What does the coolant reservoir tank do?coolant over tank

Your car’s cooling system keeps your engine’s temperature at a healthy level. This prevents overheating, which can cause serious damage to critical engine components. Coolant is sent to the engine, where heat is absorbed and carried to the radiator where it is cooled down and prepared for re-circulation.

Since heat causes coolant to expand,  the excess or overflowing coolant needs to have a place to go. The coolant reservoir (or overflow tank) connects to the radiator and captures the overflowing coolant. This prevents coolant loss due to overflow. The coolant reservoir can usually be opened WHEN COLD, allowing you to top up your vehicle with coolant if it gets too low.


Learn more about how the cooling system works 

High levels of engine heat can sometimes cause the reservoirs exterior to warp or crack. This can result in leaks, which can starve your vehicle of coolant and increase the risk of your engine overheating. For this reason, it is recommended that you replace the coolant reservoir as soon as an issue is noticed. Overheating can lead to severe engine damage if left untreated.

High engine temperature can damage cooling system components such as the reservoir, water pumpradiator, hoses and head gasket. If the engine has overheated before, all cooling system components should be inspected for leaks in order to prevent further problems.

Warning: Coolant can become extremely hot and cause injury. For this reason, never remove the radiator cap while your engine is still warm.


Symptoms of a leaking coolant reservoir:

  • Higher engine temperature – When the reservoir leaks, coolant will exit the cooling system. This will mean that there is less coolant remaining to cool your engine down. If you notice that your engine temperature gauge is giving a higher reading than normal, or a engine temperature warning light is on the dash then a damaged cooling system reservoir could be the culprit.
  • Visible warping or damage to the reservoir – Upon inspecting the reservoir, you may notice that there are visible cracks or signs of warping. The coolant level may also be lower than normal, even after you top it up.
  • Coolant leaks beneath your car – Coolant can be identified by its bright colours (usually orange, pink, red, yellow or green). If you notice a puddle of coolant forming under your car, it is usually a reason for concern. Components such as the reservoir, hoses or water pump could be leaking.


Coolant Reservoir / Overflow Tank Replacement in Hamilton

Is your car in need of a new coolant reservoir? If so, we can help! At Grimmer Motors, our team of skilled mechanics can replace your coolant reservoir with a new one that is specially fitted for your car. This will prevent coolant leaks and overheating in order to greatly extend the lifespan of your engine.

For cooling system diagnostics and servicing in Hamilton, contact Grimmer Motors today!

Please Note – we don’t generally stock or supply just “parts only” for this service. We are a general automotive repair workshop. If you are able to bring your vehicle to us, we can diagnose the problem, find and fit the necessary parts, or organise the appropriate service for you.


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