Ceramic Brake Grinding?

In September 2012, I had all of my brake pads and my front rotors replaced. On at least two occasions since then, I have noticed grinding. I took the car back to be looked at in October and today and in both instances the mechanics couldn’t find a thing wrong with the brakes. On Saturday, I was driving more than usual and they were grinding the majority of the time. I’m not sure why this problem comes and goes and whether it increases with use over the day. I find it easier to replicate when coming to a stop in the street rather than in the driveway at a low speed. Has anyone else experienced grinding inexplicably coming and going like this? Is there something I ought to have the mechanics test out? In each of these cases, they have test driven my car, but at the same time, I don’t want to tell them “Try driving it for an hour”.

I drive a 2007 Toyota RAV4 (about 56000 miles on it) and while I am aware of grinding due to slight rust build-up, that issue usually clears itself up after the first few brakes of the day (I believe that this is a common problem).

Do you know, or can find out, what brand of brake pads were installed back in Sept? I ask, because I’ve discovered that certain brands create conditions like this. It may be a mild brake chatter. Although they are not dangerous or very damaging, they are unsettled and undesired. I will never get brake pads again from Autozone after a similar brake feel like this on two separate cars I had years ago. Sticking to Raybestos, I’ve not had that problem since.

I’ve had the same thing from the AutoZone Duralast ceramic pads. I now prefer Wagner ThermoQuite.

I put new pads on my car and soon after grinding ensued. Replaced pads and checked rotors and no difference. Finally crawled under rear and closely inspected rear rotors and saw they were pitted on the inside surface. Very hard to see due to rotor dust shield. I changed rear rotors and quiet has returned.

@Stoveguyy the OP recently replaced all of the pads and the front rotors, as well.

If the front brakes are noisey because of pitted rotors, then those brakes must have been of inferior quality.

Most brake noises are caused because the two friction surfaces aren’t happy with each other, or the brake friction surfaces weren’t properly broken in.

When doing a brake job, you want to make sure the replacement components meet or exceed but not deviate from the OEM specifications. So if you use a ceramic friction material where a semi-metalic is spec’d, that can cause brake noise. Or if the proper friction materials are replaced, but the proper break-in proceedure wasn’t followed, this can cause brake noise.

Tester

She said rear rotors were not changed. I made an assumption rear rotors were ok since they were reused. I do not think she made any mention of turning rear rotors. Says rear pads were installed. MY rear rotors had pitting on inside surface. 2 different cars of course.