The engine cooling system stabilizes the engine operating temperature by limiting the rise above the expected limits. The coolant is circulated by the water pump, which must ensure the correct flow at each engine speed.
Incorrect operation of the water pump can cause significant damage to the engine. For this reason it is extremely important that it is systematically checked.
In many applications, the water pump is controlled by the timing belt. Therefore, any replacement made during maintenance of the timing control system is extremely important.
The major elements that characterize the quality of Dayco water pumps are:
- The bearing: supports the impeller on one side and the pulley on the other side. This element must ensure constant smoothness and withstand the loads generated by the system. It can be a double ball bearing or a ball bearing (impeller side) and a roller bearing (pulley side). The determination of the bearing geometry is made by the engine manufacturer according to the loads generated by the system.
- The impeller: made of synthetic material reinforced with fibreglass, steel or cast iron. It is important that the profile of the impeller blades ensure the correct flow in order to avoid cavitation effects. The complex design of the impeller accommodates the constant flow of liquid at all engine speeds.
- The seal: mounted between the impeller and the bearing. At all operating temperatures and speeds, the bearing must guarantee the seal of the liquid to prevent it from entering the bearing, compromising the lubricated grease qualities and causing irreversible damage to the pump.
Another important element is the pump body: generally, in plastic or aluminium depending on the manufacturer’s choice. The pump body must guarantee the correct stiffness and geometry of the system.