Improved method for cleaning a pump, fluid hose, and spray gun is provided by, for example, repeatedly changing the flow rate of the cleaning fluid pumped through the system to generate turbulence or increased turbulence and increased frictional resistance for enhanced cleaning action. A pressure control can cyclically vary the speed of the pump motor and pump connected thereto to generate the turbulence. The pumping cycle can alternate between a first and second power level and at a desired time interval for each speed. With a suitable solvent as the pumped fluid, the turbulence that is generated by the cyclical pumping action causes an increase in the scrubbing action of the solvent to quickly loosen residual material in the fluid passageways.