Pneumatic braking system is used in vehicles called heavy vehicles or heavy commercial vehicles. The air is produced with a tool called compressor and the air is discharged as soon as the brake is applied. Discharge of the air provides braking. In hydraulic systems, braking is not possible when the oil runs out. However, if air is discharged in air brake systems, the vehicle tries to stop. Accidents involving brake breakdown of heavy vehicles often occur in older vehicles. The most important reason for this is the wear or tear of the pads. Serious accidents can occur if the linings are not properly maintained. Another reason is that the air in the brake bellows does not drain for some reason, although it is not often encountered.