If the brake pads come with shims or other anti-rattle hardware and it is not used on the vehicle, the brake pads will vibrate against the rotor as they are being applied and that will cause them to squeal.
Frozen brake caliper
form_title=Rotors Replaced form_header=Improve your brake performance with replacement rotors. We will help find you an expert auto technician to install new rotors. What is the year, make and model of your vehicle?=_ Have you noticed any unusual shaking lately when you press on the brakes?= () Yes () No () Not Sure How long has it been since you had your brakes replaced?=_ Have your brakes been squealing or making any noises? = () Yes () No () Not Sure
It must be the rear brakes at fault.
Your brake rotors are warped and need replaced/resurfaced.
They need replaced when they wear out.
Could be that the rotors are "out of round" and need either to be resurfaced or replaced
Rotors may be out of "round" (lateral runout) and need to be resurfaced or replaced
Rotors out of round and need to be replaced or resurfaced?
Warped rotors. They need to be removed, turned or replaced.
New brakes do not grind. If you replaced the brake pads and resurfaced the rotors you may hear a bit of a sound but it is normal until the pads and rotors wear during normal driving.
Your rotors are warped. You need new brake pads and the rotors turned at a machine shop or replaced.
Rotors out of round - need to be re-surfaced or replaced