Squeaky Brakes

[chadmg7]

I recently had my local mechanic replace the front metallic brakes that he had put on with ceramic brakes. However, my brakes still squeak loudly sometimes (when I apply them), especially when it's rainy or moist outside. Why is this? I rarely hear other cars with squeaky brakes. Did they just do something wrong during installation?

BTW, I have "organic" brakes on the back I think. Are those crummy?

Thanks.

'97 ES300 -- 95,xxx miles

[SW03ES]

Some pads just plain squeal more than others. Typically the harder the pad the longer it will last, but the louder it will be. Nothing wrong with organic pads.

[ArmyofOne]

Some pads just plain squeal more than others. Typically the harder the pad the longer it will last, but the louder it will be. Nothing wrong with organic pads.

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ceramic pads are loud. thats pretty much all there is to it. they dont squeak, but i cna hear mine scrape the rotor. ceramic pads are very hard, leave very little dust, can stand extreme heat (NASCAR uses them on thier brakes) and will eat a regular rotor alive. i hope you have a high performance rotor. standard steel/iron ones will glaze over pretty fast (5 stops max) with ceramic pads on them...typically lexus uses a better quality rotor though, so i think you should be fine.

also, the are ventialted, so this helps.

[chadmg7]

Some pads just plain squeal more than others. Typically the harder the pad the longer it will last, but the louder it will be. Nothing wrong with organic pads.

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ceramic pads are loud. thats pretty much all there is to it. they dont squeak, but i cna hear mine scrape the rotor. ceramic pads are very hard, leave very little dust, can stand extreme heat (NASCAR uses them on thier brakes) and will eat a regular rotor alive. i hope you have a high performance rotor. standard steel/iron ones will glaze over pretty fast (5 stops max) with ceramic pads on them...typically lexus uses a better quality rotor though, so i think you should be fine.

also, the are ventialted, so this helps.

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What do you mean they will glaze over pretty fast? Does that mean that they will stop squeaking after 5 stops?

[ArmyofOne]

Some pads just plain squeal more than others. Typically the harder the pad the longer it will last, but the louder it will be. Nothing wrong with organic pads.

←

ceramic pads are loud. thats pretty much all there is to it. they dont squeak, but i cna hear mine scrape the rotor. ceramic pads are very hard, leave very little dust, can stand extreme heat (NASCAR uses them on thier brakes) and will eat a regular rotor alive. i hope you have a high performance rotor. standard steel/iron ones will glaze over pretty fast (5 stops max) with ceramic pads on them...typically lexus uses a better quality rotor though, so i think you should be fine.

also, the are ventialted, so this helps.

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What do you mean they will glaze over pretty fast? Does that mean that they will stop squeaking after 5 stops?

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no, no, no glaze is a bad thing. its when the rotor heats up anc then re cools and then heats up again so fast that the rotor goes smooth. like a mirror. when the rotors are exposed to extrreme heat, they "glaze" or lose their ability to let the pads grip them. the go so smoot that the pad just slides over the rotor, providing oalmost no stopping power.

glazing is not something you want, because it requires you to by new rotors. when they glaze over, 99% of the time they cracked. my front rotors cracked in 4 pieces when they guy took them off. pads are supposed to "bite" the rotor, for lack of a better term. when they heat up and then cool down and the heat up and then cool down and then heat up and the cool down, they lose their bite. thereofre, it feels like you are stopping on ice.

before i had my brakes done, it took me ~100 yards to come to a complete stop...with the pedal all the way to the floor...from 40 MPH, sqealing all the way.

when you change you r pads, you need to turn the rotor, this takes a thin layer of metal off, so the new pads have a fresh biting surface. did the brake tech do this? if not thats porbably your problem.

if you have under 500 miles on the new pads,then the problem is they arent broken in yet. you have to break them in just liek a new car. no fast stops for at least 500 miles. after the first 500, make a few fast stops from 50 or so MPH. this will allow th pad to "set" then you are set to go. squeak should be gone.

do this in reverse too. from about 20 MPH thopugh. it doesnt matter ifyour tires screech, if you do it righjt, they will.

[SKperformance]

Actually glazing is when brake pad material gets impregnated into the metal and creates a surface that is very bumpy and causes unequal braking and efficency of the pads to the rotors.

If you crack a rotor it is a very chaep or drilled rotor unless you race to get that kind of heat .

Glazing needs to be removed it doesn;t mean the rotors is dead either.

[ArmyofOne]

^not according to my mechanics^

In a disc brake, the brake pads squeeze the rotor instead of the wheel, and the force is transmitted hydraulically instead of through a cable. Friction between the pads and the disc slows the disc down.

if what you are saying is true, then that means that braking would be improved.

www.howstuffworks.com

http://auto.howstuffworks.com/disc-brake4.htm

i cant find a link at the moment, but basically, either your pads, or your rotorsd can become glazed.

glazing occurs under high heat. the surface hardens and goes SMOOTH.