New front Discs Required

Road Trip

Member
Lancashire
Getting vibration through the wheel on medium/heavy braking. Took the front wheels off and turned the discs by hand through the pads. They do catch the pads at a particular point so guess they must be warped? Can't understand why and am dissappointed because I am not a heavy braker at all, it's not my style of driving.

If I do need 2 new discs can anyone point me in the direction of a good supplier? Thinking of doing it myself so would also like to know the torque settings for the bolts?

Also, my pads are probably only about half worn (again due to my driving style) so was thinking about fitting new discs and leaving the original pads in. Any thoughts on this?

Any help will be much appriciated.

Thanks folks :)
 
New discs means new pads I'm afraid otherwise you will bugger up the new discs as the pads will have worn to suit the old discs.
 
Not sure if you are still in warranty. BMW replaced my front discs and pads under warranty for the same problem.
 
Eurohooner said:
Not sure if you are still in warranty. BMW replaced my front discs and pads under warranty for the same problem.

I've got a 3.0si and it's got the same problem. Only bought it from te stealers about 2 weeks ago so luckily under warranty.
 
I don't get this, I've got a 450bhp+ z4m which sees the track 5-7 times a year which is still on the original stock pads n discs, I've never had any warped discs, no vibrations on braking, I can promise you Ive seen my brakes go bright blue on one occasion, what I'm getting at is surely u must have an issue?? Maybe thers just deposits on the discs?? Try some repeated hard stops from 80mph. Maybe the calipers arnt releasing the pads properly causing overheating?? Look into this as this isn't normal for your driving style. Just my 2p worth.

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srhutch said:
New discs means new pads I'm afraid otherwise you will bugger up the new discs as the pads will have worn to suit the old discs.
My understanding as well... :(
 
if its very light and the discs are a good thickness there is a system where they machine them back flat whilst still on the car, i would only consider this if it was a very small amount of metal required to be machined off to bring them back to flat
if in doubt fit new discs.
you dont drive through deep pudles do you? or live close to the motorway? if you get the discs realy hot then park the car the bits shrouded by the calipers and pads cool at a different rate than the rest this can cause warpage, always best to do a cooldown lap if you know what i mean
also if these are not the origional discs and the replacement were not bedded in properly (long even braking to get the disc evenly blue) it could have been unevenly stressed
 
i got a set of front discs and pads from eurocarparts,imo it was a very reasonable price :thumbsup:
 
alfamale said:
if its very light and the discs are a good thickness there is a system where they machine them back flat whilst still on the car, i would only consider this if it was a very small amount of metal required to be machined off to bring them back to flat if in doubt fit new discs.

Never one to skimp on safety stuff - go for new discs and pads. :thumbsup:
 
I had replacement front discs at about 20k as they were well worn, they wouldn't give me anything towards them :thumbsdown:
 
I know what you mean. When mine started vibrating I did all this including some hard stops after the 1/4 at Santa Pod but it didn't work and the new discs did work.

I got the car second hand so might be from previous use. The dealer said it was from sitting on the brakes at traffic lights etc which sounds like bull to me. I have tracked all my previous cars and never had the problem so not sure if some of the M brakes are just that way? New discs have been round the Ring and general wear and tear driving and no problems at all since they were put on.


Beedub said:
I don't get this, I've got a 450bhp+ z4m which sees the track 5-7 times a year which is still on the original stock pads n discs, I've never had any warped discs, no vibrations on braking, I can promise you Ive seen my brakes go bright blue on one occasion, what I'm getting at is surely u must have an issue?? Maybe thers just deposits on the discs?? Try some repeated hard stops from 80mph. Maybe the calipers arnt releasing the pads properly causing overheating?? Look into this as this isn't normal for your driving style. Just my 2p worth.

Sent from my iPhone using Tapatalk
 
Thanks for all the quick feedback chaps :thumbsup:

I totally agree with your comments Beedub. I've never had problems with brakes on any other car I've owned.

Looks like new discs and pads then.

Anyone know how much to expect from dealer vs DIY?
 
Europarts ( http://www.eurocarparts.com/ecp/p/Car-Parts ) show between £55 and £70 for front pads and £170 for discs (all of course x2). Lots of other options depending on make/quality etc. Not sure what time a dealer woulds take to fit these but reckon on a couple of hours charge - £150-£200. Easy to do yourself.
 
Road Trip said:
Getting vibration through the wheel on medium/heavy braking. Took the front wheels off and turned the discs by hand through the pads. They do catch the pads at a particular point so guess they must be warped? Can't understand why and am dissappointed because I am not a heavy braker at all, it's not my style of driving.

If I do need 2 new discs can anyone point me in the direction of a good supplier? Thinking of doing it myself so would also like to know the torque settings for the bolts?

Also, my pads are probably only about half worn (again due to my driving style) so was thinking about fitting new discs and leaving the original pads in. Any thoughts on this?

Any help will be much appriciated.

I understand where Ur coming from I have posted a few replys bout
this subject before and don't get it! :headbang: Iam on my 4th set of front brake discs, all paid for by BMW but still now get some vibration when braking! What I find is when the brakes are cold there is no vibration only when they are warm or hot does it vibrate through the steering wheel like driving through some twisty b road lanes and giving it some welly! But I think the original pads are to blame and may-be not the discs. Just wish the brakes could match the engine!



Thanks folks :)

I
 
I'm with the dealer on this one. A pound to a penny says the discs won't be warped but they will have an uneven build ip of pad deposits. And the best way to get that is sitting stationary with your foot on the pedal when everything's nice and hot because you've just used the brakes to come to a halt. The irony is that if you're not hard on the brakes and brake gently but for longer it probably exacerbates the problem. To be honest, I can't believe how often people manage to get discs replaced under warranty "because they're warped".
 
alfamale said:
if its very light and the discs are a good thickness there is a system where they machine them back flat whilst still on the car, i would only consider this if it was a very small amount of metal required to be machined off to bring them back to flat
The floating rotors on the Z4M can't be machined in any circumstance, whether on the car or on a brake lathe, as the rotor hat is not rigidly attached laterally to the brake rotor (hence the "floating" part of the design).
 
Never had a warped disc in my life - but have had plenty of 2nd hand discs from friends who've stumped up for new discs after 1 track day.

I used to just drive on them for a few hundred miles after the track day and they'd be back to normal. Aftermarket pads can help to stop these uneven deposits, as can a bit of braking instruction (i.e. hard, early, fast - and easing off, rather than softly, softly, bugger, bugger, slam).
 
Thanks again guys :thumbsup:

Had the wheels off today and there isn't much of a high spot at all really.

Gonna nip out tomorrow and see if a bit of "proper braking" makes any difference.
 
Have a look at this thread over the issues I had under warranty. I proved in the end the discs had 40% life still in them, and BMW gave me 40% discount on mey discs and pads.

http://www.z4-forum.com/forum/viewtopic.php?f=9&t=18277

I did however change the BMW pads for Hawk pads a few weeks later, and I'd go for them to be honest, as much better, and hardly any brake dust.
 
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