I'm not aware that any early WPs used an electric pump but I imagine someone will clarify if they did.
I know that the pump was at one point mounted on a pivot which connected to the agitate cam bar. Early suds models, the pump impeller was designed as bi-directional. The transmission pulley had a groove for the motor belt and also a rubber drive tire below the groove. The pump pulley had a groove and a flat part. Shifting into agitation pivoted the pump so the flat of the pump pulley pressed against the transmission pulley tire so the impeller rotated in "reverse" to suction the saved suds water, although the two-way valve also had to energize into suds return mode for that to occur, thus it didn't perform suds return during normal agitation. The pump pivoted the other way when agitation disengaged so the groove part of the pump pulley contacted the belt for the pump to spin in drain direction, and the suds valve controlled whether the drained water flows to storage or to the standpipe. Non-suds model had an adjustment so the pump pulley didn't contact the transmission pulley.
I'll bet a buncha of ya'll didn't know that. ;-)