The invention relates to an air brake system heat dissipation and maintenance functions. A multifunctional unloading valve is connected with a heat dissipation and maintenance air reservoir with a pressure meter and a brake air reservoir with a pressure sensor respectively through a two-position two-way electromagnetic directional valve and a two-position three-way electromagnetic valve. The two-position three-way electromagnetic valve is further connected with the heat dissipation and maintenance air reservoir on which a replaceable connector is connected. The heat dissipation and maintenance air reservoir is connected with a hydraulic oil pressurizing cylinder through a two-position two-way manual opening valve. The hydraulic oil pressurizing cylinder is connected with an oil supplementing tank and a maintenance press. An air outlet sieve is arranged between the multifunctional unloading valve and the two-position two-way electromagnetic directional valve, and a heat dissipator with a temperature sensor is adjacent to the air outlet sieve. The air brake system has the advantages that needless compressed air can be fed onto the heat dissipator through an overpressure air outlet of the unloading valve, energy is effectively utilized, heat dissipation capability is enhanced, oil temperature is lowered, working performance of the whole machine is improved, and the air brake system is convenient for field maintenance, simple to operate, safe, reliable and easy to implement.