What may weaken the effectiveness of the front braking system of the motorcycle?

The motorcycle braking system shown in the picture is a hydraulic system, in which braking force is transmitted via pressurised brake fluid. A leak of this fluid from a leaking hose causes a drop in pressure in the system. Consequently, the force from the brake lever is not effectively transferred to the brake pads pressing against the brake disc, which leads to a significant reduction or a complete loss of braking force.