Lesson 5/Learning Event 1
FIGURE 68. COOLANT PUMP CONSTRUCTION.
Automotive engines usually use a centrifugal (impeller) type pump that consists of a round plate which has
blades or vanes on one side of it. The plate, or impeller as it is usually known, is fastened to a turning shaft.
As the impeller turns, its blades will throw coolant outward.
The pump is completed by placing the impeller in a closed housing that has a coolant inlet at the center of the
impeller and an outlet at its outer edges. On some pumps, the impeller may be placed directly into the coolant
jacket of the engine instead of being enclosed in the pump housing. Then the cylinder block will serve as a
part of the pump housing.