Grinding noise with brake use

[yarista]

Hi Yaris peeps,

I am having a small issue with my 07 Yaris. It's a grinding noise that seems to start when I brake on a down hill that has a turn. It goes away and seems to happen mostly in the morning. But sometimes it happens later in the day. I replaced both front and rear brakes a short time ago. It had the noise before I replaced them. The brakes work fine and stop well. The car has 85,000 mi on it. I didn't notice any problems with the brakes when I replaced them other that a frozen front caliper slide which I freed and greased well. I replaced the front rotors but not the rear drums. The drums didn't have any score marks as the the shoes still had some lining left. So I am a bit out of answers. Any Ideas:confused: Thanks

[bronsin]

Frozen caliper slide? Im not sure what that means. A stuck piston on a caliper means you have to replace the caliper. It cant be "freed up". The problem will return.

Check the caliper again.

[Lux]

You can isolate which axle the noise is coming from by using the handbrake to actuate the rear brakes only and listen for the noise.

There is a steel dust shield bolted to each front steering knuckle that covers the brake rotor. It is flexible and easy to bend. Who ever service your brakes last may have accidentally bent it until it is scraping your brake rotor. Remove the wheel and simply bend it away to fix the noise.

You only hear the noise while loading and turning the front suspension because the wheel bearings have an engineered compliance: they flex under load instead of remaining rigidly straight. That compliant flex in the front wheel bearings allows the brake rotors to lean inwards and rub a distorted dust shield.

[jambo101]

Does it happen even when driving slowly? as the ABS system gives a grinding noise/sensation when activated..

[yarista]

Thanks LUX, that makes alot of sence, next time I take it to work, I'll try it.

[TOUGEghost]

Another thing you can do is make sure all the metal shims on the brake pads are on correctly and not rubbing on the rotor. It is possible to put some of them on backwards.