Squealing Brakes

[Enigma]

About a year ago I changed the front pads and rotors on my trusty commuter, the Echo.
And just recently the brakes have started squealing quite bad. It's most annoying, kind of embarrasing, but it still stops fine.
I pulled a wheel off and inspected; pads still have lots of meat. Rotors look fine, no apparent scores or glazing.

So what can be done to get rid of this noise?

The irony of the situation is I bought the pads/rotor's at my local auto shop where I get a pretty good discount ,without even checking at Toyota, thinking they would be way to expensive. I find out later that Toyota was cheaper.

 

[Gumby]

Rinse them off. Water works. Brake Kleen works too.

Could just be dust build up. happens a lot with newer pads as they break in.

 

[bandy rooster]

what material were they made out of?

different kind of brakes create more dust then others... organic, semi metallic, ceramic....

 

[Klunky Chris]

still have the anti squeal shims installed? tried anti squeal grease?

 

[grant5127]

Some pads are noisy than others. Semimetallic pads are typically the ones that cause the most noise problems because they are harder than nonasbestos organic (NAO) pads. Their high metallic content often makes them squeal when metal rubs against metal.

The amount and type of fillers and binders in a friction material can make a big difference in the amount of noise a given set of pads or shoes produce. Ingredients such as graphite, carbon and "rubber modifieds" may be added to reduce noise. Brass is another ingredient that helps dampen noise (it also has a cleaning effect on drums and rotors). Many of the newest pads designed for quiet operation use a nonmetallic "ceramic-enhanced" formula to eliminate noise.

The design of the pads themselves can also affect the amount of noise produced. A chamfered leading edge on the pads eliminates the sharp edge so the pads will slide across the rotor without grabbing and vibrating. Slotting the pads changes the frequency at which the pads oscillate so noise can be tuned out of the brake system.

Some pads also have a special coating that transfers to the rotor surface when the pads are first used. The coating material leaves a film on the rotor that reduces noise, vibration and also rotor wear. The transfer film also makes the pads less sensitive to variations in the surface finish on the rotors.

If the replacement pads are too noisy and can't be quieted by insulator shims, noise compound or grease, therefore, replacing them may be the only way to get rid of the noise.

 

[tlcruiser66]

The shims on some pads can loosen from their rivets and cause a lot of squeeling, check them. If ther are loose, i'd just remove them and be done with it.