Vacuum boosters with master cylinder assemblies for engineering machinery brake system

The utility model discloses vacuum boosters with master cylinder assemblies for an engineering machinery brake system. The brake system comprises the two vacuum boosters with the master cylinder assemblies, each master cylinder is provided with an oil inlet joint (4) and an oil outlet joint (5), a piston assembly (12) is arranged in each master cylinder, each vacuum booster (14) is connected with a pedal mechanism through a connecting rod (15), the oil inlet joints (4) are respectively connected with an oil pipe, the oil outlet joints (5) are connected with a left wheel brake and a right wheel brake of a brake axle respectively, the two master cylinders are respectively provided with a balance oil port, and the two balance oil ports are communicated through balance oil port joints (7) and balance connecting oil ways. According to the technical scheme, the problem of imbalanced pressure of oil outlets is solved through the arrangement of the balance oil ports, synchronized braking of left and right wheels can