Hi lubicksby4. Welcome to the forum. Why were the pads and rotors replaced so many times? Was it for the noise or were they worn out? There are a lot of little things experienced brake mechanics do during a routine brake job to prevent noises and there are a few things inexperienced people might do to cause noises. A common cause of a crunching noise is failure to place a light coating of high-temperature brake grease on the hub where the rotor mounts to. Failure to do so won't cause any damage or harm but it can cause a scary noise but mostly when cornering.
Rubber bushings in the suspension system can become dried and cause noises when the car goes up and down over bumpy roads and when the front of the car goes down during braking. Warped rotors will make the calipers slide sideways twice per tire revolution on their mounting brackets. If those mounts aren't cleaned and lubricated, any noise will be much louder.
Many of these noises can be found using a tool called a "Chassis Ear". It consists of six microphones that are placed at suspect points, then the car is driven while listening with headphones and switching between the microphones. Many mechanics have never heard of this tool but it has been used at dealerships at least since the mid 1990s.
Any other clues you can observe will help in the diagnosis of the noise. Do you ever hear it when not braking? If so, what conditions make it occur? Do you feel anything unusual in the steering wheel or brake pedal? Does the noise always occur at the same time or must the brakes be warmed up first from performing a few stops?
Tuesday, June 22nd, 2010 AT 2:39 PM