bones302

long story short, had a pair of EBC drilled and slotted rotors sitting in my garage for almost 2 years before I finally installed them this weekend. (waited b/c I also wanted to change pads and paint calipers).

anyway put everything back together and when I test drove, keeps making scraping noise that cuts in and out consistently. I tried bedding the brakes a bit, but not helping. doesn't feel like it, but to me it sounds like warped rotors.

will know when I get home today and pop off wheels. only thing I can think of is either brakes need to bed in more or the rotors are warped.

the rotors were in a box that was not stored on a perfectly level surface.

has anyone heard or seen of rotors warping from not being stored perfectly flat?

Brandon302

I wouldn't think they would warp from their own weight, does the wheel wobble when you brake?

dmichaels

Unless they had a manufacturing issue, they wouldn't physically change just sitting in a box. I'd suspect a couple things

1. manufacturing flaw - something is out of tolerance
2. When the rotors were installed on the hub, they were not perfectly flush
3. There are pad deposits on the rotor(s) that make it feel like warped rotors. This is very common, I've had the issue multiple times when switching from race pads to street pads on the same rotors.

Do you have any way of inspecting the rotor for surface profile? Could do a check to see if it's actually bent/warped or if the issue is something else

bones302

no wheel wobble. these rotors were treated with a cadmium-type substance or coating that keeps them black and the first couple of times around the block the brake pads had to rub off the coating as I braked.

the rotor profile looks good to me.

I only had time to drive it around the neighborhood a couple of times yesterday and was starting to freak out b/c I didn't want to overheat the brakes and rotors.

Now that I 'm confident rotors do not get warped from the way they are stored, I feel better and I'm suspecting the pads need to be bedded in more or I need to double check that the rotors are flush. I also think that the noise is coming from 1 side and I can easily double check that when I get home from work. I did notice one of the pads had a very small piece of material that broke off and didn't think it was a big deal. I'm willing to bet that made for an uneven pad surface.

dmichaels

Any part of the pads glazed? Depending how bad they are rubbing it could build up some significant heat. It takes a lot to overheat a set of brakes though, and the pad would be the first thing to go. The rotor should hold up to just about anything if you're just driving it on the street. I've cooked pads at the track before, but that's repeated braking from 120+ to 50. Just driving around with a bit of rub will make heat, but not sure it'd be enough to glaze part of the pad...

If the pad has some material broken off it shouldn't lead to the warped rotor feel, it should only result in slighly less braking power (less surface area). Doubt you'd notice it driving...

GBStang13

What you are experiencing might be a normal behavior with the first brake in period of the new slotted and drilled rotors. I doubt they warped, however what is happening since the pads are brand new and so are the rotors - you have to brake in them before they feel super smooth. Word of advice no hard sudden braking until at least 100-200 miles. Worked for me...

Bucko

Perhaps removing the rotors and taking them to a machine shop to have them checked for piece of mind will help. Rule them out for absolute cause.

Then you know it's not them if they check out.

dmichaels

To bed them properly you have to hard brake multiple times. The pads should come with bedding instructions. Usually it's something like 50-5 mph just below abs engagement 2 or 3 times then 60-5 mph another 5 or so times, then 15-20 min cool down drive with minimal braking. Much better then just driving normally for a couple hundred miles. Get the material transfer the right way and then brakes should perform bee well

Ronin38

^ This! Try bedding them better and see how it goes.

bones302

PROBLEM SOLVED.

feel a little dumb but was able to figure out sound was caming from one side and after I took the caliper and bracket off again, I figured out the splash shield was bent just enough to make contact with the rotor.

dmichaels

Glad it was an easy answer. I'd still highly recommend bedding in with some good hard stops (per the manufacturer recommendation). Makes an incredible difference.

bones302

yeah I did the bedding procedure yesterday before I finally figured out the problem. thanks for the recommendation.

dmichaels

Good deal!