I have a 1997 Explorer, AWD. On Sunday, the right front side started making a really loud, high-pitched squeal, which stops when I step on the brake. I had my mechanic check it, and my brakes are in fine shape (replaced by the same mechanic less than a year ago), so why is this happening?

 

Usually, that indicates that the wear bar is contacting the rotor, but your mechanic ould have seen that right away.

Could be something as simple as a hard spot on the brake pad.

I've seen this happen on entry level pads most often.

Easiest fix is to replace the pads, but you might have some luck taking them apart and sanding the pads to get past the hard spot, but that usually ends up being a short term fix as it will likely happen again.

Any idea what kind of brakes he uses?

 

if it happens when your moving, and goes away when you apply the brake, then the PROBLEM IS THE BRAKE......... not much of a mechanic if he cant figure that out. Should be able to jack it up, roll the wheel/ tire and listen to exact location.. removing the wheel should be obvious what is squeeking ...... could be something as simple as the brake backing plate rubbing the disc, which moves SLIGHTLY when brakes are applied and then no squeak. Could be the brake pads themselves slightly touching the disc

 

It is the caliper slides, it is not returning to open position when released. When you jack it up you will notice that wheel isnt as freewheeling as it should which indicates the pads are still biting and causing it to squeel. Need to remove caliper and clean off the junk (usually old grease thats been baked on there throughout its life) and put new grease.