Installed new rotors/ pads, now have a grinding noise, HELP!

[nickbischoff]

I just installed new Adam's slotted/ dimpled rotors as well as Hawk Performance Pads, then took it for a drive to bed in the new pads/ rotors followed these instructions and heard a grinding noise coming from the right rear of the car. It sounds like the pad is rubbing up on the rotor. So I took the caliper apart again reinstalled the pads, spun the rotor to make sure it wasn't rubbing on the pad but as soon as the brake is engaged again it comes back

Now my question to you guys is what are your thoughts? And if I just continue driving will I eventually wear down the pad just a bit so it doesn't rub anymore?

Here's a sound clip, kind of hard to hear the grinding but its the best I cloud do (make sure to turn volume all the way up):



Thanks Guys

[AudiTFSI3o3]

i can barely hear it on my mac but did you see any grinding off the caliper itself? if you readjusted everything in the rear my only guess is wheel clearance.

another guess is maybe you didn't compress the rear piston all the way? was it tight sitting on the rotor?

[nickbischoff]

I compressed the piston all the way while changing the pads, the sound literally sounds exactly like the pad just rubbing on the rotor, I have even tried readjusting but like I said earlier as soon as the brake is engaged again the sound is back..... completely lost on what to do

Checked to see if I saw any grinding of the caliper but didn't. I also just uploaded a better video where I adjusted the sound so maybe you can hear it better now

[NorcalPB]

My Adams rotors make a noise similar, but slotted rotors will make a noise that you will have to get used to.

[Otter11]

My Adams rotors make a noise similar, but slotted rotors will make a noise that you will have to get used to.

Uggh. that's not what i want to hear especially since i just bought Adam's slotted rotors 2 weeks ago. Still waiting for them to come and cant decide on pads (Hawks, EBC Red or Stoptech). The reviews on all the pads seem to be all over the place.

[nickbischoff]

Thats what I've read but it doesnt make sense that its only coming from the right rear. I'm going to try and throw on the old pads on today just to see if the sound will disappear.

[FraggyA4]

Did you bleed your brakes after you changed the pads and rotars?

[nickbischoff]

No I didn't since they brake fluid was flushed 2k ago. I took off the brake fluid cap while pushing the piston back then put it back on and pumped my brakes when I was finished with the brake job.

[Stewy]

I have slotted / drilled rotors and they are "silent". I'm not able to hear this grinding you speak of. So are the pads fully seated now? Can you visually see any grinding or wear marks on the rotors that would indicate metal on metal?

[nickbischoff]

ya the brakes should be fully seated now, and I looked at the rotor and it looks like the pads have been rubbing on the inside of the rotor

[Stewy]

Snap a quick photo if you can. I can't imagine that they did, but maybe the pads are incorrect or not installed properly in the calipers? it's pretty hard to screw up, but not being there, I can't physically see it.

[nickbischoff]

Here's a photo:

I also took the caliper apart yesterday to ensure I did everything correctly which is why Im so confused on why I'm having this weird noise.

[Stewy]

Hmmm....and did Adams have anything to say about it?

[nickbischoff]

Havn't contacted Adam, but I dont think it has anything to do with the rotor.

[Ur-Quattro]

Damn, that is too bad - I got some slotted/drilled front rotors from Adam's about 2 months ago, and they are awesome so far. I have no pad noise whatsoever....maybe the piston is getting stuck down the first time you brake after being done re-assembling?

[nickbischoff]

Thats a possibility, Ill take my brakes apart again and try and lubricate the piston to see if that works

[shiro1745]

Here's a photo:

I also took the caliper apart yesterday to ensure I did everything correctly which is why Im so confused on why I'm having this weird noise.

This happened to me as well, I had to resurface a set of front rotor that caused bad vibration cause of that and my new rotors now show the same wear. It must be something with the caliper sliders not sliding easy enough as somebody mentioned. Look on the inside face of the rotor, I bet it's the same thing but on the exterior edge. I took my calipers apart, cleaned everything really really good and greased everything back with proper brake caliper grease. I will see how everything evolves.

Oh, I forgot to mention first set that showed this wear was PowerSlot and now zimmerman, so it's nothing related to the rotor, it's how the pads sit on the rotor.

[doublezero30]

Is it only when you brake or is It consistent when you are driving? Make sure you didn't bend your backing plate. It could be rubbing on the rotor. Just bend it away from the rotor a little bit. Also make sure there's no rocks stuck between the backing plate and rotor. I am on my phone and I can't hear shit but road noise in that video though.

[NorcalPB]

Alright so what you guys are saying is that slotted rotors should not be making a noise? The only reason I figure this is because the pads should always be touching the rotors (don't think you want debris getting in between these two things), and this would ultimately cause air to be discharged through the slots creating a noise? Just a guess...but this is what the Audi dealership mechanic told me and we had a heart to heart over Audis so I would be hurt if he gave me the run around lol.

[nickbischoff]

Is it only when you brake or is It consistent when you are driving? Make sure you didn't bend your backing plate. It could be rubbing on the rotor. Just bend it away from the rotor a little bit. Also make sure there's no rocks stuck between the backing plate and rotor. I am on my phone and I can't hear shit but road noise in that video though.

Its consistent whenever the car is in motion, the backing plate is fine I checked that yesterday since I know they can be the victim of the noise. You probably can't hear it on your phone, you need a computer speaker, and the sound can only be heard at the very end of the video right when I drive by the camera.

[Skyler@Achtuning]

Alright so what you guys are saying is that slotted rotors should not be making a noise?

In my experience some slotted rotors make noise while others do not, it seems to have to do with the shape of the slots. I have not heard StopTech slotted rotors make noise after they are bedded in.

[nickbischoff]

So I just took apart my brake and it looks like the rotor came warped, would you guys just recommend throwing on both the old rear rotors?

[NorcalPB]

So I just took apart my brake and it looks like the rotor came warped, would you guys just recommend throwing on both the old rear rotors?

Ya sounds like your best bet. Or you could leave it on and drive it to Adam (He lives close to us, Livermore I think)

[Boushard]

Installed a set of EBC sport rotor(slotted rotor) on my Ralliart 06 a while back, after instal the rear set I have a machine gun sound coming of the rear axle.

I bedin the pad according to the Hawks site and everything goes silent after that!!

[fly300kts]

This happened to me as well, I had to resurface a set of front rotor that caused bad vibration cause of that and my new rotors now show the same wear. It must be something with the caliper sliders not sliding easy enough as somebody mentioned. Look on the inside face of the rotor, I bet it's the same thing but on the exterior edge. I took my calipers apart, cleaned everything really really good and greased everything back with proper brake caliper grease. I will see how everything evolves.

Oh, I forgot to mention first set that showed this wear was PowerSlot and now zimmerman, so it's nothing related to the rotor, it's how the pads sit on the rotor.

What bother on your picture is the disc color being blue. It's a sign of permanent contact between the disc and the pads. Since you are talking about the rear, what tool did you use to compress the piston.

Phil

[nickbischoff]

I went to autozone and rented a disc brake caliper tool set to turn the pistons in. I think the blue in the photo is just the reflection of something, in person the rotor doesn't actually look blue.

[shiro1745]

What bother on your picture is the disc color being blue. It's a sign of permanent contact between the disc and the pads. Since you are talking about the rear, what tool did you use to compress the piston.

Phil

Phil, I think you were talking about OP's picture, I jut quoted that, it's not my picture but I see the OP already answered. Anyway the rear brake piston has to be twisted when pushed in.

[nickbischoff]

So today I went ahead and replaced the rotor with my old one to make sure it wasnt the caliper/ pads/ piston being at fault. After the old rotor was on I took it on a drive and the sound disappeared from the right rear but now was also coming from the left rear (not as noticeable though). Also talked to adam and he said the rotor I received can't be warped since they are machine balanced before leaving the shop and that a good week should settle and prep the rotor/ pad.

I'm going to go ahead and throw on the other AR and drive my car for a week to see if the sound disappears, Ill post an update to let you guys know if it works. Thanks for everyones help

[nickbischoff]

Grinding noise is now gone after a week of driving, the only noise there is now is the typical sound you get from slotted rotors.

[CorneliusRox]

Grinding noise is now gone after a week of driving, the only noise there is now is the typical sound you get from slotted rotors.

good to know!

[mr shickadance]

Is it only when you brake or is It consistent when you are driving? Make sure you didn't bend your backing plate. It could be rubbing on the rotor. Just bend it away from the rotor a little bit. Also make sure there's no rocks stuck between the backing plate and rotor. I am on my phone and I can't hear shit but road noise in that video though.

i have done this, took off my wheel, wasn;t holding it right, the wheel barrell smacked that thing and i didn;t think much of it until i drove the car again