Keeping your car’s fluids topped up is an important job. But it’s easy to forget. Your car uses six different fluids to run efficiently. Without them, your car won’t run effectively, and in some cases, low fluids can cause dangerous accidents. 

Checking your fluid levels also tells you about their levels and condition. Both are essential for preventing costly repairs and issues in the future. However, don't spend hours Googling “How to check clutch fluid or brake fluid levels.” Use our guide to get the lowdown in seconds. 

Scroll down to find out what each fluid does and how to check it. Time to give your car some TLC. Let’s go.  

Before the checks

Don’t rush into checking your fluid levels. Make sure your car is parked on a hard, level surface. Turn the engine off and allow it to cool before starting.  

You should also consult your owner’s manual for specific illustrations and instructions for your car. The manual usually includes: 

• Locations of reservoirs and fluid tanks 
• The proper conditions for checking your fluid levels 
• How to check the clutch fluid level (or whichever fluid you’re focusing on) 
• How to read reservoir fill lines and dipsticks  

Our guide applies to most vehicles. But it’s always good to double-check your car guidelines. 

1. Brake fluid

When pressure is applied to the brake pedal, the piston in the master cylinder causes the fluid to move through the pipes and act upon the cylinders in the brake callipers or drums, pushing the brake pads onto the discs and slowing the car.  

The system is sealed to use the incompressible property of brake fluid. Braking power reduces if any air gets into the lines. This can happen when the brake fluid runs low in the reservoir.   

Other causes of brake failure include old and degraded fluid and contamination, so it’s essential to check the level and change brake fluid when needed.

How to check your brake fluid

Locate the brake fluid reservoir. It's usually indicated by a yellow circle or octagon and will have 'Brakes' on the cap.

The fluid should be light brown and not overly dark or light. There should be no contaminants in the reservoir, such as leaves or dirt.

Wipe the cap clean before opening it to ensure nothing falls in.

Check the level on the side of the bottle, and fill it with the appropriate fluid to the line specified in the manual. 

Only use the recommended fluid type as stated in your owner's manual.   

2. Clutch fluid

In some manual cars, the clutch is operated by a cable. Check your owner’s manual to see if this is the case with yours. If so, you do not need to check your clutch fluid level.   

If your clutch is hydraulically operated, your car will either have a dedicated clutch fluid reservoir, or it may share this with the brake fluid reservoir.

How to check your clutch fluid

Look for a similar symbol to the brake reservoir, a circle within an octagon. The cap will say clutch or something similar.  

The level and colour considerations are the same as the brake fluid. It should be a golden colour without blemishes or dark spots.  

Look at the clutch fluid level. If closer to the "Minimum" line, it's time to refill.

3. Coolant

Another vital fluid to the engine's operation, the coolant travels through the engine and radiator, removing heat. Without adequate coolant flow, the engine would overheat very quickly, even with moderate usage.

Depending on the age of your car, the coolant can be in varying colours. With many different brands using differing colours, it's best to check the owner's manual to see what coolant is best for your car.

The coolant should be a fairly bright colour. It needs to be refreshed if it’s brown or clear. 

How to check your car’s coolant

WARNING: Never open the coolant reservoir when the engine is hot. The sudden release of pressure can cause severe burns.  

1. Locate the coolant reservoir. It's usually a black cap with yellow symbols, although Volkswagen vehicles tend to use bright blue caps. Make sure not to confuse the coolant with screen wash in this case.
2. Dilute the coolant to the recommended ratio stated on the bottle.
3. Pour until the level is somewhere between min and max.
4. Do not overfill. Too much coolant can cause high pressures to build up in the expansion tank and leak out.

4. Engine oil

An engine needs adequate lubrication to run, as oil coats all the surfaces in the engine and drastically reduces friction and thus reduces heat. If the engine oil is allowed to run out, terminal engine damage will occur.

Read more about when to change your engine oil in our blog.

Unlike the other fluids, the engine oil is not stored in a reservoir at the top of the engine bay. After the oil has cycled through the engine, providing lubrication, it drains back into the sump.

Engine oil should be checked regularly and inspected for colour and smell. Excessively dark oil can be a symptom of overheating. The oil should not smell of fuel in any way. This smell can indicate worn piston rings.

The engine must be off for at least 20 minutes before any checks. Ensure the car is on a level surface. 

How to check your engine oil level

• The sump or oil pan is a tray-shaped component that bolts to the bottom of the engine. It is where the oil is traditionally drained from, and the oil level is measured. Do this with the dipstick.
• To check your engine oil, locate the dipstick. It is usually fitted with a bright yellow or white handle. It will be either on the front or side of the engine, the latter for rear or some 4-wheel drive cars.
• Pull out the dipstick and wipe the oil off with a clean paper towel or cloth. Inspect the end to ensure the limit marks are present. The marks will be notches on the edge or plastic dipsticks, a patterned section.
• Re-insert the stick, ensuring it is firmly seated back in place. Remove carefully once again and check the level.   
• The filler oil cap is usually located on the top of the engine, marked "oil" or with a small oil can symbol. When you remove the oil cap, check for milky residue. This could be a symptom of head gasket failure and should not be ignored.
• The oil should ideally be in the middle of the two marks, but anywhere inside them is fine. If it's near the bottom or below, add a small amount of oil at a time. Re-check after 20 minutes or so.  

Note: Don't overfill the engine oil, as it may cause the excess to be forced out when the engine is running.  

5. Power steering fluid

Power steering is a luxury taken for granted in modern cars. If your car develops an issue with the PAS (power-assisted steering) system, you'll know about it!

The power steering will either be hydraulic or electrically operated. Check the recommended fluids section of your manual to work out which one your car is.

If hydraulic, the PAS uses a high-pressure pump and a hydraulic motor to actuate the steering rack. This makes the steering much easier for the driver.

How to check your power steering fluid

Locate the bottle. Often they say “Hydraulic Fluid”, “Power Steering”, or similar.

Remove the cap, being careful not to allow debris to fall in, and check the colour is bright and not darkening. There are two different types of power steering fluid, usually dependent on vehicle age. Your manual will advise which one to use.

Either use the level on the side of the bottle as before or check using the built-in dipstick, depending on the car. Refill until it’s in between min and max.  

6. Screenwash

The screenwash is a special detergent solution that keeps your car windows clean. The bottle will be inside the car’s bumper or front bodywork.

There will likely be a filler cap somewhere around the outsides of the engine compartment, with a long translucent tube disappearing into the car's structure.

Because the level is usually below this filler tube, the easiest way to check the level is to top it up. Use a high-quality screen wash, as cheaper ones can cause streaks and not properly clean the screen.

Can you use water instead of screenwash?

No, you can’t use water in place of screenwash. Screenwash (AKA window washer fluid) is a special fluid designed to remove grime and debris from your windshield. Water alone doesn’t remove oil or grease and may leave you with dirty windows.

Disclaimer

Now you’ve got the lowdown on how to check your car’s fluid levels, it’s time to get started! 

However, if you are unsure of any reservoir locations or fluid types required, consult your manual or a qualified person.  

Only attempt to fill the brake fluid if you are competent. Incorrect fluid usage could cause an accident or serious injury.  

It is critical to note a drastic reduction in brake fluid levels should not be ignored and could indicate a leaking pipe or component. If this is the case, inspect the car immediately to avoid a repair.

Car fluid level checklist

Be ready for any scenario. Here’s a quick checklist of equipment you’ll need: 

• Rubber or latex gloves
• Supplies of new fluids
• Protective glasses
• Funnels
• Fluid catch pans
• Clean rags/cloth

How to check the fluid levels in your car: The takeaway

All of these fluids are vital and should be both refilled and replaced regularly. Often forget to top up? Take note of your last fluid check to help yourself in the future. Or bookmark this blog so you don’t lose the content.  

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Author - Joseph Law

Joseph has been writing about cars for over seven years and writing for Bumper for over two, blending his passion for automobiles with a talent for storytelling.

Joseph has written about engineering and cars for Autozilla, Komaspec, and several engineering manufacturers. When he's not writing or tinkering with one of his five cars, Joseph dreams of owning an Alfa Romeo 33 Stradale.