Maintenance 117 Brake Linings DANGER Before measuring the brake linings, set the parking brakes, place the transmission in neutral and block the wheels. Failure to do so can result in unexpected vehicle movement and can cause serious personal injury or death. Measure the brake lining thickness. If the brakes are equipped with backing plates, measure through the inspection holes in the plate. Reline the brake shoes if the lining thickness is 1/4 in. (6 mm) or less at the middle of the shoe. Check the brake drums for any visible cracks or signs of oil or grease. W7001278