Best thing to do is check the operation with the vehicle on jack
stands. Have someone apply the front brakes while the wheels
are off the ground. Obviously they should not turn. Have the
person release the brake and see if you can turn the wheel by
hand. If they turn with an ever so light drag, they are ok. Since
the vehicle is 16 years old, when the brakes were service in the
past, were the caliper bolts greased? When the bolts are tight,
they should allow the caliper to move freely sideways to release
the tension on the rotor. If not greased regularly (when pads are
changed) the caliper can bind up when the pedal is released.
Same process on the rear wheels.