Engine cooling system

Radiator

The radiator is responsible for transferring heat from circulating coolant to the air. Heated coolant flows intothe radiator from the engine. Coolant is passed through a series of tubes and fins that effectively dissipate heat in the coolant.

Radiator Cap

Modern radiator caps are actually pressure valves that are responsible for increasing and regulating cooling system pressure. Increasing cooling system pressure raises the coolants boiling point. For every additional pound of atmospheric pressure, the coolant boiling point increases 3° F.

Coolant Radiator Cap

Modern radiator caps are actually pressure valves that are responsible for increasing and regulating cooling system pressure. Increasing cooling system pressure raises the coolants boiling point. For every additional pound of atmospheric pressure, the coolant boiling point increases 3° F. Coolant flowing through the hot engine transfers combustion heat to the fluid for dissipation in the radiator. In addition to providing improved performance over tap water, most leading anti-freeze products contain anti-rust and corrosion additives that prevent sediment build-up and premature cooling system component failure

Fan

The fan pulls cool air through the radiator to aid heat transfer from the coolant. Bent fans should be replaced.

Fan Clutch

The fan clutch is designed to keep the optimum airflow through the radiator. At slow vehicle speeds, the fan is required to move enough air through the radiator to insure proper cooling. At highway speeds the airflow through the radiator is sufficient to provide proper cooling without the aid of the fan. The clutch lets the fan free wheel at highway speeds, reducing horsepower loss.

Belts

Belts are responsible for driving the water pump and other accessories. Be sure they are in good shape and properly tensioned, not worn, cracked or slipping. Always replace worn belts. Over tensioned belts put unnecessary side-load pressures on the water pump impeller shaft and bearings. Premature water pump failure is likely.

Tensioners

Automatic tensioners are responsible for keeping the belt at the proper tension. Worn tensioners will jump and vibrate during normal engine operation. A vibrating tensioner causes shock waves to be transferred to the water pump shaft and bearing, causing water pump failure. Replacing the automatic tensioner when you replace the pump is good preventive maintenance.

Hose

Radiator hoses are responsible for carrying coolant to and from the engine from the radiator. They should regularly be inspected for signs of deterioration such as bulging and cracking. Healthy hoses should be pliable, not soft and spongy, or hard and brittle. Any sign of leakage could mean it is time for replacement.

Thermostat

The thermostat is responsible for regulating coolant flow into the engine block. It keeps the engine block at optimum operating temperature. When the engine is cold, the thermostat closes to restrict coolant flow and allow the engine to quickly reach a satisfactory operating temperature. As the engine heats up, the thermostat opens and allows more coolant to circulate. A sticky thermostat can stop or restrict coolant flow to the engine.

Water Pump

The water pump delivers a continuous flow of coolant through the radiator and through the engine. A paddle style impeller mounted inside the water pump housing, rotating on a bearing supported shaft, is responsible for moving the coolant. The impeller shaft is driven externally by a pulley/belt combination connected to the crankshaft pulley. Keeping the coolant clean and fresh is about all the maintenance a water pump requires. The cars cooling system dissipates about 30% of the heat generated by the engine. Coolant circulating from the radiator through the engine does the job. It is the water pumps job to deliver a continuous flow of coolant. Most pumps have six components: The hub is attached to the bearing assembly and connects to the source of power (a belt and pulley or sprocket) rotating the impeller. The housing is typically made of cast iron or aluminum. Hytec uses quality cast aluminum with no flashing. Vehicle manufacturers are moving to aluminum to reduce vehicle weight. Some newer engines have stamped steel housings.
The impeller is the mechanism that pumps coolant throughout the system.

The bearing assembly supports the continuous rotation of the impeller. It has two sets of bearings: one near the front of the shaft and one near the rear. The bearing can be either the ball or needle style. The seal protects the bearing assembly from coolants and contaminants.

The gasket insures a tight, leak-free interface between the shallow impeller cavity (where coolant collects) and the housing body.