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How to top up your car fluids

How to top up your car fluids

Saffron Wilson

Saffron Wilson

  • 30 April, 2020
  • 6 min read

Checking the fluids under the bonnet and keeping them topped up is essential to keep your car running smoothly.

If you have your car serviced regularly or are on one of CarShop’s Service plans, then these fluids will be checked and topped up for you. A lot of modern cars have sensors that will alert you when something is low, but it is still essential you make regular checks as this will help you notice if something is amiss like a leak.

Don’t worry, you don’t need any fancy tools or expertise to do this, all you need is a few paper towels and 5 spare minutes.

Before you begin

Before you check your fluids, make sure your car is parked on level ground and ensure that the engine is cold and not running. We recommend at least 15 minutes after driving, but the longer the better.

Also, remember that all engines are different, so if you can’t see the reservoir straight away, check the owner’s manual.

Engine Oil

Engine oil is arguably one of the most important fluids in your car as it lubricates all of the engine’s moving parts. If engine oil runs low, wear on the engine can speed up, and if it‘s nearly empty, the lack of oil can cause the engine to seize up completely – and this damage can’t be fixed.

How to check oil level

Most engines have a dipstick that has level indictors on the tip.

All you need to do is pull the dipstick out and then wipe it with a cloth or paper towel. Afterwards, pop it back in and pull it back out - you’ll be able to see fresh oil residue on the stick.

If the oil on the dipstick is between the two level indicators, then your oil level is fine. But if it is below the lowest marker, then you’ll have to top up.

How to top up engine oil

First, place the dipstick back where it came from and ensure it is secure, then you can open the oil cap. This is normally a yellow cap and isn’t far from the dipstick.

Make sure you have the correct oil for your car, then pour some in –you can always use a funnel for this if you think you might spill.

Give it a little time to drain into your engine. If you check the dipstick too quickly it will still show the same level and you risk over filling. After a few moments, use the dipstick as before to check the level.

Don’t rush this, it’s better to put in oil little and often, as over-filling can cause leaks.


Coolant or antifreeze is essential as it stops the engine overheating. If this fluid gets too low, the engine could get too hot and cause serious damage.

How to check the coolant level

Most cars have a coolant reservoir that have minimum and maximum levels marked on the side, this means that you can simply have a look to see if it is between the ideal levels.

How to top up coolant

If the fluid is below or near the minimum mark, then you’ll need to top it up.

Quick tip – antifreeze tends to be concentrated and will have to be diluted by you, coolant is usually diluted and can be added straight to the engine.

For normal driving conditions, use a 50/50 mix of water and antifreeze, you can get this from the local supermarket so you won’t need to go out of your way. If you don’t have antifreeze and are desperate to top up, you can fill with tap water in the meantime, but ensure that the correct antifreeze concentration is added ASAP.

Be very careful when you handle antifreeze – it is poisonous. And as a side note, it can also damage your car’s paintwork, so try and avoid any spillages.

It’s worth nothing that in some cars, in particular those from the VW Group (Volkswagen, Seat, Skoda, Audi), need a specific type of coolant/antifreeze. Your vehicle handbook will state what type you’ll need and can often be a different colour (in the case of VAG cars, it is dyed purple). At the CarShop Service Centre we can identify any fluid visually and by the Autodata system, and can provide the correct coolant too!

Brake fluid

Before checking brake fluid, you will have to clean the top of the reservoir very carefully. Even a small amount of dirt falling into the brake fluid reservoir can risk the brakes functioning properly.

How to check brake fluid

On most modern cars, the brake reservoir has a screw cap. To check, all you need to do is unscrew it and have a look inside. Make sure that the level is within around half an inch from the cap.

It’s worth mentioning that you can’t leave the reservoir open too long, and the same goes for the container with the new fluid. This is because the fluid will absorb moisture from the air and can ultimately cause corrosion in the brake system.

How to top up brake fluid

If the fluid level is low, just top it up to within half an inch or so from the cap.

If the reservoir is empty, you’ll have to bleed the brakes. Since most modern cars have some sort of advanced braking system, then you will likely have to take it to a professional to get this done properly.

Your brake fluid should be replaced completely every two years, and can be done as part of a routine service.

Power steering fluid

If your car’s power steering is hydraulic, rather than electric, you’ll see a reservoir with a cap featuring an outline of a steering wheel on it.

How to check power steering fluid

Depending on the make of your car, the power steering fluid reservoir may have level markings similarly to the coolant, where you can visually to see if it is in the optimal level.

Otherwise, it will have a dipstick attached to the cap like the engine oil. If so, you treat it the same as if you would the oil. Wipe the dipstick and dip it back in the reservoir to check that the fluid is within the minimum and maximum levels.

How to top up power steering fluid

All you need to do is pour the fluid in until it is between the two levels. Again, particularly if you are using a dipstick, do this slowly and check often so you don’t accidentally overfill.

Clutch fluid

You only need to worry about this if you drive a manual car. If so, there will be a clutch fluid reservoir under the bonnet and will likely be near the brake fluid.

How to check the clutch fluid

The clutch fluid reservoir will usually have a minimum and maximum level marker, you can easily see whether the fluid is between these two points – if it is then great! You don’t need to do anything else.

How to top up clutch fluid

If the clutch fluid is below the bottom marker, then you will need to top up. Brake fluid can also be used as clutch fluid (most containers will read “brake & clutch fluid”). All you need to do is remove the cap and fill until the fluid sits between the two makers.

Windscreen wash

Although windscreen wash won’t affect the performance of your car compared to the rest of the fluids on this list, it’s still absolutely vital for your safety. Windscreen wash is essential to clean your windscreen and help you see clearly. And if that wasn’t enough to convince you, having an empty screen wash reservoir can be an MOT failure!

How to check screen wash

In most cars, you can’t actually see the screen wash reservoir level, only the cap for it. You will know it will need topping up if the nozzles don’t spray anything or if your car tells you.

How to top up screen wash

You can buy screen wash either as concentrated or ready mixed, and most supermarkets have them in stock.

If you want to use concentrated screen wash, then make sure you read the label. This will tell you how much to use during the year. In winter, you’re likely to need more concentrate to prevent freezing, as you should never use antifreeze here. Then you can mix the screen wash with tap water to dilute it.

NEVER USE WASHING UP LIQUID AS SCREEN WASH.  The salts in washing up liquid can damage your paintwork and will cost you to repair.

There’s no maximum level for screen wash like with vital fluids, so just pour until the bottle runs out or the screen wash reaches near the cap, whichever comes first.