What causes squeeking for Brakes??

[GaryFenza]

I have a 2001 Pontiac grand prix se, just put new ceramic brakes on the car, rotarts have slight lining/rings/ridges, verrrrry small. It squeeks alot, i didnt put any of that grease on their, whats causing my squaking?? and what should i do specifically?

[vamc]

When it gets hot, the serface tention changes. roter expands. you might need new roters.

[richtazz]

Never put ceramic (or any other composition) pads on an old rotor without resurfacing it. The grooves in the old rotor surface do not allow the pads to seat properly, and not only will it cause a squeal, but it will reduce braking force. You need to either have the old rotors turned, or replace them with new. You will also need to sand/grind the pad surface back flat before reassembly. The grease you refer to is only for the caliper bolts and where the metal part of the pads slide in the bracket. Never apply it to the braking surface of the pads or rotors.

[GaryFenza]

gotcha^thanks