How to Check Your Car's Fluids and Tire Pressure

What you need to check and how often

Your car needs five regular fluid checks: engine oil, coolant, brake fluid, power steering fluid, and windshield washer fluid. Tire pressure should be checked at least once a month and before long trips. Most of these take under ten minutes and require no special tools beyond what you probably have in your garage.

Engine oil is the most critical — it lubricates your engine and breaks down over time. Check it every month or before a long drive. Coolant keeps your engine from overheating; check it when the engine is cold, never when hot. Brake fluid, power steering fluid, and washer fluid need less frequent attention but should still be part of your monthly routine. Tire pressure changes with temperature, so check it when tires are cold — first thing in the morning or at least three hours after driving.

Key Takeaways

• Engine oil, coolant, brake fluid, power steering fluid, and windshield washer fluid should all be checked monthly, with oil being the most important.
• Check tire pressure when tires are cold, using the pressure listed on the driver's door jamb or your owner's manual, not the number on the tire sidewall.
• You need only a dipstick (usually in the car), a tire pressure gauge (under $15), and a flashlight to check all fluids yourself.
• Low fluid levels or incorrect tire pressure can damage your engine, reduce fuel economy, and make your car unsafe to drive.
• Most fluid reservoirs are clearly labeled under the hood, and your owner's manual shows exactly where each one sits.

How to check engine oil

Open your hood and locate the dipstick — it usually has a yellow or orange handle and sits on the right or left side of the engine. Pull it straight out and wipe it clean with a paper towel or rag. Reinsert it fully, then pull it out again. The oil should reach the "full" mark on the stick; if it is below the "low" or "add" mark, you need to add oil.

Buy the correct oil type for your car — check your owner's manual or the label under the hood for the viscosity (usually something like 5W-30). Unscrew the oil filler cap on top of the engine, insert a funnel, and pour in a quart. Wait a minute, then check the dipstick again. Add oil in half-quart increments until the level reaches the full mark. Do not overfill; too much oil can damage your engine.

How to check coolant

Let your engine cool completely — at least thirty minutes after driving. Never open the coolant reservoir when the engine is hot; the fluid is pressurized and can cause severe burns. Once cool, locate the translucent plastic coolant reservoir, usually on the side of the engine bay. You can see the fluid level through the plastic without opening it.

The reservoir has "min" and "max" marks. The coolant should sit between them. If it is below the minimum, unscrew the cap and add a 50/50 mix of coolant and distilled water, or use pre-mixed coolant. Add slowly and recheck the level. If coolant drops frequently, you may have a leak and should have a mechanic inspect it.

How to check brake fluid and power steering fluid

Both fluids sit in small, labeled plastic reservoirs near the back of the engine bay on the driver's side. Brake fluid is usually on the left; power steering fluid on the right. Both have minimum and maximum marks on the side. You can check the level without opening the cap — just look at where the fluid sits against the markings.

If either is below the minimum, unscrew the cap and top it off with the correct fluid type. Your owner's manual specifies which type to use. Do not mix fluid types. If brake fluid drops quickly, have your brakes inspected immediately — low brake fluid can mean a leak or worn brake pads. Power steering fluid loss is usually slower but still warrants a mechanic's check if it happens repeatedly.

How to check tire pressure

Find the correct pressure for your car on a sticker inside the driver's door jamb or in your owner's manual. This number is different from the maximum pressure printed on the tire sidewall — use the door jamb number. Check pressure when tires are cold, ideally in the morning before driving or at least three hours after you last drove.

Buy a tire pressure gauge at any auto parts store or gas station for under $15. Remove the valve cap from the tire, press the gauge onto the valve stem firmly, and read the number. If pressure is low, drive to a gas station and use the air pump. Press the pump nozzle onto the valve stem and add air in short bursts, checking pressure every few seconds. Overinflated tires wear faster and reduce traction, so stop when you reach the correct pressure. Replace the valve cap and move to the next tire. Check all four, plus the spare if your car has one.

What to do if a fluid is low

Low oil means you need to add oil immediately — driving on low oil can seize your engine and cost thousands to repair. Low coolant can cause overheating; add coolant and monitor the level closely over the next week. If it drops again, you have a leak.

Low brake fluid is a safety issue — have your brakes inspected before driving far. Low power steering fluid makes steering harder and can damage the pump; add fluid and watch for leaks. Low washer fluid is inconvenient but not dangerous; refill it at a gas station or auto parts store. If any fluid drops repeatedly within a month, a mechanic should check for leaks.

What to do if tire pressure is wrong

Underinflated tires (below the recommended pressure) wear faster, reduce fuel economy, and can overheat on long drives. Overinflated tires (above the recommended pressure) wear in the center, reduce traction, and make the ride harsher. Both reduce your car's safety and handling. Adjust pressure at a gas station air pump until all four tires match the door jamb number.

Tire pressure drops in cold weather — expect a loss of about one pound per square inch for every ten-degree drop in temperature. This is normal and does not mean you have a leak. If pressure drops more than five pounds in a week, or if one tire consistently runs lower than the others, you may have a slow leak and should have a tire shop inspect it.

Frequently Asked Questions

Can I check tire pressure on a hot tire right after driving?

No. Tire pressure rises when tires heat up from driving, so a hot-tire reading will be higher than the actual cold pressure. Wait at least three hours after driving, or check in the morning before you drive. If you must check after driving, add about four pounds to the cold-pressure number to estimate what a hot reading should be.

What if my car does not have a dipstick for oil?

Some newer cars use electronic oil-level sensors instead of dipsticks. Check your owner's manual to see if yours has one. If it does, the oil level appears on your dashboard or infotainment screen. You still add oil the same way — through the filler cap — but you check the level electronically rather than with a stick.

Do I need to check fluids if my car is brand new?

New cars lose very little fluid in the first year under normal driving. Check fluids every three months instead of monthly. Once your car reaches 50,000 miles, return to monthly checks. If you notice any leaks or warning lights, check fluids immediately regardless of age.

What happens if I use the wrong type of oil or coolant?

Using the wrong oil viscosity can reduce engine protection and fuel economy. Using the wrong coolant type can cause corrosion inside your engine. Always check your owner's manual or the label under the hood for the correct type. If you add the wrong fluid by mistake, have a mechanic drain and refill it as soon as possible.

Should I check fluids before or after an oil change?

Check fluids before an oil change so you know what levels you are starting with. After the oil change, wait a few minutes for new oil to settle in the pan, then check again to confirm the level is correct. This helps you catch any mistakes the shop may have made.