Blog / Checking car fluids

Fluids & Filters · 5 min read

How to Check and Top Up Your Car's Fluids

A monthly fluid check takes about ten minutes and catches the majority of slow-developing problems before they turn into a breakdown or a much bigger repair bill.

Engine oil

Check with the engine cold, on level ground, using the dipstick. Amber and between the min and max marks is healthy. Black, gritty, or below the minimum mark needs attention.

Coolant

Check the level against the markings on the expansion tank, only when the engine is completely cold. Never remove the cap while hot.

Brake fluid

Check the level in the reservoir, usually near the back of the engine bay. A level that's dropped noticeably can indicate worn brake pads, since fluid moves within the system as pads wear, or it can indicate a leak, which is worth investigating rather than just topping up.

Power steering fluid

Not present at all on cars with electric power steering, which is now most new cars. If your car has a hydraulic system, check the reservoir level against its markings, usually visible without removing the cap.

Windscreen washer fluid

Simple to check and top up, but worth using a proper screenwash concentrate rather than plain water, especially in winter, since plain water can freeze in the lines and stop the system working entirely.

Automatic transmission fluid

Some automatic gearboxes have a dipstick for this, checked with the engine running and warm; others are sealed units not intended for owner checks at all. Worth confirming which type your car has before assuming you can check it yourself.

Building a simple monthly habit

Checking all of these together, alongside tyre pressure and tread, takes about the same time as a single stop for fuel, and catches problems while they're still cheap and easy to fix.