

I topped up all tyres and instantly the shudder when breaking has gone!

I will still need to look at the front pads sooner than later, but at least I'm don't need to replace the discs just yet.

Thanks for your help lads!

Cheers,

Peter

Nice one, I knew it:pac: