Where is the fill point on a coolant tank?
The type of coolant tank and the fill point location can vary depending on the system. In many modern cars the radiator is mounted lower than the engine. Since the radiator is lower than the engine a pressure relief and fill point that is higher than the engine is needed. This is accomplished with an expansion tank.
What causes a coolant tank to overfill?
In my experience the thermostat is the most likely cause of the overflow tank to overfill. The fluid is being blocked therefore it’s heating up to the point of actually boiling and then as it expands and the only place for it to go without causing a leak in the system is into the overflow tank and then overflowing out of that tank.
Is it normal for coolant to bubble up through filler neck?
It is often very normal for the coolant to “bubble up” through the filler neck as any trapped air in the internal cooling passages is forced out of the system.
What are the symptoms of a bad coolant tank?
Below are common symptoms that may appear with a faulty coolant expansion tank. As coolant gets hot due to it absorbing heat from the engine, the liquid expands and creates additional pressure in the radiator.
The type of coolant tank and the fill point location can vary depending on the system. In many modern cars the radiator is mounted lower than the engine. Since the radiator is lower than the engine a pressure relief and fill point that is higher than the engine is needed. This is accomplished with an expansion tank.
Where does the coolant go in an overflow tank?
With this form of system, as the system pressure is increased, excess coolant is forced out the radiator vent and into the expansion tank. As system pressure drops, cooling is drawn from the expansion tank and into the radiator and engine.
What happens to the filler neck of a radiator when it cools?
As the cooling system begins to cool down, the internal system pressure drops until it allows the pressure cap spring to overcome the system pressure and the cap then forms a seal again on the bottom of the filler neck. This takes place when the internal system pressure drops to lower than the rated pressure of the radiator pressure cap.
What happens when the coolant stops in an expansion tank?
At that point, the coolant flow will stop, making the expansion tank a closed system. This system will have no way to vent is pressure, about that of the radiator pressure cap rating, until the expansion tank pressure cap is removed. This can cause some problems with the expansion tank.