Master cylinder, method for manufacturing a master cylinder, and check valve system of the master cylinder

A master cylinder designed to facilitate an operation of assembling and adjusting a check valve is provided. A supply passage for supplying operating fluid from a reservoir to a pressure chamber is formed in a cylinder body connected to the reservoir . A bypass for bypassing the supply passage connecting the reservoir and the pressure chamber is formed and provided with a check valve system adapted to open when a pressure in the pressure chamber is lower than that in the reservoir . A valve case and a covering member constitute a cartridge , which accommodates a valve body and an urging spring , so as to form a check valve system . The cartridge is placed in a valve chamber of the bypass