What should a driver check regarding the brake drums or rotors during an inspection?

During inspection, check the BRAKE DRUMS (or rotors): they should be free of CRACKS; not worn beyond safe limits (excessively worn/thin drums can crack or fail under heat); and FREE of oil, grease, or other contamination (which reduces friction and braking effectiveness). CDL air brakes inspection. ALSO CHECK: brake linings/pads (not worn too thin, not contaminated, securely attached); brake chambers (secure, not leaking, same size on the same axle); slack adjusters (proper adjustment); hoses/lines (no damage/leaks); the S-cam and return springs. Cracked, worn, or contaminated brake components are serious safety hazards and common violations. Knowing to inspect brake drums for cracks, wear, and contamination is commonly tested.