A linear pump assembly includes a cylinder piston disposed in a generally tubular internal cylinder chamber defined within a cylinder housing having first and second ends, a first plunger-cylinder rod securely coupled to a first end of the cylinder piston and disposed in a first generally tubular internal plunger chamber defined within a first plunger housing in linear alignment with the cylinder housing, and a second plunger-cylinder rod securely coupled to a second end of the cylinder piston and disposed in a second generally tubular internal plunger chamber defined within a second plunger housing in linear alignment with the cylinder housing and the first plunger housing. First and second fluid ends are coupled to the first and second plunger housings respectively, the first and second fluid ends each housing a suction valve and a discharge valve.