Warped discs issue

[outrun]

I've been experiencing a bit of judder under braking and a little binding at slow speeds. Put it down to lack of use over the winter causing some surface corrosion (even though it was garaged the whole time) so put in into my local indie for a deglaze and skim. He tells me that the front discs are warped and called my Stealer to enquire about a warranty fix.

Question is, although i'd love them replaced under warranty, i doubt they'll buy it as they are wear and tear items. Anyone else had this issue or similar? Think i'll get them to look at my squeaking handbrake issue as well.

Ta

 

[Smokin]

After jeeper's fix, make SURE they cleaned the disc thoroughly before trading them out. If it's under warranty, go for it. I had my first brake job done under warranty in my 325Ci--saved me lot of money as they change discs when they change pads at the dealer.

 

[Stealthyman]

I've been experiencing a bit of judder under braking and a little binding at slow speeds. Put it down to lack of use over the winter causing some surface corrosion (even though it was garaged the whole time) so put in into my local indie for a deglaze and skim. He tells me that the front discs are warped and called my Stealer to enquire about a warranty fix.

Question is, although i'd love them replaced under warranty, i doubt they'll buy it as they are wear and tear items. Anyone else had this issue or similar? Think i'll get them to look at my squeaking handbrake issue as well.

Ta

As one of the "experts" on this forum you ask a very strange question :? . You will get "surface corrosion" ie RUST on the disks within 2 hours of washing your car. Under 1 mile of driving & using the brakes clears this! Warped disks on any BMW are virtually unheard of in 2009 - it was common on RS Fords in 1988+ though....

As for the "squeaking" handbrake - does it "squeak" on handbrake spins or just when you pull the lever up? Suggest some WD40 or grease on the cable mate :roll: .

 

[cj10jeeper]

I don't believe for one moment that the discs are warped. I went down this route of investigating after I suddently got some brake judder on just run in new performance discs and from articles and as stealtyman indicated they don't warp these days. I measured run out and all was perfect, just had to clean the face and rebed them correctly. Perfect ever since

Sure if the dealer will replace them go for it, but I'd not be thinking about skimming or shelling out for new until I'd seem them on a dial gauge as out of spec.

 

[pvr]

Also, on an M you have the brake tensioning so it applies the brakes briefly. My surface rust after washing is gone before I leave the drive.

 

[Beedub]

doesnt sound right really, im sure you could warp these quite easily but im sure it would take some big stopping repeatedly, last week i did my first trackday of 09, after 6 sprint runs doing 100mph down to 15mph the brakes where fine, they did smell alittle but they were fine, infact of the day the most impressive part of the car was the brakes which are apparently known to be crap, so do some other checks or take her into the dealer and see what they say, im waiting eagerly.


byron

 

[mmm-five]

I've not warped a disc in over 100 track events in any of my cars - modified Corrado VR6, 3.8 M5, 3.6 M5, Z4MC.

I've had grumbling and wobbling brakes after an event and for about 200 miles afterwards, but that was pad material on the disc or loose wheel-bolts

The standard road pads are not much use though and something like EBC Redstuff, Ferodo DS2500/3000, Pagid Blue, etc. will help.

Also some tuition on how to brake properly on track can help too - basically get your heaving braking done at high speed and lift off the brakes, rather than pressing harder & harder to slow down.

 

[Shipkiller]

basically get your heaving braking done at high speed and lift off the brakes, rather than pressing harder & harder to slow down.

Which leaves the car much better balanced (weight distribution) for your turn-in....

 

[Wondermike]

I currently have an identical situation on my SLK (OK not a Z4M but very similar perforated discs) and it has happened due to lack of use in cold weather. It goes in to the Merc garage in a week and a half to see what they can do.

 

[outrun]

I've been experiencing a bit of judder under braking and a little binding at slow speeds. Put it down to lack of use over the winter causing some surface corrosion (even though it was garaged the whole time) so put in into my local indie for a deglaze and skim. He tells me that the front discs are warped and called my Stealer to enquire about a warranty fix.

Question is, although i'd love them replaced under warranty, i doubt they'll buy it as they are wear and tear items. Anyone else had this issue or similar? Think i'll get them to look at my squeaking handbrake issue as well.

Ta

As one of the "experts" on this forum you ask a very strange question :? . You will get "surface corrosion" ie RUST on the disks within 2 hours of washing your car. Under 1 mile of driving & using the brakes clears this! Warped disks on any BMW are virtually unheard of in 2009 - it was common on RS Fords in 1988+ though....

As for the "squeaking" handbrake - does it "squeak" on handbrake spins or just when you pull the lever up? Suggest some WD40 or grease on the cable mate :roll: .

Mate, i'm quite aware that the discs suffer surface corrosion but it should be long gone after 200 dry miles. You're also not aware that all ZMs seen to get suffer from a squeak when you get out if the handbrake is applied. It's something to do with floating handbrake shoes or something, can't remember exactly.

Thanks all for the comments, it's been round the Nurburgring and that didn't warp the discs. I'll let BMW have a look i think as they'll probably replace the discs as they won't show up on a diagnostic computer so won't know what else to do!


I'll post an update once BM have given their verdict. Fingers crossed it's new discs under warranty!

 

[Minero]

Outrun,

I've had my front discs (warped) replaced twice under warranty, so please go for it.

 

[outrun]

BMW have now admitted that the nearside disc is warped but they are suggesting only changing tha disc under warranty! Is this as mad as it sounds, should they not be replacing the front pair? Please advise...

 

[Smokin]

If only one is warped, they'll only replace the one.

 

[outrun]

eh but that would surely leave uneven breaking? i'm going to have a good go at getting them both replaced then send it over to my local independent for some green stuff orsimilar fast road pads. fingers crossed....

 

[davidch]

If only one is warped, they'll only replace the one.

No, BMW would replace both!

 

[Stealthyman]

It is commonly accepted within the motor industry that anything regarded as effecting safety aspects on both axles should be replaced as a matched pair. This includes discs, pads, shock absorbers & tyres. Even "Kwik-Fit" do this.

 

[davidch]

Even "Kwik-Fit" do this.

Bloody hell...Them do something right!

 

[mmm-five]

They're probably quite happy to replace both, however they'll insist that only one side is covered by the warranty.

There is no safety issue then, it's purely a cost consideration - i.e. not their problem anymore.

 

[cj10jeeper]

It clearly states in the TIS manual that it is acceptable BMW practice to change just one disc and if done under warranty the dealer will only be able to claim warranty costs and labour for 1. I read it only the other weeks ago as I was working on changing my own discs and pads. Clearly if the other side were worn the a very different matter an that would be changed under normal service work.

Pads and tyres I agree.

 

[outrun]

SUCCESS! I now have a new set of front discs under warranty. They wanted to replace only the nearside one but as with most things it's not what you know but who you know and a couple of phone calls later, Hey Presto, a new set of discs Sir.

It's now gone off for a set of EBC Red Stuff pads (seems silly not to get new pads at the same time), a custom ICE install which i'll tell you all more about when i get the car back and do some photos and a new set of Vredstein Ultrac Sessantas.

Here comes summer!