I don't know how many people know about this, I just learned about it myself when it happened on my rig. Apparently, there is a VERY minor design flaw in the axle gaskets where if they aren't shimmed up just right during construction and assembly, it can wear against the wheel hubs and brake linings, causing it to rupture (split, blow-out.. whatever you want to call it). The resulting leak or seep will coat your break pads & shoes to the point where they can heat up and stick to the wheels.
Thankfully it happened to me while still under full warrantee, but for those of you who are near or past yours, you probably want to take a look for it. The first time I even heard of this problem was during a change from winter to summer tires when the mechanic noticed seepage stains on the hubs.
No for the pessimists in the group, I still firmly believe that I own one of the best trucks out on the market today (and so does my mechanic incidentally). But with all vehicles, there are always minor things to work out, expecially when the design is less than 5 or 6 models old. And if this is the worst my Tundra has to offer, I'll be happy for many years to come!