Grinding front disc brakes

[ColoradoTxJeep]

I've got an 03 Wrangler X with 85,000 miles on it. This is the first time I've changed the pads. (Lots of highway miles and downshifting for braking). Anyway I replaced the the front pads (back shoes also, but their fine) with the recommended Performance Friction pads from Autozone. The front driver's side is fine, but the front pax side has a constant grinding sound. It is not a metal on metal squeaking sound, but a pad on disc type of grinding sound. It deceases in intensity upon braking, but doesn't entirely go away. My first thought was that the pad is not sufficiently off the disc during normal driving. So I removed the pads and cycled the caliper through several times to ensure free travel, and cleaned again. Additionally, there is a tight boot around the caliper to prevent grits and grime from getting in there. So I'm currently ruling out caliper travel issues. I lubed up the back of the pads (where the caliper contacts it) with sufficient lubrication. Though the rotor was not completely smooth, it didn't have significant grooves so I didn't turn or replace them. I've thoroughly cleaned the area with brake cleaner.

Based on my research of other braking issues within this forum....

My thought is the pads may grind until the pad makes a perfect match to the rotor. Will it be a problem waiting a while to see if this happens?

Another thought is rotor glazing. But why doesn't the driver's side have that problem? If it is glazing how can I determine that? And what is the solution? Can I scuff the rotor up with sandpaper or something?

Any other suggestions?

Thanks.

[Kiwi_TJ]

Whenever I have had pads replaced, the dealership has always skimmed the rotor as well. That way the new pads have a new rotor surface to mate with. They only take off a very small amount of the rotor.

Hope that helps

[j0nesy]

i only ever had a rotors turned on one vehicle, my old ZJ .... never on any other vehicle as new rotors were just slightly more expensive than the cost of turning ....

that being said, it is a good idea to have a rotor turned if it does not have a smooth friction surface .... or just be replaced. they can cause some slight braking issues until the pad wears to form to them (grinding, brake wobble, premature pad / rotor wear, etc)

is it bad to let the pad wear down until it forms to the rotor? ehhh .... depends on your definition of bad. its evil, but a lesser of two evils for some ....

[PeteC]

I have replaced pads without replacing or turning rotors on many occasions.

I am from the generation that had rotors turned several times since they were much thicker.

Yes, you may get a grinding when the rotor and pad do not match up. Yes, it may go away as the pad settles.

Now my question. If this is the first time you have replaced your brake pads in 85,000 miles (which by the way is pretty darn good pad life no matter how you drive it) why not swap out the rotors as well? They are not that much money. Swap them, start fresh and maybe you will get annother 85,000 miles from your brakes.

[TJeeper]

Did you grease the caliper bolts?

How do the sliders look? Did you keep them greased? On my ZJ the divots are so bad, when I put new pads on the calipers would get stuck on them and not release after braking. Makes a grinding sound.

[Jerky bump]

Check the metal shield isn't touching the rotor. Other than that, is it a steady noise or is there a frequency to it?