GM Service Manual Online
For 1990-2009 cars only

    Object Number: 172134  Size: SH
  1. Inspect the linings when the wheels are removed (tire rotation, etc.). Refer to Tire Rotation in Tires and Wheels.
  2. Check both ends of the outer pad (2) by looking through the lining inspection hole in the caliper. These are the points where the highest rate of wear normally occurs. At the same time, check the thickness of the inner pad to ensure that the inner pad has not worn prematurely. The minimum thickness of the pad lining material is 2.5 mm (0.10 in).
  3. Replace the pads if the minimum thickness has been exceeded.