How to Change Engine Coolant in Your Car

how to replace your coolant

Although there are lots of quick fixes to cool your engine down, the only safe and long-term solution is to top up or replace your coolant. Coolant is an engine’s lifeblood; it helps keep the correct operating temperature, warms up the system quickly in cold weather and stops everything getting too hot when under stress. And if the temperature falls below freezing, coolant – mixed with a good antifreeze – also prevents internal damage, not to mention stopping corrosion from taking place within certain engine parts.

With that in mind, it’s worth thinking about how to check the coolant in your car, and if needed, how to change it. After all, there’s every chance you’ll need to replace it at some point in your driving life (and as quickly as possible!)


How to Check Your Coolant Levels 

It's important to understand how to check your coolant levels in order to avoid any nasty problems down the line. Your engine coolant should be checked twice a year, once before summer, and once before winter. It should also be checked immediately after the coolant pressure light comes on, when you should pull over, turn off your engine and (when the engine is cool) check the coolant overflow tank. This is next to the radiator and usually translucent, meaning you'll be able to see the level it's at by the markings.

If you do happen to find yourself in a (literally) sticky situation involving engine coolant, here’s everything you need to know about changing it up – without any major hassle. Or, if you're experiencing problems with your engine and you're not sure what it is, we can get this sorted for you.


Why Should You Change Your Engine Coolant?

Unsurprisingly, the effectiveness of the coolant fluid in your car’s engine deteriorates over time: the antifreeze chemicals lose their strength, especially if you top them up with water regularly. And in harsh winter weather, this can lead to the coolant freezing and expanding – which will damage the engine’s components.

For that reason, the cooling system should be drained, flushed and refilled every so often to replenish the antifreeze mixture and prevent rust and corrosion from forming. 


Changing Your Engine Coolant: A Step-by-Step Guide

When in doubt, read your vehicle’s handbook before you even start to change the engine coolant. As a rule of thumb, though, these simple steps will set you on the right track:

  1. Make sure the engine is cold, the handbrake applied, and that your vehicle is in first gear.
  2. Raise the front of your vehicle carefully on a jack.
  3. Put jack stands underneath and lower it into position, ensuring the back wheels have chocks in place.
  4. Remove any underbody shielding.
  5. Place a container beneath the radiator and undo the drain valve (see vehicle handbook for location).
  6. Flush the system as many times as necessary to ensure it is completely empty of coolant.
  7. Locate and remove the reserve tank from its holder and drain any remaining coolant, then put the tank back in place.
  8. Replace the drain valve.
  9. Refill the system to the base of the filler neck (with the correct antifreeze!).
  10. The following instructions for bleeding/topping up procedures may also apply: run the engine briefly, then top up the coolant; replace the radiator cap, then run the engine again until the cooling fan turns on, before checking levels and topping up as required.


How to Change Your Coolant

Time Period

It shouldn’t take longer than two hours to refresh and replace the engine coolant in your car.

Parts and Equipment You May Need

Here are some useful tools to help you stay safe and get the best results while changing engine coolant:

·       Gloves and protective eyewear, because it’s dangerous to freely handle auto-related chemicals.

·       A pan or bucket to collect any excess water.

·       A floor jack (if necessary). 

·       Axle stands to support your car while working with the coolant system.  

·       A socket and ratchet spanner set – just the ticket for dismantling an engine.  

·       A screwdriver for accessing the actual engine components.  

·       Rags to help clean up easier.  

·       Pliers, for when you need a tight grip on your engine’s internals.  

·       New coolant – to top up.  

·       Replacement hoses (if you find your current ones to be faulty).  


Why Does the Colour of Engine Coolant Matter?

Colour is a good indication of your engine coolant’s condition. The coolant should be the same colour as when you first put it in; any change towards a rusty, reddish-brown hue signals replacement.

We advise you to check the level and colour of your car’s engine coolant periodically – at least once a week – so that any problems can be dealt with before they get out of hand.


A Guide to Changing Your Coolant

If you’d like a visual overview of this whole process, give our instructional video a watch below.


Remember, the recommended engine coolant change intervals vary widely from vehicle to vehicle, so make sure you check the maintenance schedule in your owner’s manual. Of course, if you’re after professional assistance when it comes to replacing your engine coolant, you can always contact MotorEasy to book a service - where your car's engine coolant levels will be checked, as well as other essential elements.


Book a service


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