Dayco Coolant Overflow Bottle - DOT0036 suit Holden Commodore VS VR VN

Coolant Overflow / Expansion Tank

Don't lose your cool(ant) and ensure your cooling system is functioning correctly with the correct coolant expansion tank or coolant overflow bottle on your vehicle. Both units operate in differing capacities and it is vital you replace with the same.

A coolant expansion tank operates under pressure and is highest point in your vehicles cooling system. Coolant will continuously cycle through the tank and requires a pressurized cap to keep the liquid contained. Overflow tanks on the other hand are used to recover the coolant that escapes past the pressure cap on the radiator due to rising pressure and temperature. In a properly operating cooling system the coolant will then be siphoned back into the radiator as the temperature drops and operating as a fully self contained closed system. Over time these coolant overflow or expansion tanks will become discoloured, brittle, contaminated with sludge or even break requiring immediate replacement for the cooling system to continue effective operation.