Keeping your engine running at the correct temperature helps to prevent damage caused by overheating, and your coolant is an essential part of your cooling system.
You need to periodically check and refill coolant in your car to make sure it stays at the correct level in your radiator.
Before you get started, make sure you’re familiar with radiator safety. You also need superior coolant. Natrad can advise you on exactly the right products and methods you need to keep your car performing at its highest level.
Watch the video or keep reading for step by step advice on changing coolant.
What you’ll need
Make sure you have everything you need on-hand before you get started. To refill your coolant, you’ll need:
- Distilled water (if coolant is not pre-mixed)
- A funnel (optional)
Using a 50/50 mix of water and coolant is usually recommended. Check your owner’s manual to make sure you have the right type of coolant. Using a funnel isn’t essential, but it can help you avoid spillage.
How to refill your coolant
Refilling your coolant is a fairly simple car maintenance task you can do yourself, as long as you follow the right steps. Before you start, always make sure your engine is switched off and cool.
Follow these steps to refill your car’s coolant:
1. Check the coolant level
Your coolant reservoir should be labelled, and they are usually translucent plastic. The outside of the reservoir should be marked with minimum and maximum lines for the coolant, and you can check here if you need to refill the coolant.
Refer to your owners manual if you are unsure about locating your coolant reservoir.
2. Mix the coolant and water
If the coolant is not already pre-mixed, use an empty container to mix equal parts coolant and distilled water to create the 50/50 coolant and water mix that’s usually recommended.
Longer life coolants are typically higher quality. Always use high-quality coolants for the best result for your engine.
3. Top off the radiator
If there is a cap on the radiator in your car and you can’t see the coolant level, top it off until you can see coolant at the bottom of the filler neck. There may also be a line indicating the maximum fill level.
4. Top off the coolant reservoir
If the coolant level is low in the reservoir, you can refill it to the max fill line but do not overfill it. The coolant mixture expands when it heats up and needs the extra room.
Keeping your coolant at the correct level is one of the ways to keep your radiator good working order.
What type of coolant do you need?
There are two major types of coolant: Type A and Type B. Type A contains anti-freeze and corrosion inhibitor, and Type B only contains corrosion inhibitor.
Mixing different coolant types can reduce the effectiveness of the corrosion inhibitor and damage your engine. If you are not sure which coolant type is already in your radiator, speak to an expert at Natrad for advice.
Do you have more questions about coolant? Read our FAQs here.
Things to remember
Refilling your coolant is a normal part of car maintenance. But if you find you have to top off your coolant frequently, this could indicate your car is leaking coolant. If this is the case, you need have a specialist at Natrad inspect your cooling system.
Along with refilling your coolant, you need to periodically flush and clean the system, and change the coolant entirely. This is more complicated and is usually best to have a Natrad radiator specialist do this for you.
For more information about radiator safety, repairs, or replacements, get in touch with us.
If your coolant level is too low (below or near the lower mark), top it up using a 50/50 mixture of water and antifreeze (for normal driving conditions), or pour pre-mixed antifreeze straight into the reservoir. You can use clean tap water in an emergency, but antifreeze should be added as soon as possible.Can you just top up radiator coolant? ›
If your coolant level is too low (below or near the lower mark), top it up using a 50/50 mixture of water and antifreeze (for normal driving conditions), or pour pre-mixed antifreeze straight into the reservoir. You can use clean tap water in an emergency, but antifreeze should be added as soon as possible.Can I just add coolant to my car? ›
If the coolant level is low in the reservoir, you can refill it to the max fill line but do not overfill it. The coolant mixture expands when it heats up and needs the extra room. Keeping your coolant at the correct level is one of the ways to keep your radiator good working order.Do you top up coolant in radiator or reservoir? ›
If the coolant level is low, add the correct coolant to the reservoir (not the radiator itself). You can use diluted coolant by itself or a 50/50 mixture of concentrated coolant and distilled water. When the coolant rises to the cold fill line, replace the cap and tighten it until you feel it click. Close the hood.Is antifreeze the same as coolant? ›
Well, antifreeze and engine coolant are similar, but not the same. Antifreeze is a concentrated, glycol-based liquid that must be diluted with water before use – at which point it is referred to as coolant. Alternatively, you can purchase pre-mixed engine coolant, a ready-to-use solution of antifreeze and water.How often should you top up coolant? ›
How regularly should you check your engine coolant? You need to check your engine coolant at least twice a year before summer and winter, ideally. Although, this advice may vary between car manufacturers. Coolant should be topped up whenever the level drops below the guide marks.Is it OK to top up coolant with water? ›
This is a frequently asked question, yes you can top up with just water, but you should only do this in an emergency to enable you to get to a garage. Engine coolant contains antifreeze, so diluting with water will lower the boiling point and the coolant will stop to work efficiently.How much coolant do I put in my radiator? ›
An average engine holds about 3 quarts (2 liters) of coolant, but this amount may vary depending on the vehicle's make, model, and type. For example, some Toyota models use only 1.5 quarts (1.5 liters), while others require 3 quarts (3 liters).Can a radiator run out of coolant? ›
How long can a car last without coolant? You won't get far without coolant. After a few miles, the engine will start overheating if so, and may automatically cut off to protect internal components from heat damage. If it doesn't have this safeguard, you risk serious engine damage if you continue driving.How do I know if I need to add coolant to my radiator? ›
Check your car coolant level regularly. Check it when the engine is cold. The coolant level has to be maintained at the "full" line on the overflow tank. If it's below that line, you need to add more coolant.
The coolant level should be near the top. If there is any "Full" marking etched into the radiator metal, that is the level to where your coolant should be.How long does coolant last in a car? ›
This deteriorated liquid can trigger severe harm to your engine by failing to control the temperature. Therefore, manufacturers suggest replacing the coolant periodically. It is recommended you change coolant after the first 210,000 km (140,000 miles) or 120 months, then every 30,000 km (20,000 miles) or 24 months.How much coolant do I add directly to my radiator? ›
Slowly fill the radiator or coolant tank with fresh coolant until the coolant is 1 in. below the neck of the radiator or a few inches below the full mark on the coolant tank. Start the engine and let it run. After the engine warms, you'll see the coolant level quickly drop in the radiator/coolant tank.How often should you top up radiator coolant? ›
How regularly should you check your engine coolant? You need to check your engine coolant at least twice a year before summer and winter, ideally. Although, this advice may vary between car manufacturers. Coolant should be topped up whenever the level drops below the guide marks.