What is a radiator cover? What’s the purpose of the radiator cover? What are the symptoms of a bad radiator cap?
What is a Radiator Cap and how does it work?
The radiator cap, a small mechanical part that controls the coolant pressure in the radiator, is very important. The radiator cap’s primary function is to prevent coolant from escaping from the radiator. However, there are other important functions that it plays in the operation and maintenance of the engine cooling system.
- The radiator cap increases the boiling point by keeping coolant under pressure. The coolant boils when it reaches a certain temperature. The boiling point of the coolant is about 100 °C. The radiator cap increases the boiling point of the coolant by approximately 7 °C.
- The liquid expands as it heats up. The radiator cap controls the coolant level and sends the expanding coolant to an expansion tank.
- Air is the enemy number one of cooling systems. It causes insufficient cooling, corrosion and damage to cooling system components. The radiator cap seals off the cooling system and prevents air from getting in.
What is the Radiator Cap?
The radiator cap, which is responsible for protecting the cooling system’s safety, has a simple operation. Different cooling systems require different pressures. Radiator caps are rated according to the pressure they can withstand (e.g. 0.9 bar or 15 PSI). Make sure you have the correct pressure for your vehicle when purchasing a radiator cover.
Coolant is usually made up of antifreeze and water in a one to one ratio. The coolant absorbs heat from the engine while the water and antifreeze increase the coolant’s boiling point. The undesirable process of evaporating the coolant is because it can either cause a complete system leakage or take up too much space. This will lead to excessive pressure, which in turn causes system damage.
The only place that this pressure can escape from cooling systems is the hood. A spring-loaded checkval is located under the cover. It opens or closes depending upon the maximum operating pressure. The spring opens the check valve when the system pressure is at the desired level. This allows coolant to escape through a thin tube into the expansion tank. The cap draws coolant back into system when pressure falls.
What are the symptoms of a defective radiator cap?
Defective radiator caps are one of the leading causes of cooling system problems. A defective radiator cap is most likely to cause:
1. Low Coolant / Coolant Leaks
Excessive pressure can build up in the radiator, causing leaks. The coolant will leak at the weakest part of the system if it is under pressure. Leakage could occur in the cover, gaskets or hoses, as well as the water pump and radiator.
To find the leak, warm up your vehicle. You can then examine the underside and locate the leak by carefully inspecting the hood. Different vehicles may use different types, so the fluid could be bright green, orange or red and yellow, or even blue.
These leaks can sometimes only occur at the operating temperature of the vehicle or after it has been used for a while. You may notice the coolant system under pressure leaking into your engine compartment or directly into your air.
Coolant levels will naturally drop if there’s a leak in your system. You should replace the coolant if the level drops below the recommended minimum level.
2. Engine Overheating
Engine overheating is another sign of a faulty radiator. The temperature gauge should be checked for rising temperatures. Once the temperature has dropped, it is a sign that the radiator cap is defective. The next step is to call for a tow truck to transport your vehicle to the nearest mechanic. Overheating the engine can cause damage to parts and the engine.
3. Radiator Hoses Collapse
The internal pressure fluctuations that can lead to hoses shrinking, bursting or collapsing can cause them to burst. A vacuum can be created when the pressure drops too low. This causes one or more of the hoses to burst or crack.
You should not feel the hoses too stiff or spongy when you inspect them. Spongy and weak hoses will collapse quickly, while rigid and strong hoses may crack under extreme pressure.
4. Overflow from Expansion Tank
The expansion tank is supplied with the cooling liquid. It expands through heating. An improper radiator cap can allow coolant to get into the expansion tanks, even when the conditions are not met. This can lead to an expansion tank overflowing and a delay in coolant circulation.
