Fixed a brake problem I myself caused, a while ago. The calipers were rattling because the "bow" springs that hold tension on the caliper pins were shot. New springs, pins, etc, rattle went away. But I re-installed the driver side caliper the wrong way. It's easy to do; I actually read about this problem years ago on a Saturn site; happens to a LOT of them for some reason. If you don't disconnect the line, and you "flip" the caliper the wrong way as you put it back in position, the flex hose loops in the wrong direction:
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The hose is supposed to loop in an upward arc, not downward like ^^^^^ that. The was it was, it can restrict fluid flow. In my case, it restricted BACK-flow, so the caliper wouldn't retract properly when you let go the pedal. I had it on a cross-town highway run the other night for the first time in a long time, and I'm noticing a lot of wheel shake, and a distinct smell. No pull, oddly. Felt the rims when I parked it, and the LF is HOT. Peeked/poked around, and I saw how the line was going the wrong way. So I took a low-speed surface route home, no problem. Next night I pull the wheel, flip the caliper back to re-orient the hose:
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(you don't have to disconnect it; you just "flip" it 360 degrees), Sil-Glyde the sliding surfaces and put it back together. Up to 65, no more shake, park it and the wheel is totally normal temperature.
This is an easy mistake to make, and can drive you crazy, because it can cause just a partial restriction (caliper wasn't totally stuck), and it doesn't really look like anything's wrong until you look at both sides. Like I said, if I hadn't read about this with the Saturns, I probably woulda looked at it and not "seen" anything amiss.