Unusual Rotor Wear - Noisey Brake Squeel.

[dori34]

so i just changed to new RDA extreme pads for a street/daily car.

they've had around 1000km on them and the rotors were machined as well, they are now showing weird wear marks on them, which i've never seen before. i think this may be the case why my brakes are squeeling so bad, it is very annoying, im going to try CRC stop brake squeel this weekend, rub the pads on some concrete and machine the rotors again and fingers crossed it gets rid of the squeel.

in some areas, it is more shiney, is this an indication that they are glazed? If so, would glazed brakes contribute to squeeling and why would it get glazed so quickly.

this is going off SargeRX8's thread in which he tried everything to get rid of the squeel but it still existed.

It doesn't happen when in reverse or when braking up hill.

Its quite embarassing driving my car when brakes are squeeling this loud.

can anyone shed some light on this?

Cheers

[34GeeTeeTee]

What did the face look like when you fitted them man? It looks like its been machined with a blunt tip the way its worn?

Were your pistons and slides all free when you fit them up? Not sticking and holding the pad on the rotor slightly causing the glazing?

[dori34]

it was smooth and flat when it was machined as i felt them before it was fitted.

my mechanic installed the brakes so i would assume there wasn't any issues as he didnt mention anything.

gonna have to take it apart this weekend and get the rotors machined again.

[GTSBoy]

Don't machine the rotors, that's just a waste of metal. Take enough caliper/dust shield off the discs so you can access both sides with some emery paper and give them a rub all over. You're looking to clear up the sticky crap that has been deposited onto them from the pads. No need to worry about removing metal and making the surface uneven. You'd have to scrub in one spot for ages to do that.

Then scuff the pads up like you said you were going to do. Put it back together and go and do a pad bed in procedure.

[simpletool]

does it see the track often? If not use copper grease on the backing pad and shim. Solved.

Also could be sticky pots in the caliper. Rebuild kits are cheap, it's easy if you have compressed air and some decent clamps (for the remaining 3 pots).

[KiwiRS4T]

Also slightly chamfer the leading edge of the pads.

[Reflector]

so i just changed to new RDA extreme pads for a street/daily car.

they've had around 1000km on them and the rotors were machined as well, they are now showing weird wear marks on them, which i've never seen before. i think this may be the case why my brakes are squeeling so bad, it is very annoying, im going to try CRC stop brake squeel this weekend, rub the pads on some concrete and machine the rotors again and fingers crossed it gets rid of the squeel.

in some areas, it is more shiney, is this an indication that they are glazed? If so, would glazed brakes contribute to squeeling and why would it get glazed so quickly.

this is going off SargeRX8's thread in which he tried everything to get rid of the squeel but it still existed.

It doesn't happen when in reverse or when braking up hill.

Its quite embarassing driving my car when brakes are squeeling this loud.

can anyone shed some light on this?

Cheers

I would double check your mechanics work. I myself am a 3rd year apprentice mechanic and I can tell you I've seen some pretty weird and scary things done by 'Qualified Mechanics'. Those wear marks look as though a surface as hard (or harder) than the rotor itself has been making contact on there. Check to see that the pads have been put in the right way around with the correct surfaces facing the rotor. As unbelievable as it sounds, some people install (I don't know how you possibly could) the pads around the wrong way. It does happen.

Also, do NOT rub your pads on concrete. By some fine grade sandpaper and rub the contact surface on the pad on there in a 'Figure of 8' motion until the surface of the pad has become lighter in colour and consistant across the whole face.

EDIT: Either that or your mechanic didn't bed the brakes in and (if) they had a titanium strip it's slowly been making contact. Though I wouldn't think it'd last too long.

Edited May 27, 2012 by Reflector

[dori34]

does it see the track often? If not use copper grease on the backing pad and shim. Solved.

Also could be sticky pots in the caliper. Rebuild kits are cheap, it's easy if you have compressed air and some decent clamps (for the remaining 3 pots).

does not see the track often, put some copper grease on the backing pad and shim and also anti squeel sealant from Dynagrip, lasted 10km before the noise came back.

i highly doubt it is a sticking pot in the caliper as it happened as soon as the old pads (i think they were EBC as they were yellow) were replaced with new QFM A1's, i have since changed them to RDA extreme and still the same.

Also slightly chamfer the leading edge of the pads.

This has been tried also, lasting only 10-20km before the noise came back.

I would double check your mechanics work. I myself am a 3rd year apprentice mechanic and I can tell you I've seen some pretty weird and scary things done by 'Qualified Mechanics'. Those wear marks look as though a surface as hard (or harder) than the rotor itself has been making contact on there. Check to see that the pads have been put in the right way around with the correct surfaces facing the rotor. As unbelievable as it sounds, some people install (I don't know how you possibly could) the pads around the wrong way. It does happen.

Also, do NOT rub your pads on concrete. By some fine grade sandpaper and rub the contact surface on the pad on there in a 'Figure of 8' motion until the surface of the pad has become lighter in colour and consistant across the whole face.

EDIT: Either that or your mechanic didn't bed the brakes in and (if) they had a titanium strip it's slowly been making contact. Though I wouldn't think it'd last too long.

pads are installed correctly and hey won't go in any other way.

the RDA extreme pads im using are semi-metallic, could it be the metallic > rotor contact that's causing it? maybe i should go to some ceramic pads for street and see if it helps.

the rotors do look abit glazed and the pads were glazed as well before i rubbed them back. the wear and shine of the rotors is different to other skylines i've seen.

[75coupe]

noise in brakes is from vibration, could those marks on the rotors be from the vibration?

def looks like it...

Im about to install some Project Mu brake shims to rid my brake squeal, using rda slotted rotors and QFM A1RM pads.

Ive tried the anti squeal pastes that you put on the back of the pads, Ive even tried antisqueal spray which I wouldnt usually want to even use.

Ive rebedded the pads after giving them a scrub on flat concrete and Ive lightly sanded the rotors to get rid of glazing just in case.

Ive also used brake cleaner and thoroughly clean the calipers, pins, rotors and pads,

so the shims are all I have left to try, I havnt tried the copper grease I must admit but I though the back of shim paste stuff would of been similar tbh...

[dori34]

Let me know how you go Scott!

the PMU shums bing under $80 or so from GSL rally sport may be worth awhile investment if it gets rid of this awful noise.

did you have the same wear marks as me, or just brake noise only?

What pads were you using before and did you have any noises?

[75coupe]

Well thats the annoying part, i am using the same pads i had on with my previous rotors, same brand/model as well, finished off the old rotors at a track day, replaced the rotors, pads still had lots of life left and now i have brake squeal, i scrub the pads flat and fresh before installing on new rotors and all.

So yeah hopefully the shims do the trick, i had no brake noise on this same combo previously...

[75coupe]

Not the look to my rotors as yours though

[dori34]

it may be your retainer pins are worn or loose, can you push them in/out when it is fitted? I can move mine in and out a bit, maybe this is the issue for me.

i've been quoted for this full kit from the Uk for around 60 pounds delivered.

(minus caliper of course)