The present invention relates to a draining device for discharging the water contained in a fuel filter manifold, including a draining solenoid valve comprising a valve body (1′, 2′) provided with a draining channel (17′), a coil winding (10′), a piston (8′, 12′) arranged such as to be movable between a passive position for closing the draining channel (17′) and an active opening position allowing the water to be drained, the movement of the piston being controlled by the coil, characterized in that the valve body includes a first portion (1′) that is integral with the manifold of said filter, the coil (10′) and the electric circuit (3′) being embedded by molding in said first portion (1′) and a second portion (2′) removably mounted on the lower end of the first portion (1′) and provided with the draining channel (17′).