Diagnosing a brake noise, need help..
 

I have started noticing a sound when applying the brakes to my BRZ. At high speed, I do not note any noise. From 40 MPH, I start to hear a periodic squeak, almost squish kind of noise as I come to a stop. I notice that the sound repeats slower as I come to a stop, which tells me that the noise (rubbing, whatever it may be) varies with speed. I don't think my brakes are warped in any way but who knows. I am running stock calipers, pads on slotted rotors. Suspension was from last owner, from what I can tell they are Bilstein B8's with either OEM springs or eibach lowering springs. I also notice, from this awful road drop I have to drive over every day, that the suspension will give a hard squishy sound in the rear. But, this is after a cold start in the morning and immediately going over this bump. I know this is a lot of information, but please offer advice if you can. I need to know if it is a serious brake problem.

Have you, are are you able to take out the pads and take a look? Post pictures of your pads and rotors if you can so we can help. It may just be time for new pads.

We should be able to tell what springs are on there as well when you have your wheels off. Bushings and suspension parts can make noise on hard and fast impact movements and rebounds, and likely isn't anything to be too terribly concerned about...

I do not have pics at the moment, but maybe I can take a look pretty soon. Will try to get some pics.

Mine does the exact same thing. It started November of 2014 and my suspension and brakes were bone stock. I had 9k miles or so on the car then. When it started it disappeared shortly after, however it came back. I took my brakes apart to inspect everything, relubed everything, and noise was gone. It keeps coming back but shits up after lubing. I'm loosing my mind lol. I've replaced rotors thinking maybe they were warped, caliper slider pins (heard maybe one was catching) , and even caliper bolts themselves. It goes away and comes back. Now it's back with a vengeance. I repeat the noise only is audible coming to a stop while soft braking. Hard braking I hear nothing. I've tried rolling to a crawl in gear and in neutral. I'm thinking maybe replacing my caliper bracket/mount or replacing the pad hardware. My pads are still wearing evenly. Not sure WTF could be causing it. Any help would be appreciated.


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That's an accurate description of my situation as well. I don't know if it could be related to worn OEM bushings that don't secure the suspension as well as some stiffer ones. So you have OEM suspension right? Is anything aftermarket? (brakes, pads, rotors, struts, springs?)


I still haven't had time to jack the car up and look at the brakes. I'll hold off on this until I get more free time.

Everything is stock except suspension. When I first heard the noise I was bone stock. It shut up when I checked out the brakes and applied some more lube. It came back like 2 months later. Still have the noise even after I installed coilovers.


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Check your fender area for leafs just in case. I had almost the same problem thought it was brakes but I turned out to be leaves stuck in the fender.

Diagnosing a brake noise, need help..
 

Will check, but man if you heard the sound you'd know that it couldn't be a leaf lol. I found an old service receipt in my owners manual from the first owner who had apparently taken it in. It mentioned that the metal shims were rubbing and they lubed it up. Sooo I'm going to try different pads or remove the shims.


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Dude brake squeal is totally normal and will happen more often when cold. You have never tired race pads have you hahahaha!

I had squeal on my IS300, but this man sounded bad. I thought maybe a caliper was failing. It's only one corner too. Driver front brakes and I hadn't changed anything with them.


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I see this at work somewhat often, you most likely have warped rotors in the front, have them machined or replace them and either replace the pads or sand them down with a belt sander to a flat surface again, or else it will come back

Good looking out. I did buy a new rotor to see if that would correct it and it didn't. I just ordered some TRD pads though, so here's to hoping that new pads will fix the issue. My last resort is a new caliper too.


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Update?
 

How's everything working out for you on this? Mine are doing it at 20k. I just bought new pads. Hopfully that fixes it.

update? this is happening to me too. periodic squeaks.

I also had this problem. Subaru dealership said it was brake dust accumulation and blasted everything with cleaner. Sound is gone for now, but maybe it’s a temporary fix.

Perhaps there a mod we can do to blow the dust off the brakes continuously...

It's probably the slotted rotors being noisy- do you feel any vibration? How old is your brake fluid?

You could hook up a 100 psi compressor with all the lines and about 40 outlets that pulse individually to blow off each section of the calipers where dust builds up.
Or...
You can have your brakes serviced/service your own as per the recommendations in the service manual

The noise came back the next day. I think there is a different underlying issue.

So you have a squeal on slow speed stops coming from a specific corner of the vehicle, correct?

If it's barely a squeak and goes away after one stop, it's normal and I wouldn't worry about it. Any more than that on stock pads would be odd.

Warped rotors aren't really a thing. You can have uneven pad deposits on them, or uneven wear/runout, but warping is basically unheard of on modern rotors that have any thickness at all left.

First thing I'd do is jack up that corner of the car, turn the wheel and make sure the brakes aren't dragging at all. If they are, you probably have a caliper or slide pin issue.

Regardless of whether or not the brake is dragging, take off the wheel. Take the caliper off, look at the pads. If they feel smooth and look shiny on the friction surface, they're glazed over and need replacement. If they're glazed, replace the pads and make sure you lube the slide pins. Dry slide pins are one of the most common causes of glazed pads, pad noise, and/or uneven pad wear. Use grease, not anti-seize. Anti-seize is a great high-temp lube, but a terrible high pressure lube. It'll just squeeze out from between the surfaces it's supposed to be coating.

While you're at it, borrow a dail indicator and check your rotor for even wear. Anything more than about .005" variance is cause for replacement or resurfacing. You're going to have some variance, some from play in the wheel bearing and some just because things never wear perfectly, but it shouldn't be much. If your rotor measures out fine, and there are no grooves you can catch with your fingernail, you don't need to get them resurfaced. Going from stock to TRD pads or stock to new stock pads there won't be a need to remove the old pad deposits.

Also make sure nothing is stuck between the little dust shield and the rotor, and that the shield isn't bent into the rotor or anything like that.

Bed your new pads in properly. If you don't you can get vibrations and other issues from uneven material deposits.

You should be good at that point. If it happens again, and you made sure to lube the slide pins properly, I'd suspect a sticking caliper.