Brent,

Your wheels will be warm from normal brake action and even from tire
sidewall flexing on the freeway.  Jack up the van, and if you can spin
each front wheel with VERY slight, if any, touching of the pads to the
disk you are fine.   Any binding and you have a bad caliper or warped
disk.  The rears should rub a little, kind of intermittently, but still
be reasonably easy to spin by hand.

I don't rebuild calipers any more, too many problems in the past. it is
best to buy high quality rebuilt units from a reputable production
rebuilder, IMHO.  The pistons in the calipers are retracted slightly by
the simple contraction of the rubber piston seal when the pressure is
released from braking, and any scoring, pitting, or corrosion in the
system can prevent this retraction.  Then heating from the dragging pad
or pads causes more pressure to build up and cause pulling to one side,
along with rapid pad wear.

Check it out, don't take shortcuts with your brakes!

Stuart