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Summary: In this guide you will learn how to identify your engines radiator and/or top pot and check your fluid levels.
How to check radiator fluid levels
Please note that this is only a general guide and is not specific to any one make or model of vehicle. For more detailed information on your own particular car, please consult a workshop manual specific to your own make and model!
Please read this first
If you have recently driven your vehicle, please leave it for at least an hour for the engine and other components to cool down. If you do not you may risk injury!
Required Tools:
1. An old rag
2. An old soft-drinks bottle (preferably 2ltr and with a screw cap. Only if you need to top up your levels)
3. A new container of engine coolant/antifreeze (only if you need to top up your levels)
4. A litre of water (only if you need to top up your levels)
Step 1 – Open the bonnet
Open the bonnet of your vehicle via the release catch normally located just under the dash board on either the driver or passenger’s side, walk to the front of the car and slide your hand under the bonnet and squeeze the latch. When the latch releases, prop the bonnet up using the provided support.
NOTE: As the fluid in your cars water system expands when hot and contracts when cold it is a good idea to check your levels when the engine is slightly warm. Start the car and let it run until the temperature gauge on the dash signals normal operating temperature, turn it off and leave it for about 40 - 50 minutes to cool and now you are ready. REMEMBER: Some components hold heat longer than others. Always be careful!
You may also want to move your car onto a flat and level surface, if it isn't already in order to get an accurate fluid level reading. You can do this whilst warming up the engine.
Step 2 – Locate the radiator and expansion chamber
In order to check your levels you first have to locate the radiator and the expansion chamber. The radiator will be located right at the front of the engine bay (the front of the car, unless you have a Mini in which case it is located to the right side of the engine bay).
Now that you have found the radiator, depending on the make and model of your car, you may also have an expansion chamber. This will appear as a white or clear plastic bottle and can normally be found near the radiator or towards the top right hand side of the engine bay. Again, this may depend on the make and model of your car.
The main purpose of the expansion tank is to act as an overflow. As I have said, as the fluid within an engine heats up it expands and the job of the expansion tank is to catch the resultant over flow. This is rather important as if it didn't have any where to go it would pressurise and eventually explode!
NOTE: Some older cars may not feature and expansion tank and will only use a radiator.
Step 3 – Check the fluid levels
Now that you are familiar with the location of the two components (the radiator and expansion tank) you can now check the levels.
On the very top of the radiator there should be a cap (again, this may depend on the make and model of your car as some do not allow acces directly into the radiator. Instead you will have check the levels via the expansion tank). NOTE: Do not take the cap straight off the radiator as the fluid in the system may still be pressurized and will explode in your face! To get around this issue take your old rag and place it over the cap. Now, grip the rag and the cap in your hand and apply a little down-ward pressure and twist the cap to open (anti-clockwise). You may hear a slight hiss. This is just the system de-pressurizing. When this has finished take the cap off, being careful as the fluid could still come rushing out.
With the cap removed, peer down into the radiator and you should see the fluid. If you can't and the top of the inside of the radiator appears dry then you will need some fluid.
If you can see plenty of fluid then your levels are fine, but it is also worth checking the expansion chamber.
On the side of the expansion chamber you should be able to see 2 markers. They may appear as either 2 lines, one above the other or the abreviations MIN and MAX. Ideally, the fluid level should be just under the MAX marker. If it is then your levels are fine. If the level is sitting below the half way point, or lower, between the two markers then you will need some fluid.
If your levels are fine, procede to step 5
Step 4 – Topping up fluid levels
If you have found that any of your fluid levels are low then you must top them up. If you don't then your engine may overheat and this could lead to thousands of pounds in garage expenses.
When topping up your levels you should use roughly a 50/50 mix (50% water 50% coolant/antifreeze). Take your soft-drinks bottle and fill half way with water. Now top up the rest with coolant/antifreeze, screw the cap on and give it a shake to mix it up (you can buy pre-mixed water/coolant. It is up to you which method you choose).
To top up your fluid level simply remove the cap on the expansion chamber and fill to just below the MAX marker or top line (depending on how yours is labeled) and replace the cap, scewing it down firmly.
If your vehicle does not have an expansion chamber, then you will have to top up the fluid level via the cap on the top of the radiator. For this simply remove the cap (remember to do this slowly and with a rag) and steadily pour your water, coolant/antifreeze mixture in until the level reaches the top of the flat surface (the radiator core) you can see when looking down into the radiator. Fill just beyond this level, just to the base of the neck (the part that the cap screws down onto)
Step 5 – Testing
With your coolant levels now checked and adjusted if necessary clear away all unnecessary objects such as tools etc.... from the engine bay. Before you close the bonnet just check over the caps once more (radiator/expansion chamber) to make sure that they are on firmly and will not come off during driving. Now, start the engine and let it run for a few minutes and then turn it off. Listen around the engine area for anything that sounds like a "gurgling". If you can hear this then some air may have gotten into the water system and this will cause "air locks". This could potentially be a serious problem as the air will prevent the fluid from circulating the engine correctly and eventually cause it to overheat. If you are experiencing a problem such as this then have your vehicle checked out by a mechanic.
NOTE: If your vehicle is experiencing rapid water loss then you may have a leak. This needs to be sorted as soon as possible as your engine will overheat and cause serious and very expensive damage if not corrected. Seek consultaion from a qualified mechanic.
You have now successfully completed this project.
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