Fluid cylinder for activating an element of a drivetrain of a motor vehicle. The fluid cylinder has a cylinder housing and a piston. The piston is sealed off from the cylinder housing by means of a piston seal. At least one fluid chamber is formed between the cylinder housing and the piston, which fluid chamber can be connected via at least a first fluid connection to a fluid supply device. The piston in a piston stop position rests against a stop surface of the cylinder housing. The first fluid connection is formed in the region of the stop surface of the cylinder housing. The piston is connected to a sealing device which seals off the first fluid connection in the piston stop position.