Abstract: A dual component pumping system comprised of a double-acting air motor alternately driving reciprocal pumps. Mechanically operated pilot valves activate a spool valve which reverses the air motor operation. Each pump has an inlet connected to a separate fluid component supply tank and an outlet connected to a spray gun through flexible hoses. A valve switching arrangement permits switching from one fluid to the other. The valve switching allows spraying of a fluid received from one pump while the other pump is in a bypass mode and recirculates fluid from its supply tank.