A liquid-cooled, radial air gap electric motor includes a stator, a rotor, a rotor shaft, two end bells, a housing, a coolant manifold system, and a coolant sump. The rotor includes a plurality of axially directed slots located near its periphery. The coolant manifold system directs a first portion of liquid coolant to flow past some portion of the stator and a second portion of liquid coolant to flow through the rotor slots. Some or all of the liquid coolant is received by the coolant sump from which the coolant may be recirculated.