The rear brake pads may be inspected without removal. With the rear end elevated and supported, remove the wheel(s). View the pads, inner and outer, through the cut-out in the center of the caliper. Remember to look at the thickness of the pad friction material (the part that actually presses on the disc) rather than the thickness of the backing plate which does not change with wear.
Remember that you are looking at the profile of the pad, not the whole thing. Brake pads can wear on a taper which may not be visible through the window. It is also not possible to check the contact surface for cracking or scoring from this position. This quick check can be helpful only as a reference; detailed inspection requires pad removal.
After the pads are removed, measure the thickness of the LINING portion (NOT the backing) of the pads. It must be at least 0.08 in. (2mm) for all 1992–95 Monteros. This is a Mitsubishi factory minimum; please note that local inspection standards enforced by your state must be given precedence if they require a greater thickness.