So... my wife has a 2010 Mazda 3 i Touring sedan (with the 2.0L/auto combo) and I just did brakes on it about a month ago. In the morning, especially when it's damp, when she is backing the car out of the driveway, it makes an ungodly howling sound, kinda like a dying elephant or something. I can't figure out why.
When I replaced the pads and rotors, I anti-seized the inside of each rotor on the hub mating surface, the caliper slides, and pretty much everything else that moves. The emergency brake works fine, so it's not sticking. When I did them, I bedded them in properly after, and they stop well and feel great. I used Wagner ThermoQuiet OE-compound pads and new Centric blank rotors. Ive used these on other cars with no issues. The only thing I didn't do is spray the back of the pads with anti-squeal. They have a anti-squeal coating on them right out of the box.
Anyone ever have a problem like this? And no, it's not me. 
I've done many brake jobs in my time, and this has never happened to any of my cars.
it's typical. i've always just lived with it.
usually something i notice with semi-met's though. not so much the ceramics.
Make sure the tab on the rear pads backing plate is seated into the recessed notch on the caliper piston. I helped a buddy with his Accord that was doing the same thing on the first couple stops -- self adjuster mechanism for the rear e-brake didn't like having a 1/8" square pad contact surface.
Tyler H wrote:
Make sure the tab on the rear pads backing plate is seated into the recessed notch on the caliper piston. I helped a buddy with his Accord that was doing the same thing on the first couple stops -- self adjuster mechanism for the rear e-brake didn't like having a 1/8" square pad contact surface.
It does sound like it's coming from the rear, so I'll check this out. Thanks!
My 2007 Mazda3 with stock brakes makes this same horrific sound on only while backing out on damp mornings with light to moderate pedal pressure. I normally jam on the brakes a couple of times to avoid waking the neighbors. I've always assumed that it was just a thin layer or mositure or rust built up on the rear rotors since most mornings it makes no noise at all.
Same issue on our Mazda5 after I wash it and let it sit in the garage. It's apparently loud outside the car too. I haven't had the issue since changing out the rear pads.
killeen_john wrote:
My 2007 Mazda3 with stock brakes makes this same horrific sound on only while backing out on damp mornings with light to moderate pedal pressure. I normally jam on the brakes a couple of times to avoid waking the neighbors. I've always assumed that it was just a thin layer or mositure or rust built up on the rear rotors since most mornings it makes no noise at all.
^^This^^
We have a 2011 2.5 sport hatch, and the same thing happens for us. If it's damp out, washed the car, etc. and the car sits overnight is sounds awful backing out of the driveway. Then it goes away and is silent...... Who knows???????????
I dunno... my 2012 2.5 hatch doesn't do this. I have just about 42k on it so far and it's never done it once. Weird. 
Yeah, I don't really understand it either? I have looked it over and haven't seen anything out of place. Plus, you can't have service look at it because is gone once you get there. Doesn't happen enough to really bother me.
Do the rear pads have a chamfer around the edge? If not you can pull them and add one. If you want to cheat just scuff the edges against the pavement. Install them with some anti squeak stuff on the back and see if that works. I’ve had this work a few times to quiet down brakes.
On my GF’s Mazda 3 I tried a ceramic front pads from Advance and all they did was make noise when stopping at low speeds. Went to a different compound 2 days later and the noise was gone.
Surface rust. Common on any disc brake .
If it goes away after a couple stops or less, forgetaboutit.
