Brake Assembly Help

A few weeks ago, I hydroplaned and hit a concrete barrier. The only part of my car that hit was my front left tire, not a scratch on the car. I did replace the wheel, as there was a huge dent in the rim. I've since noticed that when I brake, there is a thump, thump, thump sound and vibration that gets worse the harder I hit the brake. The car still stops fine, it just makes that annoying thump. It's not loud at all, I can feel it more than I can hear it. When I replaced the wheel, is took the caliper off, and two little pieces of metal came out, according to my Chilton, these were Shims, or shim clips. They are about the size of the "enter" button on a keyboard. I've been driving it(without the shim/shim clips) for about 2 weeks and decided to have another look. I noticed that my rotor has a small groove in the face, but it's a shallow groove on one side, and a deeper groove on the other(This is all on the outside face, the inside face appears to be fine). I'm not sure if hitting that barrier has bent something, and I hate to replace the rotors and pads, only to have the same symptoms. Any suggestions? I don't know where the shims/shim clips go, could not having these in the caliper cause my thumping noise? Any advice is appreciated, I'd like to fix it this weekend.

Oh, It's a 99 Ford Escort 2.0L Sedan

Well it is hard to diagnose a thump that you feel more than you hear...

How is the alignment?

With the shims removed it makes sense that the thumping you hear is due to the little bit of play that you have given the brake pads. Your Chilton's or Haynes book should show you exactly how they install... and I suppose you should also be able to see marks on the brake pads where the shims were at.

Sounds like for starters you should repair what you know is wrong. Replace the shims and retaining clips, have the rotor turned if necessary, and get an alignment if necessary... if you hit something hard enough to damage the rim then you most likely need an alignment. Make sure your new tire has been balanced too.

The allignment is just fine, no pull on the steering. The Chilton doesn't explain how the clips go on. I looked all over to find out where they looked like they went, but couldn't find it. I'll look at it again this weekend and see if I can figure it out.

to me it sounds like these are not shims, but brake clips that hold the pads in their upper and lower mating surfaces on the caliper braket, also, take your other tire off, and inspect, both side should be a mirror image of each other.