Check for old/clogged hoses. This would really affect both rears rather than just one, but it could affect only one front. If you can get the brakes to obviously stick, open a bleeder to see if they release.
Look at the attached pic for an example of a grooved backing plate just in case you are unfamiliar with them.
Hate to state obvious, but for the rear, check that the parking brake is not overly adjusted, or that a cable is not sticking. Make sure the parking brake strut bar moves freely. Unless you have a posi rear, one side will stop spinning even when all is working correctly.
Also check for overloaded/bent plates. You mentioned that the shoes in the rear were shifted back after you took the drum off. Look at the top pivot to see if the shoes line up parallel on it. They almost never will, but check them against the other side. Check this in the front too.
A backing plate bent in this way will cause a low pedal if brakes adjusted with drum on. If doing a drum-off adjustment, it may show up as having to back the adjuster off significantly to get the drum on, and shove forward to get the lugs to line up to the drum. I see this mostly on the rear of trucks/vans w/o full floating axles. I don't have a spec on it, but as long as you can adjust the shoes to the drum while off, and then install the drum without shifting (therefore applying) the shoes to line up the lugs, it should be OK.
It seems almost wierd that it's suddenly one front and one rear opposite. I hope this might help.
Last edited by yesgo; 05-13-2006 at 12:11 AM.