XCMG 860109755 Water Pump – Drawing 6QAJ-1307010, for Yuchai YC6105 Series

A water pump (also called cooling water pump or centrifugal pump) is the core actuator of a diesel engine's forced-circulation cooling system, mounted at the front of the engine block and driven by the crankshaft pulley via the fan belt . Its working principle: the rapidly rotating impeller generates centrifugal force, drawing coolant from the inlet into the pump chamber, accelerating it through the volute, and pressurizing it out through the outlet into the block water jacket, then through the cylinder head, thermostat, and radiator for heat exchange before returning—forming a closed loop .

A typical centrifugal water pump consists of a pump body, impeller, pump shaft, bearing, water seal, mechanical seal, pulley, and flange​ . The body is usually cast iron or aluminum alloy; the impeller, made of stamped steel, cast iron, or resin, flings coolant into the water jacket when rotating ; the shaft end carries a mechanical seal (rotating/stationary ring structure) to prevent coolant leakage along the shaft ; the pump body typically features a weep hole​ at the bottom—minor seepage here during early water-seal wear serves as a warning sign; continuous dripping indicates seal failure requiring replacement .