E39 rotor life expectancy

[Haz77 0]

Hi,

Had my E39 530 m-sport for 5years - 60'ks now & in that time ive had;

The rotors it came with skimmed,

New rotors fitted in feb '15 (20'ks ago) supplied by a reputable aftermarket BMW parts supplier,

Now im told by the workshop that these now have run out which is causing a shake & need either skimming or replacing,,,

My driving is probably slightly harder than Norman in his Holden cruise but im certainly not track racing or even thrashing around the roads or even braking hard out ever.

Im running hard pads (no dust so I think ceramic?) & they have barely worn in the 60'kms ive had the car, Im told there is no obvious sign of a problem with the pads,

My understanding is that BMW's run hard pads & soft rotors as this is the most efficient set up but is this amount of wear / regularity of warping to be expected??

The workshop are saying the pads must be to hard & I should skim the rotors & fit softer pads,

Its going to cost $2-250 all up to skim the rotors in place + pads if I change them, effectively they are scrap as is so since this is a lost less than replacing I may as well go for it, even if they warp again in 10-15'kms due to being thinner.

What do you all think, is there something else I should be looking at??

Cheers.

[aja540i 1906]

I had a set of reputable aftermarket discs on my vr4 that kept warping and on inspection the original casting and machining process had been done wrong so the thickness of the metal was not consistent around the disc, this meant that as soon as they got a bit warm they went taco shaped and tried to shake the car to pieces. Get a specialist to look at the discs, you may be able to go back to the supplier for a refund.

I have had BMW discs and pads on my e39 540i for about 7 years with no problems.

PS the aftermarket sh1t was EBC.

[Young Thrash Driver 1020]

FCPEuro will do you a full set in several different brands- including genuine BMW- for between USD200 and 360odd. Suggest it not really worth machining old rotors.

20km from a set of rotors is bollocks. Are they actually warped or do they just have deposit built up on them in odd places?

[Neal 544]

Probably done 600,000 kms in BMs and have always found OE rotors and OE pads the best long term combo. Tried skimming a couple of times but like your experience only was effective for 20,000 km. Down side is brake dust on OEM but never had shaking or out of balance type behaviour.

Edited July 1, 2016 by Neal

[Haz77 0]

Thanks Guy's.

To say Its not worth skimming the rotors when I would prob get another 20'kms out of them is a bit of a double negative to me when the alternative is to scrap them & replace both the rotors & pads, why not just skim them, kill them & then ditch them & the pads & start over, especially if the new set will be $2-300usd + fitting.

waiting to hear what the supplier of my rotors thinks of this situation, the rotors where checked when fitted & had zero run out when new.

[Neal 544]

I've always treated them as a safety item and look for cost savings elsewhere like coffee addiction for example.

Last set of rotors where $1800 by contrast.

[aja540i 1906]

Something has caused the rotors you have to warp, if you are not driving hard then there is a good chance it is a manufacturing defect, if it is then skimming them will not solve it and you will end up scrapping them anyway. I would try to get some or all of your money back and put genuine discs and pads back on. A defect in the casting or machining process might not show as run out but can still cause warping.

[Allanw 1071]

When does the shake happen?

Are the rotors REALLY warped, or do you need front suspension bushes?

We've put 40K on our 525i, since I did the front bushes for a shake we had - haven't touched the brakes at all! The bushes LOOKED perfect, but the front end is tight since the rebuild.

[BlackAngel 60]

If you do get them skimmed - check if their skimming equipment does concentric cuts or spiral cuts.

My bake guy has a $9k machine that does concentric cuts by stepping between diameters rather than the spiral you'd get on a lathe type machine - better bedding in apparently.

BTW, does anyone know what the minimum thickness spec is?

Edited July 3, 2016 by BlackAngel

[Haz77 0]

Thanks guys, food for thought,

I actually told them It had a loose control arm bush as from past experience that is what it felt like, shaking through the steering when braking & cornering, they said they checked all & no problems, then they measured the disks & they have run out, I didn't ask exactly how much. 20'000kms ago when they fitted them they also measured them & they where fine.

I am disappointed as I specifically went with parts from a trusted BMW specialist supplier rather than the other options available & they wernt the cheapest on offer so what you are telling me to do is actually what I did an the result is warped / failed rotors.

I know where you are coming from but sorry, dont agree that just because they will warp again at some point makes them some how inherently unsafe, continuing to drive the car with warped rotors of course is unsafe but not using a part or repairing a part just because it will fail in a non critical way pretty much means dont own a car to me!

If I am replacing them I would examine them for defects but unless it was blindingly obvious what is wrong then I know I'd be flogging a dead horse as who am I to know the tolerances or spec's for the part,,,,

Possibly the supplier can sell me pads suited to these rotors so I can skim them & at least get some value out of them as it seems to be the consensus that the pads have caused the problem.

[jom 98]

I consider rotors a consumable item - I usually need to fit (because of min thickness) new rotors every two pad changes. I rather like my brakes to work...

[Haz77 0]

Supplier is also saying 2pads = 1 rotor, they are recommending replacing both rotors & pads prob looking at $1000.00 installed.

will take a look at them asap, measure the thickness, look for anything obvious wrong with them & see what pads Im running now before I go charging in to a 4 figure bill.

[Haz77 0]

OH!

Ive contacted FPC as they dont list a 530 or a motorsport so will see what they offer.

I was going to skim them at $80nz each because I thought new rotors would be at least $200nz each.

Out of interest is swapping them just a case of unbolt the calliper, remove the rotor fixings, swap, re fit calliper & wipe it all down with brake cleaner?

[jom 98]

Even buying in NZ I can get all four corners (pads and rotors) for way under 1k, using brembo rotors and oem pads.

[Haz77 0]

Even buying in NZ I can get all four corners (pads and rotors) for way under 1k, using brembo rotors and oem pads.

Minds giving me your suppliers details?

[BlackAngel 60]

I use a DTI to check run out on new rotors. They should be good enough but sometimes rotating them a bit on the hub gets them even better.

[jom 98]

Minds giving me your suppliers details?

It is an E36.... but Dealer or Milland. Looking at FCP they are even cheaper

[Haz77 0]

Even buying in NZ I can get all four corners (pads and rotors) for way under 1k, using brembo rotors and oem pads.

$1000, fitted by a workshop that is, allowing for Postage and 2-3hours labour,

BMW Brake Kit Front (E39 530i 540i) - Brembo/Akebono 34116767059KT1

Rotors , pads, sensors, delivered $595nzd, throw in a couple of hours labour and that's pretty much $900.

Skim mine $250, let the pads do there worst, maybe 10'kms - 1 more year out of them, pretty much the same kms per $.

Will check mine out first, prefer to know what Im dealing with before I start dealing out the $$'s

Edited July 5, 2016 by Haz77

[Haz77 0]

So do those $200 Meyle/Akebono kikts pass the grade for worth buying or are they a waste of money?

And I dont mean comparable to a skim, but in life expectancy / safety & quality etc

I guess what I really mean is would you fit the $200us kit?

Edited July 6, 2016 by Haz77

[Eagle 1662]

Everytime ive needed rotors ive ending up buying NZAD ones. Had them on at least 4 BMW's, have all been driven hard on the road and track with OEM pads and race pads. They never had any issues and are priced well.

[Haz77 0]

Just ordered a pair of Zimmerman rotors & "road house" pads (apparently premium euro) $400 delivered from NZAD, not had time to check out mine so will see what they are like when they come off.

Where is a good place to get new sensors, I have an ebay account.

[Haz77 0]

Just had the wheel alignment etc done, report says

"Lower front caster arm bushes getting worm & have movement, replace within next 12months"

Guess I may as well get them changed while the rotors are being done.

[BlackAngel 60]

Just did all four rotors and pads in my e39 520i for about $350 from Extreme Autoparts.

Had a brake shudder that I've been living with for awhile now. VTNZ never noticed it coz they test on rolling road but dealership failed it on a warrant  after road test along with front tension arm bushes and rear brake hoses.

Replaced front tension arms - shudder reduced but still there.

Replaced rear rotors and pads (since steering didnt seem affected much) - shudder still there

Replaced front rotors and pads - smooth as silk now. 

I dont think there was anything wrong with the front rotors apart from maybe some disk thickness variation of pad deposits. Certainly nothing you could see with the naked eye - verniers didnt really show any variation either but . . . . . . You can muck about with skimming/sanding etc but the hotspots created by DTV can change the metallurgy of the discs locally and the problem can re-appear a little down the track.

Anyway, by the time I had replaced both front arms, both rear brake hoses, all rotors and pads, bought 2 cans of BMW brake fluid for bleeding and a wedge/fork type ball-joint separator tool (which doesnt work on the e39 btw due to contacting the hub before separating the joint, ended up using the double hammer method) - I had spent just short of $800 in parts - all labour was my own.

Pretty happy considering BMW quote was $2800 to do it all - but that also included rebuilding all the calipers.

Sidenote: After doing all that the service manager asked me if anyone was looking for an '02  530i e39. Has done 238,000km, blue with motorsport bodykit and wheels. He is 2nd owner and has had it last 15 years so probably serviced up to the eyeballs with genuine parts. He's looking for around 2.5k for it. Bought his wife an X1 and he gets a company car so not being used . . . . message me if you want his contact details.

Edited November 4, 2016 by BlackAngel