I just did the rear brakes and parking brake components on my 4Runner, and I thought that I had them too tight when I put everything back together and took it for a test drive, stopping a few times, a couple hard stops.
When I got back, took the wheels off, and they spun totally freely. So even if the adjustment is too tight, everything should loosen up and be good to go.
You can put the back in the air, and pull the rubber plugs out and adjust them to be loser if you still think this is a problem. Just get a headlamp so you can see the gear in there, and use a flat-head to push the gear away from you, toward the outside of the truck and to the top of the truck, if you're sitting under the spare tire.
Like someone said above, I would guess our parking brake is engaged. When the handle is not engaged at all, the adjustment bolts should be touching the back plate. If they are not, then the shoes are prematurely engaged.
Also, bleed your whole system if you haven't already.