Car fluids are the hidden heroes that keep our vehicles “well-oiled machines.” Without fluids like engine oil and brake fluid, our cars wouldn’t just be uncomfortable to drive – they’d be unsafe too!
For this reason, it’s essential that you know about the 6 common fluids to check in a car, how to do it, and why they are so crucial to your comfort and safety. We’ll also cover some important FAQs, like how to tell fluid leaks apart.
This Article Contains
- What Is the Purpose of Fluids in My Car?
- 6 Common Fluids to Check in Car (+ How to Do It)
- 3 FAQS about Car Fluids
Let’s get started.
What Is the Purpose of Fluids in My Car?
Each vital fluid in your car plays a role in maintaining the functionality and longevity of the moving parts in your vehicle’s most essential components. Some fluids work to improve your car’s performance, while others focus mainly on enhancing vehicle safety while driving.
Without functional fluids in your car, it won’t take long to notice your daily drives becoming less comfortable and far more dangerous.
Let’s dive deeper into the six common fluids in a car and how to check them.
6 Common Fluids to Check in a Car (+ How to Do It)
These six fluids are the most likely to require regular maintenance and monitoring between major services:
1. Engine Oil
Engine oil (aka motor oil) is a vital fluid with one main job — lubricating engine parts. This is a crucial element in your car’s general upkeep, as engine components are prone to creating friction, resulting in overall engine wear.
Note: Conventional engine oil is different from synthetic oil. Both older and newer cars can use synthetic oil and require less frequent oil changes and top-ups.
Symptoms of low engine oil:
- Illuminated oil pressure warning light
- Burning oil smell
- Strange noises
- Weaker engine performance
- Overheating engine
How to check engine oil:
Checking your motor oil is a simple procedure. Locate the engine oil dipstick — a red, yellow, or black handle on the side of your engine.
Once you’ve found the engine oil dipstick, remove it, wipe the existing oil off, and reinsert it.
You’ll then want to remove it a second time and inspect it. Your engine oil level should be near the maximum line and yellow/amber in color when new or black/brown when old.
If you notice black or brown engine oil, it’s time for an oil change.
2. Brake Fluid
Arguably the most important fluid, brake fluid adds the “hydro” to “hydraulic pressure.” Pressing the brake pedal creates pressure in the brake line forcing brake fluid into the caliper — engaging the brake pad against the rotor brakes.
When your brake fluid level is low, you’ll get reduced pressure when pushing the brake pedal.
The outcome?
Your brakes will lose efficiency!
Not ensuring your brake fluid level and pressure is up to par is a one-way ticket to putting yourself and others in danger when driving.
Symptoms of low brake fluid:
- Illuminated brake warning light on your dash
- Brake fluid level appears low, or the fluid is discolored or dirty
- Brake pedal feels spongy or mushy
- Your vehicle has a longer stopping time than usual
How to check brake fluid:
Locate the brake fluid cap under your car’s hood and visually inspect the brake fluid reservoir for fluid volume and color. The fluid should be near the top of the brake fluid reservoir and a white wine/amber color.
If either of these is off, you must either check for brake line leaks or change your brake fluid.
3. Automatic Transmission Fluid
Considered a “VIP” car fluid, automatic transmission fluid (sometimes called transmission oil) lubricates and cools down the essential components of the transmission, like gears, clutches, and valves.
In new cars with an automatic transmission, it also helps to create hydraulic pressure. When driving with a low transmission fluid level, the transmission is prone to stiff shifting, surging, and seizing.
Symptoms of low automatic transmission fluid:
- Unusual noises
- Burning smell
- Transmission leaks
- Slipping gears
- Slow gear engagement
- Poor vehicle acceleration
How to check automatic transmission fluid:
Some new cars come with a transmission fluid dipstick, but others require a mechanic to inspect.
If your vehicle has an automatic transmission dipstick, checking your fluid is similar to checking engine oil, with two differences:
- The engine must be running
- The transmission must be in neutral or park (depending on the manufacturer)
The fluid should be an amber/red color. Any darker or discolored, and it’ll need replacing.
4. Power Steering Fluid
Power steering fluid is a hydraulic fluid used within the steering system that acts as a bridge between the steering wheel and your car’s wheels.
It reduces the effort needed to turn the wheels and lubricates moving parts inside the steering system. While newer cars are less prone to power steering fluid leaks, if you have an older car, there’s a chance it doesn’t have power steering at all.
Symptoms of low power steering fluid:
- Difficulty turning the steering wheel
- Loud steering
- Red or pink stains under the vehicle
How to check power steering fluid:
Locate a reservoir cap or dipstick underneath the hood of your car labeled “power steering.” Inspecting the fluid level and quality is similar to checking engine oil. Power steering fluid should be pinkish in color.
5. Radiator Fluid (Coolant or Antifreeze)
Coolant is an important fluid for three reasons — it reduces engine rust and corrosion, reduces engine pressure, and prevents freezing. Coolant doesn’t freeze or expand in cold temperatures like water. This ultimately shields your engine from cracking beneath increased pressure.
Symptoms of low coolant level:
- High engine temperature
- A/C malfunctioning
- A sweet smell in your air conditioning or under the hood
How to check coolant:
Locate the radiator cap labeled “radiator fluid” or “antifreeze” on the top of your radiator. When removed, the proper level for radiator fluid should be near the top of the reservoir.
Never remove the radiator cap when the engine is hot, as the pressure may spray out hot fluid, causing burns.
The color of your radiator fluid will vary based on the manufacturer and model of your car. It’s usually green, blue, yellow, purple, or pink — just make sure not to mix different brands!
6. Windshield Washer Fluid
Windshield washer fluid is a cleaning mixture that removes debris and marks from the windshield when the wipers are engaged. It helps improve safety by ensuring there’s no obstruction to the driver’s field of view.
Symptoms of low windshield washer fluid:
- Illuminated windshield warning light
- No fluid expells when wipers are engaged
How to check windshield wiper fluid:
Open the hood of your car and locate the washer fluid reservoir. Remove the cap and visually inspect the fluid level (which should be near the top). Windshield wiper fluid is usually white or blue, but the color may vary on the manufacturer.
Note: If your vehicle has a rear wiper, there may also be a second reservoir for it. Locate it and repeat the steps above.
Now that we’ve covered the common fluids you should check in your car, let’s review a few common questions about car fluids.
3 FAQS about Car Fluids
Here are the answers to important car fluid questions you should know about:
1. What Happens If I Drive With Low Car Fluid Levels?
Driving with low (or no) car fluids can put you, your passengers, and other drivers in grave danger and should be avoided at all costs.
Driving without your cars fluids might cause components like the engine and transmission to seize while driving or cause brakes and power steering to fail — all of which would be catastrophic when on the road.
The moral?
Make time to check in on your car fluids regularly, and never skip a major service. Luckily, newer vehicles come equipped with an arsenal of gauges to monitor fluid levels.
2. How Often Should I Change My Car Fluids?
The recommended time to service your cars fluids varies by fluid type.
Here’s a rough guideline you can follow:
- Automatic transmission fluid can typically go 100,000-150,000 miles before needing a change.
- Engine oil can usually go 5,000-10,000 miles between changes, with some manufacturers recommending up to 15,000 miles.
- Power steering fluid is not typically listed for replacement unless it becomes contaminated or there’s a suspected issue.
- Radiator fluid should be changed every 2-3 years or when there’s a noticeably low coolant level from a leak.
- Windshield washer fluid should be refilled during every service interval, at a change of seasons, or whenever it runs out.
- Brake fluid should be changed at least every two years at the minimum.
3. What Should I Do If I Notice a Fluid Leak or Loss of Fluid in My Car?
Before resolving fluid leaks from your car, you first need to be able to tell the fluids apart.
Here’s a quick breakdown of how to do so:
- Engine oil: Leaks from under the engine bay and will be brown or black.
- Engine coolant: Leaks from under the engine bay and is usually green or red, with a thin consistency. Be aware that engine coolant is toxic for humans and animals, so handle it cautiously.
- Automatic transmission fluid: Leaks under the car’s center, is reddish in color, and smells similar to gasoline.
- Power steering system fluid: Leaks from under the hood of your car and is slick like engine oil but slightly thinner. The color is typically red.
- Brake fluid: Found under any area of your vehicle and looks similar to power steering fluid — contact a mechanic for this one.
- Windshield wiper fluid: Leaks from under the front of your vehicle, has the consistency of water, and is often brightly colored.
When you have identified the type of fluid leaking from your car, you can give a professional mechanic detailed information to help them repair your vehicle efficiently.
Final Thoughts
Car fluids are the lifeblood of your vehicle. Without them or with low fluid levels, don’t expect to go anywhere without a struggle! Checking your car fluids regularly and getting regular service inspections is the best way to maintain your vehicle and prevent car fluid leaks.
But what do you do when you experience a car fluid leak?
Contact a reliable auto mechanic like AutoNation Mobile Service!
AutoNation Mobile Service is a convenient mobile vehicle auto repair and maintenance solution with expert mechanics. We‘ll give you competitive upfront pricing plus a 12-month warranty on all repairs!