Aftermarket July/August 2022 Issue

C ooling systems are vital for the proper running of vehicles, whether they run on a conventional drivetrain, via a hybrid system or via battery as an EV. This means you need to keep up with the latest developments, but also maintain your knowledge of the basics. The radiator plays a central role in the proper functioning of most cars, as Nissens Marketing Manager Jan Zieleskiewicz observed: ”Any problems with the radiator can have catastrophic consequences on the engine and the overall reliability of the vehicle. There can be several reasons for radiator failure, but generally they are caused by external factors rather than because the radiator itself is defective. However, whatever the cause, coolant leaks, restricted flow etc, the result will significantly affect engine operation and may lead to its failure. Common problems Looking at common radiator problems, symptoms and root causes, Jan started with corrosion: “Aluminium powder and rust deposits at the radiator header plate, inside the radiator or at the inlet and outlet are likely to be caused by either the improper coolant, i.e., tap water/dirty water, or reused antifreeze. In addition, mixing different kinds of antifreeze, or not having the correct coolant mixture can also have similar consequences. External corrosion can also be a problem in areas subject to high levels of saline in the atmosphere, such as in coastal regions, or where there is a high use of road salt.” Next, he considered debris and deposits inside tubes: “Contamination such as scale, jelly-like substances or other debris/particle concentrations inside the coolant channels can again be caused by using the wrong coolant or coolant mixture, but can also be because of a failure to flush or improper flushing of the system prior to radiator replacement.” Surface soiling, Jan noted, can lead to insufficient heat exchange: “If the surface of the radiator is covered by contaminants, the air flow through its fins will be restricted and this will reduce its cooling efficiency. Likely causes include a lack of general vehicle maintenance, prolonged periods when the vehicle has not been used, oil/coolant leaks that cause the surface to become sticky and so attract debris/contaminants that cannot disperse during the normal use of the vehicle.” Then there is electrolysis: “Visible white powder inside the radiator or at its header plates, or greenish colours around fins and tubes can be as a result of a fault with the vehicle’s electrical system causing a current to affect the cooling system by initiating an electrochemical reaction.” System over-pressure can blow out the system: “Visible bursts or deformation of the radiator or related parts can be caused by a defective radiator cap, restricted flow within the expansion tank, a blown engine head gasket or improper coolant (its boiling point is too low), and are likely to result in coolant leaks.” 36 AFTERMARKET JULY/AUGUST 2022 COOLING www.aftermarketonline.net KEEPING IT COOL The pressure is on for cooling, as new developments make the system more vital than ever On how broken radiator threads can affect the system, Jan said: “Leaks/loose couplings within oil cooler fittings (if integrated with the radiator), can be caused by screw threads that have been stripped or damaged due to careless or improper service. This will naturally lead to coolant leakage.” Mechanical damage will also have an impact: “Visible surface or element damage and can result in restricted flow rates and coolant leaks and are often caused by careless handling during transportation, or because of a collision with another vehicle or some other unyielding object.” Solutions On how to avoid these problems, Jan said: “Inspect the radiator surface, cap, expansion tank and ducts on a regular basis. Use solely the coolant specification/coolant mixture prescribed by the vehicle manufacturer. Before installing a new radiator, a thorough inspection to establish what caused the previous part to fail, is required for the root problem to be solved beforehand. Once that objective has been achieved, the entire cooling system must be flushed. Then, inspect the vehicle’s electrical system and make sure the cooling system is not exposed to/in contact with a faulty current. Next, inspect the radiator cap, expansion tank and ducts, and ensure the engine head gasket is intact. Lastly, inspect the oil cooler Above: K-Seal Coolant Leak Repair will quickly and safely repair a fault