First and second pistons are mounted to a common shaft which reciprocates during compression and suction strokes. During each of the strokes, fluid is pumped out at an outlet, via a one-way valve on the second piston. The one-way valve is opened or closed depending on whether the first and second pistons are in the compression or suction stroke. Additionally, pressure from the outlet assists in traversing the first and second pistons in the compression stroke. During the suction stroke, the fluid pressure applies a force on the first piston to counteract the fluid pressure on the second piston so that a smaller spring may be used. The size requirements of the solenoid and spring are reduced. Additionally, the fluid pump provides lower pressure spikes, since fluid is pumped out during both the compression and suction strokes and also provides a more even flow of fluid.