Braking of road vehicles can be characterized as an active - either wanted or unwanted reduction of the force necessary for maintaining the required speed, decreasing the speed, stopping or keeping the vehicle at a standstill. During braking the vehicle loses the acquired motion energy which is most frequently transformed (in case of wanted braking) in the brake system of the vehicle into useless heat released to the environment. Brake force can be defined as the force acting against the motion of a vehicle which is, in case of wanted braking produced by the vehicle braking system. In case of wanted braking we usually begin with the equilibrium equation of vehicle forces. The paper deals with objective findings and assessment of possible causes leading to the braking system failure paying special attention to the brake lining. The user can approach the brake lining failure from two points of view: being aware or unaware of it. Laboratory tests can be used to objectively assess characteristics of brake linings. Both operational and laboratory test are performed to detect characteristics of brake lining materials. Apart from theoretical considerations, the paper also contains results of experiments performed with different brake lining materials used for trucks and passenger automobiles.