A valve assembly for a pump driven by a motor is provided. The motor has an output shaft for driving the pump. The valve assembly includes a valve element concentrically attached to the output shaft of the motor. The valve assembly includes a gear set mounted on the output shaft of the motor. The gear set provides a motive force to the valve element through the output shaft for axially translating between an open position and a closed position on the output shaft. A spring located between the gear set and the valve element biases the valve element against the motive force provided by the gear set.