Thumpin in front end while braking
 

93 F-150 4X4. When stepping lightly on the brakes to come to a stop there is a thumping noise from the front end. Braking a little harder makes the noise stop. The noise is only on the drivers side. I had the calipers off once and switched the clips that hold the caliper on with the ones from the passenger side and the noise stopped for a couple of days.

I think it would almost have to be a bushing, more than likely the axle pivot bushing. Anybody else experience this? Any tips on how to check the bushing?

Yeah mine does the same thing, except it don't matter how hard I brake.
Get under there with a good flashlight and eyeball the condition of the rubber itself. There is a steel sleeve thru the center of each bushing, if it appears off-center then the bushing is shot.

While you're at it, check the radius arm bushings too. Look closely at the bracket that the bushing mounts in, if the bushing is loose you'll see where it's been rubbing and has polished the surface of the steel bracket.

I put new radius arm bushings in it earlier in the summer. I never could find a diagram of how they were supposed to go back in, which bushing went on which side of the bracket. looking at the old ones wasn't much help, they were both flat and the poly kit I got had two different shaped pieces in it. Don't recall the brackets being loose either. I plan to get under there with a big Crescent wrench and see if there is any movement in either of the traction beams, as well as eye-ball the bushings.

I had new ball joints put in when I got it, the mechanic inspected the front end and said the pivot bushings were fine. He has done me right before, but I think I'll look anyway.