Alabama CDL General Practice Test

Air brake systems rely on compressed air to operate. The air compressor generates that pressure, the reservoirs store it so braking can occur even as engine speed changes, and the air lines to brakes deliver the pressurized air to the brake actuators. The fuel pump, however, belongs to the engine’s fuel system and has no role in generating or delivering air for the brakes. So it isn’t a component of the air brake system, whereas the other items directly support the braking process.