The Cooling System
Vehicle cooling system maintenance is as essential to maintaining the engine oil. Unless otherwise, you own a vehicle with no cooling system like the Beetle-Volkswagen.
Have you been keen on checking your radiator tank for sufficient water? Mind it just this part of your car contributes an important role in the life of your engine.
Ignoring the proper maintenance of this system will bring you to a more costly and laborious situation.
How does the Cooling system Work?
The combustion inside the cylinders of your car produces temperatures high enough to melt the cylinder block in 20 minutes. A third of this heat is converted into mechanical energy to drive the car. Half of the waste heat goes out of the tailpipe.
But the remaining half has to be handled by the cooling system. The cooling system gets rid of engine heat by circulating a coolant through passages in the engine block. The heated water is then circulated through the radiator where it gives off heat.
As a rule, there is only a few degree difference between “too cold and too hot” when these terms are applied to engines. Extreme means either greatly accelerated wear or possible failure of wear parts within a very short time. Also, there are side effects such as increased fuel consumption and increased the formation of the sludge, gums, and corrosive acids that damage parts.
Remember however that the main purpose of the system, whether the indirect (water cooled) or the direct (air cooled), is to remove excessive heat and maintain the proper working temperature of the engine.
Obviously, a cooling system designed to operate under a specific pressure will not perform properly unless that specific pressure is maintained. For this reason, never install a pressure cap of a higher or lower rating than that allowed for when the system was designed.
Replace a pressure cap with one rated the same as the original one. A cap with a lower pressure rating may cause coolant to boil, causing a build-up of excessive pressure which may rupture a weak spot, possibly a blown hose or even a gasket.
In a conventional cap, two gaskets are used: one at the end of the spring-loaded pressure valve and another around the perimeter of the cap to keep air out of the system. Both gaskets are made of synthetic rubber and can be replaced only by changing the whole cap.
If your engine is operating at normal temperature, avoid removing the radiator cap as a part of routine servicing. It’s not necessary. Removing the cap will change the cooling system pressure and lower the coolant boiling point. Remove the cap only when the engine is obviously overheating, or when the cooling system needs servicing.
Coolant Overflow Tank
A plastic overflow tank often has markings that indicate the required water level. In general, the open end of the return hose at the radiator must be submerged in a coolant at all times. Check with the engine running at the idle speed. If it is necessary to add water, remove the cap from the overflow tank only. lack of sufficient coolant in the overflow tank can lead to malfunction of the cooling system.
Cooling System Leak Test
Leaks can create aeration damage. Any leak in the system can damage the water pump. If the leak allows air to get in, the air suction will cause the coolant to fill up with bubbles. These bubbles strike against the pump blades strongly enough to cause damage. To check if there is air in the system, here is a simple test you can do:
1. Warm up the engine.
2. Tighten all hose connections.
3. Fill up the radiator to specified coolant level.
4. Exchange the pressure cap on the radiator with a non-pressure type (a pressure cap without spring).
5. Attach a hose to the bottom of the radiator overflow pipe.
6. Put the other end of the hose into a jar of water.
7. Finally, run the engine at a brisk idle while in neutral.
You will see a steady stream of bubbles in the water jar if aeration is taking place in the cooling system.
Checking Radiator Hose
In most cars, a two-wire screw type radiator hose clamp or a strap-and-screw type instead of the usual spring clamp and the strap screw type should be tightened periodically.
Upper radiator hose should be neither brittle nor spongy. To check, pinch or squeeze the hose with the fingers. The hose should return to its original shape the moment pressure is released. Many cooling system failures are due to a swollen or cracked hose and loose connections.
The lower radiator hose may be checked by accelerating the engine. This trouble may not show at idle engine speed. A deteriorating hose may drop bits of rubber into the system and this can plug passages. Replace a defective hose as soon as possible.
Coolant Quality Check
Rust or scale in the coolant can wear away the pump shaft or pump blades or block inlet or outlet passages. There should be no excessive deposits of rust or scales around the radiator cap or radiator filter hole. Coolant should also be free from oil and other liquids that may cause contamination. If the coolant is excessively dirty, the best solution is to flush the system to get rid of rust and scale.
To do a quick and easy check to determine if the pump is working:
First, warm-up the engine at idle speed.
Second, squeeze the upper hose midway between two connections.
Third, let somebody accelerate the engine while you are squeezing the hose. If you feel a surge on the hose when the engine is accelerated, the pump is at least working although this test doesn’t show how well.
How to Flush the Cooling system
Remove the radiator cap and open the petcock at the bottom of the radiator. When coolant has drained off, tighten the petcock. Fill the radiator with plain water.
Start the engine. While the engine is idling, open again the petcock and insert a garden hose into the radiator filler neck. Wait about 5 minutes then remove the hose and tighten the petcock.
Finally, don’t forget to check your radiator if it is filled with water. Make it your regular or daily routine to inspect before you leave for a trip. Of course, this is applicable to the old model cars. The advance car models of today do not need necessary water maintenance as the old cars. Nevertheless, it should be an inherent action of a car owner to ensure what is needed to be done.