Tom,

The caliper slides are the sleeves that the bolts that hold the caliper body
in place pass through.  The bolts should be shiny clean and lubed with
either caliper grease, wheel bearing grease, or anti-seize.  The bolts pass
through sleeves in the caliper body, and you should be able to push the
sleeves in and out of both sides of the caliper body up to the limit of the
rubber boots that hold the sleeves in place.  People often clean up the
bolts but forget the sleeves.  If the sleeves do not move freely, carefully
pull back the boots and see if you can use a dowl to push them out and get
the inner and outer diameter cleaned up and lubed with the same stuff you
use on the bolts.

The keyway that the square tabs on the pads sit in should also be clean - I
use a wire brush in a Dremel tool to clean up the keyway.  The danger of
using a file to enlarge the keyway is that you can get a clicking or
knocking noise when you apply the brakes or when you change direction and
apply the brakes.  While it is not dangerous, it is annoying, and the tab on
the pads can jam in the keyway and eventually cause a pulsation.  I have
seen this problem with some aftermarket pads, which is one more reason I
always recommend OEM brake parts.

I know that people often use aftermarket parts because they perceive them to
be of similar or equal quality to OEM parts for less money, but in my
experience, the way that aftermarket parts fit and perform is hit-or-miss -
an aftermarket brand can be great on some applications and terrible in
another, so if Acme widgets worked great in your Corolla, they may not be so
great in your Camry.  I sometimes use aftermarket parts, but stick to OEM
for brake parts, ignition parts, and oil filters.