Your car’s fluids are like its lifeblood—without them, things can go south fast. From keeping your engine cool to ensuring your brakes respond in a split second, fluids play a critical role in your vehicle’s performance and safety. The good news? You don’t have to be a mechanic to keep tabs on them. With a few simple checks, you can catch issues early and keep your car running smoothly, mile after mile.
Why Fluid Checks Matter
Many vehicle fluids need attention more frequently than the typical 5,000- to 10,000-mile service intervals. Ignoring fluid levels can lead to poor performance, unexpected breakdowns, or even long-term engine damage.
Whether you’re prepping for a road trip or just want to protect your investment, regular fluid checks are a smart habit to adopt.
General Tips for Checking Fluids
Park on a level surface before checking any fluids.
- Never overfill—a little too much can be just as harmful as too little.
- Clean around caps and reservoirs before opening to avoid introducing dirt or debris.
- Always use the type of fluid recommended by your vehicle’s manufacturer (your owner’s manual will have the specs).
- If you find yourself topping off fluids frequently, it could be a sign of a leak or other issue—have it checked by a professional.
- Your owner’s manual is a good first step for knowing where the components are, and what to check.
Engine Oil
What it does: Lubricates engine parts, removes debris, and helps regulate heat.
When to check: Monthly. Change it every 3,000 to 5,000 miles, or according to your car’s recommendations.
How to check:
- Turn off the engine and let it cool.
- Open the hood and locate the oil dipstick (usually marked with a bright handle).
- Pull it out, wipe it clean, and reinsert it fully.
- Pull it out again and check the level. It should fall between the min and max markers.
- If low, add oil slowly and recheck. Usually, one quart is enough to go from the lower to the upper mark.
Check oil quality too:
Rub a little between your fingers. If it feels gritty, it may be breaking down. Look at the color—clean oil is amber or golden. Dark brown or black oil means it’s time for a change. Milky oil? That could indicate a coolant leak—get it checked ASAP.
Brake Fluid
What it does: Transfers force from your foot on the pedal to the brakes themselves.
When to check: Monthly. Replace every 1–2 years, or sooner if braking feels soft or delayed.
How to check:
- Locate the brake fluid reservoir, usually near the back of the engine bay.
- The fluid should be between the min and max lines.
- If it’s low, add the correct brake fluid for your vehicle.
- The fluid should be clear or light yellow. If it’s dark or cloudy, it needs to be replaced.
Note: Brake fluid absorbs moisture over time, which can lead to spongy brakes. Never ignore braking issues and know when you need new brakes.
Transmission Fluid (Automatic)
What it does: Lubricates transmission components and enables smooth gear shifts.
When to check: Monthly. Replace every 30,000 to 60,000 miles, or sooner if shifting feels rough.
How to check:
- Make sure the engine is running and warmed up.
- Engage the parking brake.
- Remove the transmission dipstick (if equipped), wipe it clean, then reinsert and remove it again to check the level.
- Fluid should be red, amber, or pink. If it’s brown, cloudy, smells burnt, or feels gritty, it’s time to change it.
- If low, add the appropriate fluid. Be cautious not to overfill.
Tip: Some newer cars have sealed transmissions. If you can’t find a dipstick, checking the fluid may require a mechanic.
Coolant (Antifreeze)
What it does: Regulates your engine’s temperature to prevent overheating and freezing.
When to check: At least twice a year. Full flush every 2–3 years (or longer, depending on the coolant type).
How to check:
- Only check when the engine is completely cool.
- Locate the coolant reservoir—usually a clear plastic tank with markings.
- Fluid should be between the min and max lines.
- If low, add a 50/50 mix of coolant and water unless your car specifies otherwise.
Warning: Be aware of the location of your radiator. Never open the radiator cap when the engine is hot—it can release scalding steam.
Power Steering Fluid
What it does: Makes steering smooth and responsive.
When to check: Monthly. Replace every 50,000 miles (varies by vehicle).
How to check:
- Turn off the engine.
- Locate the power steering fluid reservoir.
- Check that fluid is at the proper level (some caps have dipsticks).
- Some reservoirs have hot and cold markings—check according to your engine’s temperature.
Watch out for: Difficulty steering or a whining noise when turning could mean low fluid or a leak.
Windshield Washer Fluid
What it does: Keeps your windshield clean and ensures visibility.
When to check: Monthly—or more often in messy weather.
How to check:
- Open the cap to the washer fluid reservoir (usually marked with a windshield icon).
- If the level is low, top it off.
- In warm weather, use a bug-removing fluid. In winter, use a solution with antifreeze properties to prevent freezing.
When to Visit a Professional
While regular fluid checks can prevent many issues, some problems need a pro. Schedule a visit to your mechanic if you notice:
- Leaking fluids under your car—these often appear as puddles or drips.
- Dashboard warning lights—especially related to oil pressure, brakes, or coolant.
- Unusual noises—squealing, grinding, or whining sounds could point to fluid problems.
- Smoke from under the hood—could be due to leaking oil or overheating coolant.
And don’t forget, keeping your fluids in check is just one part of car maintenance. Protect your vehicle with the right insurance coverage to safeguard against the unexpected. Safe travels.
This article is furnished by California Casualty, providing auto and home insurance to educators, law enforcement officers, firefighters, and nurses. Get a quote at 1.866.704.8614 or www.calcas.com.
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