Slotted rotors and awkward sound

[aaron1085]

So..I've asked plenty of braking questions, but this one is a bit different. I installed (5 months ago) slotted rotors and akebono ceramic pads on my stock 2007 A4 2.0t brake set up.

Ever since I did a track day, when I hit the brakes hard, I get like a grinding/drone sound from them. It almost sounds like the slotted rotors are cutting into the pads at a more pronounced rate; sounding annoying and feels disconcerning.

I'm not sure if anyone has come across this, but it's weird almost. Around town, the brakes feel normal, but under "semi-hard" braking, it just feels like the slots in the rotors are creating an awkward sound...

Suggestions? You think its the slots and swapping to drilled or solid rotors would cure that?

Thanks for replies and suggestions. Anything helps.

[mr shickadance]

slotted brakes hum.....i thought the exact same thing after i installed mine.....no worries 100% normal

[GA42.0T]

OK, so hum is OK for slotted rotors, but a click/clunk wouldn't be though, right?

I've got ECS slotted/drilled rotors and akebono ceramic pads. This is the SECOND set of akebono ceramic pads and both are clicking and clunking on me. The first set was so bad, they'd click everything I even tapped the brakes. On the second set now, and so far they only click once when direction changes. That is, back up in reverse, tap brakes, "click." Then move forward, tap brakes, "click." Thereafter, no click till I reverse again. Not as annoying as previous set, but I'm afraid they'll get worse.

Check this from another thread.

Pulled the Akebono pads and see what appears to be evidence that the pads are shifting in the calipers. Looks like they've been hammering against the calipers and that's what's causing the clicking or even clunking noise.

I don't know how OEM or other pads solve for this ** if they are shaped differently, have better clips or better coating, but it seems it's the pads that are causing the noise. As stated in the above post, I've not got second set of Akebono pads and the same is slowly happening with this set. The click isn't every time I break and isn't nearly as loud or noticible as it was by the time I removed the first set (pictured below), but the noise is definitly there some times and I fear the same will happen again. When it does, I'll have to go with a different pad.

Long story short, I won't use and don't recomend Akebono.


This pics show some marks at indicate pads are shifting. All four front pads have varying degrees of shiny, hammered spots like these. These obviously are the worst of the bunch.

[mr shickadance]

hmm idk too much about those pads, i only have experience with OEM and EBC greenstuff, sounds like the pads do not fit correctly

[GA42.0T]

yup. thinking the same thing. thanks.

[aaron1085]

hmm/....interesting. Anyone experience this with any other pads being used? Does anyone think the slots on the rotor may be the cause? I purchased them as OEM replacement from ECS.

[mr_esmit]

Could be the rattle clips also. Did you check to see if the pads were properly seated in the caliper??

[royal_b7a4]

i have the ecs drilled and slotted rotors with hawk pads...i do get this hum sound and its under semi hard braking but i only hear it as the car comes closer to a stop not the initial press of the pedal...i heard that its because to much air is building up in between the drills and slots so it causes a minor vibration? not sure if its correct but it sounds correct lol...i do not get any clicking sounds though

[aaron1085]

I see. No "clicking" sounds for me either, but this has become quite interesting to me now. I've never seen anything like this posted before and would love to hear some more input whether people experience this or not?

It is more prevelant as the car comes closer to stopping, but mostly under harder braking, almost makes me a bit un-nerved as it sounds like something isn't "right" ya know?!

[royal_b7a4]

It's more under hard braking as it comes to a stop....it hums lol

[matt94gt]

From experience with slotted rotors and Hawk pads, they do make more noise, it might sound like a slight 'grinding' noise but should not be anything loud, beside a median etc yes you might hear it slightly. OEM pads you should not notice it.

Slotted & Drilled rotors will sometimes make a "ticking" noise almost like cards in bicycle spokes (yes due to air apparently)...again, when beside a median it will be most noticeable, that is normal with slotted/drilled rotors depending on the build of them.

[ECS Tuning-Audi]

Some times our rotors need to be turned due to an imperfection in the machining of the slots. We found that simply turning the rotors solved this issue. If anyone is running our slotted rotors and experiences any sort of "clicking" under braking shoot me a PM we will cover up to $20 per rotor to have them turned.

Jason