How to Check and Top Up Car Fluids: A Simple UK Guide

Summary

• Five key fluids: Your car needs engine oil, coolant, brake fluid, power steering fluid, and washer fluid to run safely.
• Check monthly: A quick 10-minute check once a month can prevent breakdowns and expensive repairs.
• Easy to do yourself: You don't need any special tools. Our maintenance checklist covers the basics.

Your car runs on more than just fuel. It needs five key fluids to work safely and smoothly.

Let them run low, and you could face a breakdown. Or worse, serious engine damage that costs thousands to fix.

The good news? Checking your fluids takes about 10 minutes. You can do it yourself with no special tools. Here's how.

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Before You Start

Park on a flat, level surface. Wait for the engine to cool down if you've been driving. Hot fluids can burn you.

Open the bonnet. Most cars have a release lever under the dashboard on the driver's side. Pull it, then lift the bonnet and prop it open.

Keep a clean cloth or paper towels handy. You'll need them for the dipstick.

Safety first: Never open the coolant cap when the engine is hot. The pressure inside can cause boiling liquid to spray out.

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1. Engine Oil

Engine oil keeps all the moving parts in your engine running smoothly. Without it, your engine would seize up fast.

How to check

1. Find the dipstick. It usually has a yellow or orange loop handle.
2. Pull it out and wipe it clean with a cloth.
3. Push it all the way back in.
4. Pull it out again and look at the oil level.
5. The oil should be between the minimum and maximum marks.

How to top up

If the oil is below the minimum mark, you need to add some. Find the oil filler cap on top of the engine. It usually has an oil can symbol on it.

Add a small amount at a time. Wait a minute, then check the dipstick again. Don't overfill it.

Use the right type of oil for your car. Check your owner's manual or ask at a parts shop.

What colour should oil be? Clean oil is golden. Dark brown or black oil means it's old and due for a change. Read our car servicing guide for when to change it.

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2. Coolant (Antifreeze)

Coolant stops your engine from overheating in summer and freezing in winter. It's a mix of antifreeze and water.

How to check

1. Find the coolant reservoir. It's a clear plastic tank, usually near the radiator.
2. Look at the side of the tank. You'll see minimum and maximum level marks.
3. The coolant should sit between these two marks.

How to top up

Only open the cap when the engine is cold. Add a 50/50 mix of antifreeze and water. Never use just plain water.

If your coolant drops quickly, you might have a leak. Get it checked by a mechanic. Our radiator coolant guide has more details.

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3. Brake Fluid

Brake fluid makes your brakes work. When you press the pedal, this fluid pushes the brake pads against the discs to slow you down.

How to check

1. Find the brake fluid reservoir. It's a small, clear container near the back of the engine bay on the driver's side.
2. Check the fluid level against the minimum and maximum marks on the side.

How to top up

Use the correct type of brake fluid. Your manual will tell you which one (DOT 3, DOT 4, or DOT 5.1).

Be very careful with brake fluid. It can damage paintwork if spilled. Wipe up any drips straight away.

Warning: If your brake fluid drops a lot between checks, it could mean your brake pads are worn or there's a leak. See a mechanic. Read our car brakes guide for more.

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4. Power Steering Fluid

This fluid makes your steering wheel easy to turn. Without it, steering becomes very heavy and hard.

Not all cars have power steering fluid. Some modern cars use electric power steering instead. Check your manual to see which yours has.

How to check

1. Find the power steering reservoir. It's usually a small tank with a cap near the front of the engine.
2. Some have a dipstick built into the cap. Others have marks on the side.
3. Check the level is between minimum and maximum.

How to top up

Use the correct fluid type for your car. Add small amounts until it reaches the right level.

If you hear whining or groaning when you turn the wheel, it could mean low fluid. Get it checked.

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5. Washer Fluid

This is the easiest one. Washer fluid keeps your windscreen clean. Without it, you can't see properly in rain or spray.

An empty washer bottle will also fail your MOT. So keep it topped up.

How to top up

1. Find the washer fluid reservoir. It has a windscreen wiper symbol on the cap.
2. Open the cap and fill with a mix of screenwash and water.
3. In winter, use a stronger mix of screenwash to stop it freezing.

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Quick Reference Table

Fluid	Where to Find It	How Often to Check	What Happens If Low
Engine oil	Dipstick (yellow/orange handle)	Monthly or before long trips	Engine damage
Coolant	Clear tank near radiator	Monthly	Overheating
Brake fluid	Small tank, driver's side	Monthly	Brake failure
Power steering	Small tank near front	Monthly	Heavy steering
Washer fluid	Tank with wiper symbol	Weekly in winter	MOT fail, poor visibility

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When to See a Mechanic

Topping up fluids is normal. But if any fluid drops quickly, that's a sign of a problem.

See a mechanic if:

• You need to top up the same fluid every week.
• You spot puddles under your car.
• Your dashboard warning lights come on for oil, temperature, or brakes.
• Your brakes feel soft or spongy.
• Your engine runs hot or the temperature gauge rises.

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Checking your car's fluids is one of the simplest things you can do to keep it running well. Spend 10 minutes a month and you'll avoid costly repairs and unexpected breakdowns.

Want to learn more about looking after your car? Read our complete essential car maintenance checklist.

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