Prestolite 21500-1 Hydraulic Pump Motor Assembly

The Prestolite 21500-1 is a 12-volt DC electric motor designed to drive the hydraulic pump on Western and Fisher snow plow assemblies. It features a 4-1/2 inch diameter frame, a tang-type slotted shaft for direct pump coupling, and clockwise rotation when viewed from the shaft end. The motor utilizes a four-field coil configuration for smooth torque delivery and incorporates two brass terminals for power connection. This motor serves as the primary actuator for raising and angling the plow blade on Insta-Act, UltraMount, and Minute Mount 2 hydraulic systems. Constructed with a sealed commutator end and corrosion-resistant housing, the unit is engineered for intermittent duty cycles in sub-zero environments. It replaces legacy motor assemblies including part numbers 21500, 21500K, 56363, 51048, 56133, and aftermarket reference 1306326. The assembly includes mounting hardware for direct installation on the pump manifold. Compatible with straight blade and V-plow configurations manufactured by Douglas Dynamics brands Western, Fisher, and Blizzard.