Overflow & Expansion Tanks
Radiator overflow and expansion tanks
Radiator overflow or expansion tank damaged or starting to leak or seep coolant? Gone that brown colour, so you can't see the coolant level? Get in-store or online today to find your replacement overflow or expansion tank with Repco. Offering you the most reputable brands, including Dayco, Swag, and AllCrash.
Popular Questions Asked
What does a radiator overflow tank do?
The job of a radiator overflow or radiator expansion tank in your vehicle's cooling system is to stop coolant from leaking onto the road. This is bad for the environment and makes roads slippery. It also means you are losing coolant, and your vehicle will eventually overheat. When an engine is running, the coolant is used to stop it from overheating. This means the coolant gets hot, and the expanding coolant needs somewhere to go. This is where the coolant overflow tank comes in. It gives the hot coolant space to expand without dripping onto the road.
Why do I need a radiator overflow or expansion tank?
The reason you need to replace these overflow tanks is a coolant leak through a cracked or damaged tank or a stained coolant tank, so you can't see the coolant level in the tank. This is bad as not knowing the correct level will force excess coolant out of the overflow onto the road, or not enough coolant will cause overheating, where the steam and gas pressure forces the remaining coolant out of the overflow and onto the road.
Pretty much all liquid-cooled engines use this system. Whether they are called a recovery tank, factory expansion tank or radiator overflow tanks, they all basically perform the same function. As cooling systems go through their heating and cooling cycles, the overflow tank typically allows the coolant level to rise and fall. Some have a pressurised radiator cap located on the tank, some have this cap on the radiator itself. Care must still be taken when hot, as the pressurised radiator cap can cause nasty burns from rapidly expanding coolant if not done correctly. Hot coolant fills are best avoided for this reason.
What are the signs my overflow or expansion tank is bad?
There is an array of different signs that indicate that you need a replacement overflow tank. Keep in mind some of these symptoms can occur if other cooling components are not working correctly. If in doubt, get in contact with your local Repco Authorised mechanic or get in contact with your local Repco store, who might be able to recommend a local mechanic.
- Notice coolant leaks
- Notice low levels of coolant and having to consistently fill up with coolant.
- Engine overheating
Our range of quality radiator overflow and expansion tanks
Coolant expansion tanks are vehicle specific and come in all sorts of odd shapes and sizes, and are usually made of translucent plastic so you can see the coolant level. At Repco, we have an extensive range of popular tanks in stock or you can order in units if required, so you get the exact tank you need. Browse our website to see our extensive range of cooling system products