I purchased a 2007 Mazda 3 in January. It has 3400 miles on it now and the brakes squeak like hell when the weather is cold or wet. Is there any info on why they do this? I took my car to the dealership for it's first check up and they said it was normal because they have grooved brakes. Is this true or are they feeding me aline?

 

Grooved brakes??? Never heard of such a thing, drilled andf slotted yes but your oem rotors are neither of these im sure. My Speed3 had some nasty squealing gonig on. Only in cold temps, the colder it was the longer it lasted. Mazda told me it was the fact that the brake materials on the Speed are much harder, paired with the possibility for a film or a layer of 'rust' to form on the rotor when sitting, that in the first minutes of brake time and cool temps squealing was normal and unavoidable. If it goes away with use or rising outdoor temps, don't worry with it. If it's all the time no matter what i say check it out.

 

the squeak is caused by the ceramic brakes that the mazda 3 uses. They are better for performance but will get debris such as brake dust and a layer of rust built up on them quickly. This is normal and is nothing to worry about, unless the squeak does not go away after a few minutes and driving and braking

 

You can purchasea productcalled "Squeal Medic" from an auto parts store (Gunk brand).

I've used this product in the past (not on my M3 - on another car), it helped. If the squeal is highly annoying, could be worth a try. The product does not affect braking performance. You do not have to dissassemble your brakes, just spray it on the rotor, which you should be able to easily see through the rims.On my M3, the rotors are clearly visible. If it doesn't work, you've only wasted the cost of the can.

 

Been cold again for the least two days, like down 34low-45high and mine squeaked a bit. Effin weather, but yea it'll go away.