Automotive Cooling System
The cooling system on a most vehicles is an air / coolant design type, proper operation of the cooling system depends on a method of coolant releasing heat from an engine to the outside air. The radiator holds a portion of the heated engine coolant and then releases / dissipates heat through a series of extremely small vents along the radiator cores.
An older cooling system design is called the down-flow type. A down-flow radiator has a top tank and a bottom tank with flow tubes connecting them. Between the tubes are small thin metal fins that dissipate heated coolant to the outside air. Heated coolant flows into the top tank and circulates through the tubes to the bottom tank returning coolant to the water pump. Down-flow radiators are still used for large trucks that do not require low profile hoods.
Most vehicles today use a newer cross-flow radiator design. Cross-flow is the side to side movement of the coolant through a radiator. Cross-flow designs provide a greater area for heat dissipation while allowing more low profile hood designs.
Cross-flow radiators are similar in operation but instead of a top and bottom tanks, they use left and right tanks on the sides of the radiator. Heated coolant flows into the inlet on the top of one side of the automotive radiator then through the tubes connecting the side to side tanks and out of the bottom of the opposite side tank.
Radiators are subject to internal flow restrictions due to improper maintenance. Coolant must be changed regularly to prevent build up of deposits created by the breakdown of engine coolant chemicals and minerals. A radiator that becomes clogged due to deposits can only be cleaned by dis-assembly and physically cleaning out each individual tube. Normal flushing will not usually clean out accumulated deposits. It’s also important to keep radiator cooling fins clean and clear of debris to allow proper airflow. Be careful not to mount vehicle accessories that could block air flow across the radiator. Basic physical inspection of the cooling system can be as simple as removing debris such as leaves, twigs, and bugs from the face of the radiator.