I've searched on a couple different forums already for this information and I haven't found anything yet. I have a clicking noise coming from my passenger rear wheel that happens only while breaking and the frequency of which is proportional to the speed of my car. I took it to the dealership once already and they told me it was something in the break caliper but said it was fixable by grinding something. They did this and the noise went away for a week or so. The noise is back now and it worse then ever. The problem is that I went to the dealer when I was home on leave and I am now 800 miles away from the one I went to. I really want to get this noise fixed and have no time to look into it myself. I would like to have some sort of an idea what it may be when I go into the dealer down here so that I can tell them what to look for so they don't do something that is just going to get me off the lot so they can charge me for nothing.

 

Since it's only happening when you brake, I would suspect that the retainer springs on your brake caliper are broken or bent, and aren't holding your brake pads snugly. This would cause them to move a little between stops, and braking would cause them to shift.

If you unbolt the rear caliper (two bolts) and remove it from the rotor, you can tell if there is any play. The pads should be snug and not move around at all. If you can jiggle them around, you have a retainer clip that is either bent or broken. Each caliper has two retainer clips that hold the brake pad in place.

The shim behind the brake pad should be in place as well. If this is missing or shifted, this might cause a clicking sound. But if it was missing, you would have noisy squeaks/screeches.

 

Let me (us ) get this straight:
You drive and start to brake, then you hear a series of clicks until you are stopped?
Click.click..click......click................click ..................................click........... stop

IMO a broken or damaged pad retainer would produce one click at the start of braking (while the pads shifts) and not a series of clicks (a pad that keeps shifting while braking).
But I could be wrong....

How does the surface of the rotor look (the side you can see.. it has 2 )
Can you see the outer pad and guestimate the thickness?

You could call the dealer at home and ask what they did.

I'm

 

Been here, had the same sound and symptoms. Rear caliper pistons are grooved, and the inner rear brake pad has a stud on it, this stud must sit in the groove of the caliper. If it is not sitting in this groove the caliper will provide uneven pressure on the pad, and the pad will shift arround causing the clicking. I took the caliper off and saw it right away. Just had to re-align the stud and caliper by rotating the piston. Hopefully your situation is as easy as this. Autozone sells a $10 tool that you put onto a socket wrench to rotate the piston.