Toyota Repair: 99 Tacoma Prerunner brake pads/calipers, caliper brackets, tacoma prerunner

Question
We have a 99 Tacoma Prerunner, automatic, 2.7 liter, power brakes, 47k miles...my question is this:  Why would the front brake calipers seize only on the inside half of the caliper?  The outside brake pad moves in and out easily but the inside pad is not being pushed out to meet the brake disk-it is literally frozen in place.  It must have been like this since factory, as we are the second owner and it had very low mileage when we bought it.  It doesn't look like the pad in question has ever moved-the other pad is worn about half, but the one that is frozen has no wear at all. We are also concerned that the other side might also be bad (didn't work on that side yet) because we have never felt any pull to one side or the other when applying the brakes.

Answer
This is a two piece caliper that uses sliding pins to move the caliper as the brake pads wear, the part of the caliper that contains the pistons seems to be sticking on the sliding pins, try removing the 17mm size bolts on the calipers, not the ones on the caliper brackets that mount to the steering knuckle, remove the pins, if they can't be pulled out they are seized and that's the problem, you may be able to remove them by spraying a rust penetrating spray and working on them to get them to loosen up to get them out, then clean them of all rust and lubricate and reassemble everything.