brake 'n'

I need help desperately. Every morning I enjoy going to work not only because my job rocks, but because I love the sound of my Bronco in the morning, I dont even sit in it when I start it, just so I can get the full affect . On my way home last week I decided to stick my head out of the window and get some air but when I did I heard a rattle, yeah I gasped and pulled over to see what was going on with a flashlight and mini mirror I found nothing, but on the way home the rattle was still there and only went away when I hit the brake.
As far as I can tell it's my driver side brakes I took the wheel off to see what I could the pad is loose you can move it back and forth. I spoke to one of my friends who plays with f series trucks he said it was no problem that it was normal, on the other hand another sand fanatic told me that your brakes are meant to move.
Help, is this as simple as removing my brake assembly and putting it back together or should I take it into a shop.
logistics:
93 ford bronco
stock rims and brake assembly
I had the brakes replaced about four months ago
"ford the only way to fly"
Thank you for anything you can do to help

hhmmm, my guess would to check the back (inside side of the rotor) brake pad and see if you lost your anti-rattle spring. that would be my first guess.

Check your hub caps or center pieces. I had a bad rattle on my bronco, and it had me stumped for the longest time. Had many ppl tell me it was the brakes and the calipers sticking, so i checked it all. One day i was just looking at it, and bumped the center hub cap, and it made the same noise. Check that first and tighten up the screws, it could possibly be it.

Yeah, i had the same problem with the little hub cap thingys too. They kept losing screws, unfortunately whenever i replaced them with ones from the hardware store they kept falling out. Finally i went to Ford, paid 8 bucks for 3 new screws, and they havent fallen out yet