Purpose of the header tank?

[dr knockers]

Im aiming for a clean looking engine bay in my mk5 cortina, looking to remove the header tank and either loosing it completely or hiding it in the wing somewhere?




Do i really need it, from what i understand its just a container for when the rad pressure builds up to much?

Many thanks in advance

[Lemon-Ade]

It's not a pressure tank is it, only a loose fitting cap? The rad has a pressure cap and that tank is only for catching any over pressurised water that escapes, and there is no pipe to return it to the system? Think its before header tanks where common.

Ade

[JFB Tech]

On this type of header tank or more correctly "expansion tank", the pressure cap is on the radiator.  As the coolant in the system expands on heating, it blows past the cap and into the tank.  The tube in the top of the tank goes to the bottom.  Once the coolant cools and contracts in the cooling system, it sucks coolant past the pressure cap and refills the system.  The header tank does not necessarily need to be in the engine compartment but it does need to be there.

[dr knockers]

excellent, all i need to know!! Many thanks