A programmable microcomputer controlled load sensing system for maximizing the cleaning efficiency of particulate raw materials such as sand, gravel, rock, ores, etc. in a log washer by sensing the weight of the aggregate in the log washer tank and adjusting the angle of inclination of the tank for cleaning efficiency. The system includes a log washer tank pivoted at its lower end and supported by hydraulic cylinders at its upper end. A high/low pressure sensor detects changes in the weight of the load by changes in hydraulic fluid pressure communicated to the microcomputer, and raises or lowers the upper end of the tank when the programmed low or high pressure limits are exceeded through solenoid activated hydraulic valves.