Abstract: Disclosed herein are a sealing member for a master cylinder and a master cylinder having the same. The master cylinder is configured such that a communication hole of a piston is rapidly brought into communication with an oil path toward an oil tank upon release of braking. This may minimize meaningless retracting movement of the piston and delay in a braking release operation. The sealing member for the master cylinder includes an outer wing part to come into contact with the cylinder body, and an inner wing part to come into contact with the outer surface of the piston. The inner wing part includes a seal formed at a tip end thereof and at least one oil passage formed in a surface thereof opposite the outer surface of the piston.

Abstract: Disclosed herein are a sealing member for a master cylinder and a master cylinder having the same. The master cylinder is configured such that a communication hole of a piston is rapidly brought into communication with an oil path toward an oil tank upon release of braking. This may minimize meaningless retracting movement of the piston and delay in a braking release operation. The sealing member for the master cylinder includes an outer wing part to come into contact with the cylinder body, and an inner wing part to come into contact with the outer surface of the piston.

Abstract: A brake booster for vehicles prevents suction noise that is generated from a rapid inflow of air from being emitted to the outside. The brake booster includes a casing, a diaphragm mounted in the casing by which a constant-pressure chamber and a varying-pressure chamber are isolated from each other, a valve body one end of which is fixed to the inner surface of the diaphragm and the other end of which includes an air suction area, a poppet valve mounted in the valve body to connect or disconnect the varying-pressure chamber to the outside, an input shaft one end of which is arranged in the valve body to operate the poppet valve, an output shaft transmitting to a master cylinder the force boosted by the pressure difference between the constant-pressure chamber and the varying-pressure chamber, and a noise barrier mounted in the valve body.