Hydraulic system

A hydraulic system comprising:

• a first hydraulic cylinder including a first piston, and a first volume chamber and a second volume chamber whose volumes change as the first piston advances or retreats;
• a second hydraulic cylinder including a second piston driven by the first piston, and a third volume chamber and a fourth volume chamber whose volumes change as the second piston advances or retreats;
• hydraulic oil filled in the first hydraulic cylinder and the second hydraulic cylinder;
• a transmission mechanism including a first connection pipe that allows the first volume chamber and the third volume chamber to communicate with each other and a second connection pipe that allows the second volume chamber and the fourth volume chamber to communicate with each other, the transmission mechanism transmitting a movement of the first piston to the second piston via the hydraulic oil;
• and
• a correction mechanism that corrects a position of the first piston by causing the first piston to advance or retreat in a state where the second piston is stationary;
• wherein the correction mechanism includes:
• a brake that regulates a movement of the second piston;
• a bypass pipe that allows the first connection pipe and the second connection pipe to communicate with each other;
• and
• a valve that opens and closes the bypass pipe.