A booster actuator 10 may be positioned between the solenoid 12 and a valve 14, and increases the energy output from the solenoid to activate the valve. The booster actuator 10 may include a force input member 28 and a force output member 30 each linearly movable with respect to a body 20 from an initial position to an activated position. A coil spring 46 biases the input member to the initial input position, while a plurality of disk springs 48 bias the output member 30 to the activated output position. A plurality of linking members 32 each pivotable with respect to the body normally retain the force output member in the initial position, but upon movement of the input member to the activated position release the force output member in response to the disk springs.