KOALA97SE

iTrader: (17)

just installed new brembo zinc plated rotors with oem pads. first few miles were nice, but then i noticed a thumping sound. it turns out that there are a few small bumps on the rotors, one has more than the rest, and that one is making the noise. i think it could have come off of the pad or something. is there anything i can do about it, or would it go away in a few days?

2 Da Max

iTrader: (2)

i guess they have to break in, where did u get them from and how much?

amulla01

you could sharpen them out at mechanics probably

OneToughMax

yeah you have to get them turned. the raised spots on the rotors are deposits from the brake pads. when you brake hard, the pads and rotors heat up, and the pads will "burn" into the rotor, causing those bumps.

[edit]it's probably because you're running oem pads.[/edit]

salgue

imo, its always a good idea to turn new rotors (its only 5-8 bucks at a auto machine shop) and in general when changing pads.

KOALA97SE

iTrader: (17)

what does turning or sharpening mean? $5-8 for one rotor or for all four?

nyautostyle

salgue, u mean turning the rotors clockwise?

95BLKMAX

iTrader: (10)

They mean taking them to the machine shop to have them resurfaced. Those prices are individual per rotor. Around here in Miami, $10/rotor is the average.

KOALA97SE

iTrader: (17)

rotors have to be resurfaced when new? i did not change the front rotors and pads yet... should i have the new rotors resurfaced beforehand? i thought resurfacing was only for old rotors

njmodi

iTrader: (4)

Lots of bad information in the previous posts guys....

1. You don't want to resurface your brand new rotors. Why would you want to take off some thickness when you just bought "new" rotors - they are supposed to be true and flat and even and all that - and if you paid for brembos you should expect them to be ready to go out of the box - other than cleaning off the oil (that prevents them from rusting).

2. No rotors I have ever bought (Nissan or otherwise) have ever had "bumps" that cause thumping... so maybe you got a bad batch??? :

3. When re-using rotors (i.e. changing pads only), you should have your rotors resurfaced - so you have a nice even surface for your new pads and smooth even braking without vibrations/shimmys.

Flava_24/7

iTrader: (46)

OEM pads should have nothing to do with it.
Ive been using OEM pads ever since i installed my x drilled/slotted rotors with no issues.

[/QUOTE]salgue, u mean turning the rotors clockwise?[QUOTE]
Turning is a term for having the rotors resurfaced.

I have never heard of having to turn new rotors. You guys give awfull advice.
Sounds like to me, either the new rotors had deposits on them before the install or werent smooth to begin with.
When the rotors where installed, did you clean them real well with brake cleaner?

amulla01

I know its not normal to smooth out the new rotors (i was kind of amazed), but in this case he has to do it or bring them back and exchange the defected rotors...

salgue

i didnt say that you have to, i said that imo you SHOULD. its ok if you guys disagree. there is always the possibilty of the rotor not being perfectly flat een when its new. either due to slight damage in transit or due to slight manufacturing imperfections. turning is the same as cutting which is the same as resurfacing. even so, i still suggest turning new rotors. there are imperfections that you cant always see. "you guys give awful advice" is not true. different people do things differently. more problems can arise from not turning the rotor than can from turning it.

njmodi

iTrader: (4)

I guess my point is that when I purchase a brembo or "supposedly" better grade rotor, I expect it to be manufactured to a certain specification/tolerance. If a particular manufacturer is not able to do that, then I would buy it from another one. If indeed my "new" rotors were warped/uneven, I would just take them back and ask for replacements - as amulla01 suggests. As soon as you turn rotors, you compromise their strength and ability to withstand hot/cold cycling and they become prone to quicker warping.

I have replaced 4-5 sets of rotors in the past few years (across my various vehicles) and I have never had a problem with rotors not being within spec out of the box. However I try to buy the OEM part or from another reputable manufacturer - rather than opt for the cheapest alternative - with the hope that I am getting a better quality part.

KOALA97SE

iTrader: (17)

i think the bumps are pieces of the brake pads that fused onto the rotors. the rotors were smooth to start out with. how much thinner would resurfacing make them?

amulla01

i never had this problem but I always used dealer rotors and pads for the max, cause other brands would cause annoying squeeks

nick

iTrader: (10)

Be on the look out for Brembo look- alikes , Tirerack.com just have sent me set of blank Brembo front rotors for my brother's 97 Aurora. Rotors did not fit and were made in USA by Century company , no Brembo marks on them or anything like that. I have installed those with new pads and the car was not driveable - the front rotors were rubbing on caliper anchor bracket. I had to take them off and put the old ones back on.

Just venting here

Even the box they came it said made in USA.

I have blank Brembos on my Max , wife's Geo and Dad's Altima - all of those were made in ITALY.


Nick.

Flava_24/7

iTrader: (46)

You shouldnt have to turn new rotors, period.
Each time you turn the rotors it just shortening the life of them
You should turn them whenever getting new pads. And you should get new pads whenever installing new rotors.
Not turning a rotor before applying new pads will simply result in uneven brake wear.
If your recieving rotors that have imperfections in them, or are uneven/warped from the manufacturer you should change brands.

Sounds like since his rotors already have deposits embedded in them, he is going to need to either lightly sand them, or have them turned.

salgue

i am not saying that any brand is bad. every manufacturer SHOULD make perfectly flat rotors, but there is always the possibility of imperfections. as far as making the rotors weaker by turning, not really unless you have them cut down way too much. i find it highly unlikely that the rotors have deposits embedded in them. they are made of much harder material than the pads. i have not ever had problems with rotors out of the box either. for most peoples cars i wont do it since they dont want to pay the 20 bucks it'll cost but on my personal cars i always do. just something that makes me feel more comfortable, might not be everyones preference but certainly not a bad idea by any means.

Flava_24/7

iTrader: (46)

Who said it weakens them. I said it shortens their life. You can only turn rotors so much before they become too thin and unturnable.

salgue

thats what i understood from "As soon as you turn rotors, you compromise their strength and ability to withstand hot/cold cycling and they become prone to quicker warping." and yes the life is shortened, but not dramatically so.

njmodi

iTrader: (4)

That was me, not FLAVOR247... I think that the thinner the rotor, the quicker it will warp (that might not be true - its just my belief and makes logical sense to me)... and I would associate more likely to warp with weaker... that was my reasoning.

salgue

oops, sorry. didnt realize that.

goodhead

iTrader: (4)

sorry to jack your thread but can you clean new rotor oil off witll brake cleaner???

TaTaToothy

I just got the brembo's from the GD and some oem pads from a online dealer. I had the exact same problems. I did the rear set first about three weeks ago. Smooth as silk. Just did the fronts last week and during my test drive i heard a little noise coming from the front right side. By the time I got home it was now a steady grinding noise whenever the car was rolling. Hitting the gas and braking quiets it down. Took apart my pads and saw the lower half look like it was crumbled or really rough. The rotor now has little bits of what i guess is brake pad bits. Definitely not there before. The problem could be the rotor or the pads. But since I had the rotors in my room for a few weeks before i installed, I did inspect each one very carefully and they looked perfect. The oem dealer can't warranty wear and tear parts like these. I've been emailing but it seems that I will just have to buy another set of pads from somewhere else. I've driven it about 5 days or about 40 miles and the noise is not going away. I hope my pads get here in time so i won't have to get new rotors too! Have yours checked soon.

4GenMaxMan

The solution is easier than you think. I have brembo xdrilled/slotted zinc plated rotors and had the same problem when they were new. The bumps were just hard spots of zink coating which did not wear off during break in. You have to get through the zink coating before you get to the metal surface.

Just take sand paper and smooth out the bumps.

As far as turning the rotors when they are new:
1. It is probably better to make a light cut over the zinc rotors to take off the plating material before break in but it is not necessary.
2. Cutting new rotors will not compromise their strength unless you take off a lot of metal.
3. Always use new pads after cutting the rotors.
4. Make frequent light to moderate stops durring break in. Avoid hard braking for the first 50 or so stops so you dont glaze the rotors.

Good luck with the bumps.