BML540

Bitium is correct. the only thing that cause disks to warp is heat build up caused by use.

I owned a 1995 BMW 325i that I had to have the factory disks replaced twice because they warped on me after only 5,000 miles each, under warrantee.

Then on my 1999 BMW 540i 6 speed I had one set of factory disks warp and one set of drilled rotors warp. BMW's are very prone to warping.

My mechanic friend told me it was due to the thickness of the disks and the heat build up, even though all BMW have cooling vents that direct cold air into the wheel well.

NightRider

Why did you make you SN BML540 instead of BMW540? DId you think you would be shunned away? :P

dsc888

Brembos are superior in my opinion. My 97 Camry went through 3 sets of front OEM rotors. I replaced them at or nearing every 30K. I finally went with Brembo OEMs and they were perfect. They were made in Italy and I think that Bembo should be the OEM supplier to more cars due to their ability to make them so much less warp prone.

dsc888

Bitium

I know this guy that has what has been so far very good rotors. I bought a pair of slotted/crossdrilled, they were doing fine, but then one of the pistons on my right side caliper was getting stuck (not rotor quality related) anyway it damage my rotor.

I decided to buy another set, but this time for the first time I just bought slotted, I think they are better and have less fade. No warping and trust me living in germany does make me drive like a maniac.

He will give me a special price, if you are interested, just PM me.

BTW, this are my 5th set of rotors including stock, but not including resurfacing in between.

abqhudson

Took my 4 1/2 month old car (12810 miles) in today for an oil change and asked that they check out the steering wheel shudder experienced under moderate braking from 65-70 mph.

They replaced the front rotors and installed new pads.

Jim

skd2k1

iTrader: (1)

I'm not sure about the bmw's being prone to warping...I had a 95 m3 with braided lines and cross drilled rotors and they never warped and I drove the hell outta that car...in fact your eyes would pop out if you slammed the brakes in that thing. My rotors on my tl have been warped since I bought it but I'm assuming it was a result of the driving habits of the previous owner. I'm about to buy some new rotors...any suggestions on some good slotted?

geekybiker

This is the cause of "warped" rotors the vast majority of the time. Pad build up. However cutting the rotor should give you a clean surface. In any case if you do go 5-10 HARD stops from 70-20 or so (you dont want to come to a complete stop) And then either drive around without stopping for 10-15 minutes to cool the brakes or stop somewhere where you can use the ebrake to stop and stand. The idea is you want to scrape off the old pad material and get the pads hot enough to redistribute a smooth layer of pad material on the rotor. Then allow it to cool without having the brake pad pressed against the face (This will leave an impression)

gauravp123

I find this hilarious and providing no assistance to this thread whatsoever but...

^^^^^^^^^^^^^I'm with above stupid LOL

KJSmitty

Have you ever seen a rotor on a lathe - or actually perform a rotor turn yourself? I'm not stating this as a focused comment towards you geekybiker, just anyone interested.
Seriously, I wont claim definitively that the above won't or couldn't happen, but I have turned probably 500+ pairs of rotors in my lifetime and not one was anything other than,,,,, you guessed it "warped..." Not a one had anything to do with brake pad material build up on the rotor. Just plain old "out of true" metal-rotor surface.

Next time you're in the shop and see a brake lathe. Run over and look in the waste tray. There's a reason it's full of "metal" shavings vs break pad material.

If you do perform the above procedure - be prepared to have even worse warpage after your 1-5 hard brake applications. Once warped, they only get worse.


Cheers

JCL622

yes, over tightening the lugs can warp your rotors faster, however, honestly I'm going to attribute this to just the way you drive. I go through the same thing. Actually, I don't really drive recklessly, I just drive a bit more aggresively, coupled with the horrible weather and the horrible drivers around where I drive, heavy braking is expected. You're from chi-town, i'm gonna assume the same.

honestly, just invest in some better quality rotors, and prepare to have em changed periodically. I have 19k miles on my 4 year TL and I've changed the rotors twice and have gotten 2 new sets of tires and changed the front twice. yea, it's pricey, but i enjoy driving the TL, and if i'm not a danger on the road to others, to each his own


btw, if it makes you feel any better, according to the trip computer, my MPG is 12/15......and i usually only drive local.....lol -> shrugzzzzzz (i just scrimp on food and play my stocks correctly to compensate )


but yea, just get new rotors, it's not worth brow breaking over this, the stock rotors are good, but not great, and if you're in stop and go traffic like in Chicago, it's even worse. I have to honestly say, Chicago traffic made no sense to me, it actually made me angry, NY drivers are jsut dicks and we like it that way, Chicago...just didnt make sense.

Bearcat94

So .... uhmm, ..... you didn't notice this comment was 3 1/2 years old?


I find that hilarious and providing no assistance to this thread.

JCL622

lol god damn need to delete this thread to save humiliation lol

geekybiker

Not saying rotors dont get warped, but alot of complaints of "warped rotors" are probably pad deposits. The method I outlined above just takes a few minutes to try and can often clear up vibration when braking. If it doesnt work you haven't lost anything and can proceed to cutting (which is just a short term fix if they're really warped) or replacement.

gauravp123

nope

Tech7427

lmao to this thread.. hahaha..

well anyway, ive done multiple new cars with 1000 or less miles on them because of warped rotors caused by the car sitting on the lot for months at a time before they get sold and never drive resulting in buildup or rust and the pad tends to stick to the rotor.. the rust causes uneven wearing and higher braking temperatures, thus resulting in out of true, excessive runout, whatever youd like to call it.

we at acura use on the car brake lathes.. this way the rotor gets cut true to the hub surface..

i really like the, couple hard stops from high speed to "scape" the pad material off..
it would actually result in high speed glazing of the rotor/pad and thus again not true rotor.

i cant believe they keep turning them. at some dealerships.. i always try to get a new set and throw on there along with new pads.

i cannot stand when a customer wants to keep the same pads after a simple rotor turn..ughh. then they come back with rotors warped a few thousand miles later.

cheers

mmade22

Spoken like a true tech. If you cut or replace the rotors, replace the pads!

KJSmitty

All depends,
I turned mine at ~14K, TL now has 36K and they have yet to warp again. I also left the OEM pads. Typical rotor "warpage" many times has nothing to do with the break pads. If you have a nice thick piece of flat glass and sandpaper to check the pads, they can be re-used. However, not something I would recommend to Joe-Blow unless he was a competent/knowledgeable tech etc..

Nothing wrong with turning rotors unless the warp and subsequent cut results in less than desired/req thickness.

Cheers