How to check the 5 essential fluids in your car

One of the simplest and most important things you can do for the longevity of your vehicle is to make sure that the fluids are maintained at the right level and in good condition. Performing scheduled maintenance is aimed at improving the condition of the fluids, but it is also important that the fluids remain at the correct level between these services.

Here is a summary of the five most important fluids found in most vehicles and how to check the level.

1. Engine oil

Description: All internal combustion engines require engine oil to lubricate many moving internal parts. Without oil, these parts would overheat and could completely jam.

Precautionary measures: Motor oil is a potential carcinogen, so be sure to wear gloves if you have them and wash your hands thoroughly after handling motor oil.

Risks associated with low fluid levels: If the oil level drops below the minimum operating range level, engine performance may be adversely affected, including the possibility of complete engine failure.

How to check the level: Most vehicles have an oil dipstick with maximum and minimum marks to check the oil level. Pull out the dipstick completely and wipe the bottom of the dipstick with a dry cloth. Then, fully insert the dipstick again and remove it again, this time holding it in a vertical or horizontal position to prevent oil from rising up the dipstick causing an inaccurate reading. Where the dipstick is now covered with oil is the level; ideally somewhere between the maximum and minimum marks.

2. Engine coolant

Description: Heat is a normal by-product of the operation of an internal combustion engine. The engine coolant absorbs this heat and dissipates it through the radiator, allowing the engine to maintain its set operating temperature.

Precautionary measures: Engine coolant can be quite hot and under high pressure. This can make opening the system very dangerous. If you need to open the system, be careful to only do it on a cold engine and do it very slowly or you risk serious burns.

Risks associated with low fluid levels: A low coolant level can cause the engine to overheat, which can cause serious damage.

How to check the level: The best way to check the coolant is after the car has been sitting for a few hours, usually before starting after an overnight stay. Some vehicles allow you to check the level by simply looking through the translucent coolant expansion tank or overflow tank and making sure the level is between the minimum and maximum marks. Others require you to open the radiator or pressurized expansion tank (common in German cars) to check the level.

3. Brake fluid

Description: When you depress the brake pedal, the master cylinder (which is attached to the brake pedal) moves brake fluid through the brake lines to the brake calipers or wheel cylinders, where it is used to apply the brakes.

Precautionary measures: Brake fluid is hygroscopic, meaning it absorbs moisture from the environment. Keep all brake fluid containers and reservoirs tightly closed until you need to add fluid, and then immediately close them again after adding fluid. Brake fluid is also extremely damaging to paint, so if you spill it, be sure to wash the area thoroughly with soap and water right away.

Risks associated with low fluid levels: If there is too little brake fluid, you may experience loss of brake pressure or even total brake failure.

How to check the level: Most modern cars use a translucent plastic reservoir that allows you to check the fluid level without opening the system. As with other fluids, you simply watch the fluid level through the reservoir; make sure the fluid level is between the minimum and maximum marks.

4. Power steering fluid

Description: Many manufacturers are now equipping vehicles with more efficient electric power steering systems that reduce engine parasitic drag, resulting in better fuel economy. Despite this, there are still many vehicles using the old hydraulic power steering systems. These systems use pressurized power steering fluid to help you turn the steering wheel.

Precautionary measures: Power steering fluids vary by manufacturer, and some are potential carcinogens. Just in case, I suggest wearing gloves and washing your hands thoroughly after handling the liquid.

Risks associated with low fluid levels: A low fluid level can cause loss of steering control or total failure of the power steering system, which could lead to an accident.

How to check the level: Many power steering reservoir caps have a built-in dipstick or use a translucent reservoir that allows you to see the fluid level from the outside. The process is similar to checking engine oil: remove the dipstick, wipe it clean, then reinsert and remove again. The level must be between the minimum and maximum marks. If it's the translucent tank type, just look through it to make sure the liquid level is between the marks.

5. Windshield washer fluid

Description: Windshield washer fluid does exactly what the name suggests - it cleans your car's windshield.

Precautionary measures: Washer fluid is fairly harmless, although depending on the alcohol and detergent content, it can irritate the skin. If you get on your skin, you can simply wash it off with soap and water.

Risks associated with low fluid levels: The only risk of low washer fluid is that you may run out of fluid and not be able to clear your windshield when you need to, which can limit your visibility while driving.

How to check the level: The best part here is that you don't actually need to check the level. Most cars don't even have a way to check the level. Instead, if you run out of fluid or think you're running low on fluid, you can simply fill the reservoir all the way to the top at any time - there's no risk of overfilling. Some vehicles have a built-in level sensor that alerts you when the level is low.

Friendly Disclaimer

This list is not exhaustive and does not refer to a specific vehicle. This is a general guide to the most important fluids in most vehicles on the road. If you're having trouble finding any of the fluids listed above, your vehicle owner's manual will usually have a diagram specific to your model.

All of these checks should be performed with the vehicle stationary, on a level surface, and with the engine off. If any of the fluids are found to be low, it is highly recommended that they be topped up with the correct fluid (such as the correct weight of oil, not just any oil you have) and have the vehicle checked by a certified technician. mechanic, for example, from AutoCar, to diagnose why the fluid level was low.