brakes squeal with new ceramic pads!!???

i just helped a friend install a set of semi metallic pads on his jeep and the thing squeals like a piggy everytime he touches the brakes. brand new pads. so we take them back and pick up some ceramic ones that are supposed to be silent. well they squeal just as loud every time he touches the brakes. do the rotors need to be turned even if they arent warped? they dont appear to be grooved very badly either. and YES we used the brake pad lube liberally on the backs of the pads. whats left to try?

I installed some of these ceramic pads on my 99 XJ about 1-2 years back.(hmm time to check them I guess...)
When I first installed them I had the same problem. I ended up taking everything apart again, cleaning the disks good to remove any grease or oil that might be on them, lightly sanding the surface of the disk and slightly sanding the surface of the brake pads.

Damn things still squeaked.

It got to the point of being embarrasing and I was thinking of replacing them. After a while though they just stopped squeaking. And when I mean "a while" I mean about a month.

MAP

olivedrabcj7 said:

do the rotors need to be turned even if they arent warped?

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Rotors should always be machined to provide a fresh surface to break in the pads. If you don't want noise - Do a complete brake job with good parts, not just hanging pads.

My rotors were new Raybestos rotors. I didn't think they needed machining. Since I was putting in new rotors I decided to get a set of ceramic pads.
The things still squeaked as I previosly explained.
My other discs were warped.

I have never machined rotors when I changed brake pads unless there was some rotor damage. And I haven't had squeaks or other issues from this either. It seems to me, machining rotors that are not damaged, just shortens their life.
In my experience, I haven't found it necessary to machine them just to change the pads.

I've found that Ceramic pads are a lot noisier than the cheapo pads, so I'm not suprised.

you should always have the rotor turned.you might not see it but the surface becomes uneven.when you install new pads the full surface of the pad will not make full contact with the rotor thus you will not stop as fast .it doesn't shorten the life of the rotor any.you find the lowest part of the rotor and cut till it all comes down to the ammount. you can usually cut a rotor about 2 to 3 times before it is to skinny to be cut anymore.hell whats the price of a new rotor .for the price you can get a rotor at i would replace the rotor every two sets of pads anyway

You "should" always have the roters resurfaced...However I have put allot of brakes on without doing it. You always run the risk of glazing the pads though. This will cause them to squeal.

I always use Wagner brand brake pads and shoes on all of my vehicles (89 XJ, 89 BroncoII, and 86 BMW 325(sometimes I like to go really fast around corners!!!)) and they never squeak.

ceramic brakes will typically squeal a bit until they get bedded into the rotors.

when I put new pads and rotors on my jeep, they didnt squeal, they sparked!!! I did a lap around block and when I did a hard stop in front of my house, my g/f said it was like a big sparkler inside drivers front rim.. Took everything apart couldnt find anything wrong, probably just some metal grinding of whatever getting rubbed off. Standard rotors and pads.

I too purchased some ceramics but they would only squeal when i was applying the brakes while going in reverse but shut up after about a week.

If the rotors aren't gouged and there was not previously any "thumping" or vibration when you brake, I agree with U --F turning the rotors! I've never had to, but I DID have a persistent problem with squealing on my '98XJ when I changed my pads. The fix was easy. Maybe it'll help U. The squeal usually comes from METAL-to-METAL contact, not from the pad/rotor contact. Look at the square "notches" on the ends of the brake pad backing plates that ride on the calipers (the metal to metal contact where the pads must glide back & forth). On my calipers there was some obvious wear (a slight groove worn in over time) due to this metal-to-metal contact. If the wear is "deep", you can smooth it with some emery cloth first. Then you will need to spend a few bucks on a small can (not just the little packets) of high temp brake grease (usually blue-colored) and liberally grease these notches, in addition to the backs of both backing plates (where they contact the caliper). That killed the noise 4 good. Good luck.