LANDONZ

iTrader: (23)

My car makes a chirping noise when I press the brakes?? just wondering what it could be..Ive changed the pads and rotors and it still makes the noise loud.. Could it be a vaccum or something?
Thanks

JasonWW

iTrader: (2)

Have a sound clip or something?

dailydriver

Do you still have stock pads on there?? If so, (and if they're worn down) that could be the low pad warning clip which makes a "chirping" sound.

LANDONZ

iTrader: (23)

yes, they are the factory pads..you think if i change them it will stop..i noticed now its starting to squeek some.. thanks for the help

JasonWW

iTrader: (2)

Are you saying you put new factory pads on the car?
The wear indicators should not be making contact if that is the case.

Did you lube the guide pins good?

RelentleZ

iTrader: (4)

Guide pins? I just bought my first camaro and the dealer turned the rotars and put new pads on and the darn things squeals like a dieing cat. Im thinking i have the same problem as above...

JasonWW

iTrader: (2)

The brakes are a floating caliper design. The pistons are on one side and push outward. They push the pad into the rotor on the inside. The pressure causes the caliper to be pulled inwards which pulls the outside pad into the rotor. It's not the best design, but it works OK. One of the things necessary for this design to work is for the caliper to be able to slide left and right smoothly without getting cocked sideways.

You have the PAB (pad abutment bracket) which is a heavy steel bracket that bolts to the spindle with about 74ft.lbs. of torque. The guide pins are long metal rods about 7/16" in diameter that slide into the PAB. The caliper then bolts onto the end of the guide pins with smaller bolts torqued to about 23lbs and loctited. The whole caliper can slide back and forth on the pins. If the pins are rusty or bent slightly the caliper will not slide and may cause one side of the pads to not release. This will wear out one of the pads quicker than the other as well as generate excess heat. It may also create noise.

The pads also have a metal spring clip on the top that keeps the pads under tension pressing downward. They can also get rid of noise.

If you are not afraid to work on your brakes you can remove the caliper bolts, slide the pins out and make sure they are properly lubed (there is special brake caliper lube available). Put it back together with loctite and torque the bolts to 23lbs or so. Or at the very least you can check to make sure the spring in the center of the caliper is there as well as the metal shims on each end of the pads.

One thing you might try is bedding in the pads. A lot of folks don't do that with factory pads, but it may help. Find a long strech of road, bring the pads up to temp with a few normal stops just to get some heat in them. Stop from about 50 down to 10 with 60-70% pedal pressure back to back about 5 times. If you feel the pads starting to fade then skip right to the next step which is to not use the brakes for maybe 10 minutes. Just cruise down the road and let the air bring them back to a normal temperature.

RelentleZ

iTrader: (4)

Wow i think that answered my question. Thanks bud. i guess i have something to do this weekend now.

JasonWW

iTrader: (2)

Another thing you can try is getting some Permatex disc brake quiet. It's in a blue can and sprays out a blue tacky substance.

You can lay your pads on some paper, material side down and spray some of it on the back of the pads. Let it get tacky and then put them back on the car. On most cars you don't see the pads through the rims so it's no big deal. We used to do that all the time on brake jobs, but the f-body usually has slotted rims which can expose the pads. It will make the exposed portions of the pad look blue. It's only a small cosmetic thing, so you may want to mask off the part of the outer pad that you can see. It's up to you though.

Noise is most commonly from the pads moving the tiniest bit under braking. It's a small ocillation that when at the right frequency makes an audible squeek. That's why the factory uses clips to keep them pressed into place which lowers the frequency. The tacky material basically does the same thing, help hold them in place. You don't really have to stop it from vibrating as it doesn't hurt anything. If you can just lower the frequency, then you won't hear it and that is all that matters.

Since I'm bored, tell me some more details. Does it squeek really loudly or faintly?
Does it sound like metal on metal grinding?
Does the amount of pedal pressure make a difference?

joecar

Where on the car does the noise come from...?

JasonWW

iTrader: (2)

Assuming that the guide pins are lubed, the sound almost always comes from the pad to caliper contact area.

I just thought of something else. The factory uses metal shims on the back of the pads. I tossed mine a while ago as they are known to get bent or bunch up under heavy use. If you want to continue to use them then there is a certain combo of lube and anti squeel used. Either you put the anti squeel in between the pad and shim and lube on the outside of the shim or vice versa. I can't remember which way it goes. Maybe someone here knows the way it's supposed to go. If you are really having trouble getting rid of the noise you might try removing the shim and putting the Permatex directly on the back of the pad like I mentioned above. Just save the shim in case you wn tto reuse it.
Also make sure they is a slight bit of lube on the anti chatter shims on each end of the pads. Make sure they are there first and then clean them up and then apply a light coat of grease where the pad makes contact on them. Here is a pic of them.


Also, here is a write up on doing a brake job.
http://www.installuniversity.com/ins...ds_mwarren.htm