Bosch Hydraulic Brake System Inspection
Before checking lining wear with the wheel removed, review the following brake lining exposure warnings.
Warning: Breathing brake lining dust (asbestos or non-asbestos) could cause lung cancer or lung disease. Unless exposure can be reduced below legal limits, wear an air purifying respirator approved by MSHA or NIOSH at all times when servicing the brakes, starting with removal of the wheels and continuing through assembly.
To minimize the possibility of creating airborne brake lining dust, clean the dust from the brake rotor, brake caliper, and brake assembly, using an industrial-type vacuum cleaner equipped with a high-efficiency filter system. Then, using a rag soaked in water and wrung until nearly dry, remove any remaining dust. Do not use compressed air or dry brushing to clean the brake assembly.
- Check lining wear, as follows.
- Apply the parking brakes. Chock the tires to prevent vehicle movement.
- Remove one or more of the lining inspection plugs, and measure brake lining thickness.
- On front and rear axles, replace linings worn to less than 1/16 inch (1.6 mm).
- Make sure that the brake rotor and linings are free of oil and grease.
- Install the inspection plug(s).
- If the wheel and hub assembly is removed from the axle, check lining wear. Replace the linings on all brake assemblies if worn to less than 1/16 inch (1.6 mm) at the thinnest point. Check the brake pads for wear and replace, as necessary.