If your brake pedal seems to be "sticking", check your rear brake pedal clearance, to be sure it isn't rubbing on the bottom of the muffler. The muffler has an indent to clear the brake pedal, but the muffler bracket can gradually sag over time, allowing the muffler to contact the pedal arm.

Experience has taught me to avoid trying to undo the bolts holding the bracket to the muffler. They tend to rust in position, and the fix after you snap them off is to drill out the bolts and replace the threads with inserts. However, I've discovered that the brackets will bend, and can be adjusted back to rotate the muffler up slightly.

Place a piece of flat mild steel (1/8" to 1/4" with a straight, clean edge) in a vice, and rest the bracket (still attached to the muffler) over the steel support with the bend right over the edge. Now, tap the end of the bracket with a soft mallet, and it will straighten out slightly, repositioning the muffler back to it's original position.

Of course, the rear brake switch does get sticky, too. You can test it by reaching your fingers down and feeling the little rod extending and returning freely. I've drilled a tiny hole in the top of the switch between the two wire attachment lugs. I squirt some WD-40 down the hole, flushing out grit and cleaning the contacts. The hole is covered by the rubber boot on top. If the switch isn't working, it's easy enough to replace--well, if your fingers are small enough.