Highline Car Care filling the antifreeze tank in Gilbert, AZ

How to Check Your Fluid Levels on Your Car

Checking your vehicle’s fluid levels is an important part of preventative maintenance. By regularly checking your car’s fluid levels, you can help to make sure everything continues to run smoothly, anticipating problems before they become too severe, and saving yourself time and money in the long run. Ultimately, effectively keeping tabs on your power steering fluid, transmission fluids, engine oil, coolant, brake fluid, and windshield washer fluid can ensure you get the absolute most from your vehicle.

What Is the Purpose of the Fluids in My Vehicle?

For many car owners, fluids are an afterthought. They may not spend much time considering them, or the important role they play in their vehicle. But fluids are essential for effective vehicle operation, playing essential roles in fuel economy.

Each type of fluid has its unique role to play — in short, they are as follows:

  • Engine oil lubricates the engine and keeps its operation smooth
  • Power steering fluid allows for smoother steering of your vehicle
  • Coolant helps to regulate engine temperature in both hot and cold weather
  • Brake fluid allows for smooth braking when pressurized, by forcing the brake pads to clamp down on the car’s rotors
  • Transmission fluids help to lubricate the gears, valves, and clutches, to keep everything operating smoothly
  • Windshield washer fluid is used to keep the windshield clear and easily visible for the driver

How To Check the 6 Essential Fluids In Your Car

Checking vehicle fluid levels is not especially difficult but takes a little bit of time. Before checking fluids, you should take a couple of preliminary steps.

First, consult your vehicle’s owner’s manual. This will have instructions on checking levels and will note particularities of where on your vehicle you should check levels. You will also want to ensure you are refilling any low fluids with the correct variety of fluid.

Second, set up an appropriate workspace. Ensure you are parked on level ground, with the emergency brake on. Assemble supplies, including necessary replacement fluids, funnels, catch pans, rags, gloves, and protective glasses.

Once you are all set up, here is how to check the necessary fluids in your vehicle.

Engine Oil

Engine oil plays an essential function in lubricating the movement of engine parts, which must spin thousands of times each minute. To check the engine oil, follow these steps:

  • Let the car cool down for at least ten minutes after driving, to allow engine oil to cool and settle
  • Remove the engine oil dipstick, clean it, and place it back in. Remove the oil dipstick a second time and confirm the reading. There should be “maximum” and “minimum” tabs on the dipstick, and you want the oil to be above the minimum, and ideally near the maximum.
  • If the oil is low, add more oil to your engine. You can confirm in the manual what type of oil is best to add.

Power Steering Fluid

It is vital to ensure power steering fluid levels are sufficient in your car. Power steering fluid allows for easy maneuverability, and driving can be much more difficult without it. You may notice your car’s turning is sluggish, which is a good indication to check the power steering fluid.

You will follow similar steps to check the fluid level. Depending on the type of engine, you may check the reservoir directly, or use a dipstick (as with engine oil).

  • (If filling a reservoir directly), identify the power steering fluid reservoir
  • Wipe it clean to identify the fluid level
  • If the level is low according to gauge, add more

Transmission Fluid

Transmission fluid keeps the transmission components — including gears, clutches, and valves — lubricated and sufficiently cool. Transmissions can be more complicated than other engine parts, and so you may benefit from a mechanic’s help. However, in some cars, you may be able to check it yourself with a dipstick, by following these steps:

  • Turn the car on, and place it in park or neutral
  • Check the fluid level, as you would with any other dipstick
  • Check the fluid condition; if it is unusually dark, milky, smells burnt, or has any material in it, it may need to be changed


Coolant keeps a busily running engine cool, helping to regulate its temperature in all seasons. Check the coolant level with these steps:

  • Let the engine cool, because hot coolant can cause burns
  • If your car has an expansion tank for coolant, check the level and make sure it falls in the appropriate spot
  • If your car does not, ensure the coolant radiator is filled to the top. If it is low, top it off with the same type of coolant.

Brake Fluid

Brake fluid is essential for the proper functioning of hydraulic brakes. To check the fluid, follow these steps:

  • Identify the brake fluid reservoir in the engine
  • Note if the fluid is at an appropriate level in the reservoir; add more if low
  • Ensure the fluid is not cloudy or dark, and replace it if it is

Windshield Washer Fluid

Windshield washer fluid is, in many ways, the easiest fluid to maintain, and it is vital to do so for good visibility. To check the level:

  • Open the reservoir, and fill it with windshield wiper fluid until nearly full; if the fluid is cloudy or looks abnormal, it should be replaced

When Is It Best To Check the Fluid Levels?

The answer to this question varies depending on the type of fluid. For best overall results, it is good to be in the regular habit of checking levels. A good way to do this is to check them when you change your oil, which should be 3000-5000 miles (longer if using synthetic oil). While some may need infrequent changes (or even no changes), it is a good habit to know where they are at.

Windshield washer fluid is an exception. Because it is so easy to fill, it is worth regularly checking when refueling your vehicle.

What Happens If I Run My Vehicle With Low Fluids?

Running your vehicle with low fluids can do significant damage to your engine and other vehicle components, worsen the wear and tear on your car, lower fuel economy, and be very dangerous. Each fluid plays a role; consequently, low levels are problems for unique reasons. Low engine oil or coolant can lead to engine overheating, while low transmission fluid can lead to transmission problems. Low brake fluid can make braking difficult or more dangerous, and low power steering fluid can make turning cumbersome and dangerous. Even low windshield wiper fluid can worsen visibility and present a hazard on the road.


In short, the best course of action is to ensure that the fluids on your vehicle are checked regularly and are in good condition. They each play an essential role, and your vehicle will be worth it without this simple, but essential, maintenance.

It is often worth consulting a mechanic to ensure your car is running smoothly, and to safely address any problems that arise. If you are looking for a great auto mechanic in Gilbert, Arizona, the East Valley, or nearby, contact Highline Car Care. We have a wealth of experience dealing with a variety of car problems, as well as performing preventative maintenance, and can ensure your car gets the treatment it deserves.

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