How to check your car's fluid levels at home
A 10-minute guide to inspecting engine oil, coolant, brake fluid, power steering and screen wash. Catch small problems before they cost you hundreds.
Checking your car’s essential fluid levels can help prevent overheating, poor braking, engine wear and unexpected breakdowns. Basic checks are often simple, but always follow the vehicle handbook and work safely.
At HON CAR SERVICE, we encourage drivers to carry out basic checks while arranging professional maintenance when required.
Why checking your car’s fluids matters
- Low coolant can contribute to engine overheating.
- Low engine oil can increase engine wear.
- Low brake fluid may indicate worn components or a leak.
- Low screenwash can reduce visibility during rain and spray.
- Repeated fluid loss may indicate an underlying fault.
1. Engine oil
How to check the oil
- Park on level ground and switch off the engine.
- Allow the engine to cool and the oil to settle.
- Locate and remove the dipstick.
- Wipe it clean, reinsert it fully and remove it again.
- Check that the level is between the minimum and maximum marks.
Use only the oil specification recommended for your vehicle. Add oil gradually and never overfill. Repeatedly low oil levels or visible leaks require professional investigation.
2. Coolant and antifreeze
Only check the coolant reservoir when the engine is completely cool. The level should normally sit between the minimum and maximum marks.
Never remove a coolant cap while the engine is hot. Pressurised coolant can cause serious burns. Low coolant may indicate a leak or another cooling-system fault.
3. Brake fluid
The brake-fluid reservoir is usually located near the rear of the engine bay. Check that the level is between the markings and use only the correct fluid specification.
Low brake fluid can be associated with worn brake components or a leak. If the brake pedal feels soft, braking performance changes or fluid is leaking, do not continue driving unnecessarily—arrange urgent professional advice.
4. Transmission fluid
Some automatic vehicles have a transmission-fluid dipstick, but many modern cars require a specific procedure or professional equipment. Always follow the owner’s handbook.
Slipping gears, delayed engagement, difficulty changing gear or unusual transmission noises should be inspected.
5. Power-steering fluid
If your vehicle uses hydraulic power steering, check the reservoir markings and use only the specified fluid. Some modern vehicles use electric power steering and will not have a fluid reservoir.
Heavy, stiff or noisy steering should be checked rather than treated by adding fluid alone.
6. Windscreen washer fluid
Locate the reservoir marked with a washer symbol and top it up with suitable screenwash. Check that the jets spray correctly and the wipers clear the glass.
An empty reservoir or non-working washer system may contribute to an MOT problem.
When should you ask a mechanic for help?
- A fluid level repeatedly drops.
- You see a coloured or oily leak beneath the car.
- A dashboard warning light appears.
- The engine overheats or smells unusual.
- The brake pedal feels soft.
- Steering, gear changing or handling changes.
- You are unsure which fluid to use.
Do not mix fluids unless the vehicle manufacturer specifically permits it. If you are unsure, leave the system closed and arrange professional advice.
Frequently asked questions
Should I check fluids when the engine is hot?
Some fluids must only be checked when the engine is cool. Always follow the handbook, especially for coolant and pressurised systems.
Can I use water instead of coolant?
Use the coolant mixture recommended for your vehicle. Water alone may not provide the required corrosion and temperature protection.
Why is my brake fluid level low?
Possible causes include brake-pad wear, a leak or another braking-system issue. Repeated low levels need professional diagnosis.
How often should I check my fluids?
Check them according to the vehicle handbook and before long journeys. Check sooner if you notice warning lights, leaks or changes in performance.
Book a professional fluid inspection
HON CAR SERVICE can help arrange fluid checks, servicing, diagnostics, MOT testing and repairs for many makes and models. Visit our service options or start an online quote using your registration and postcode.