How to Check Radiator Fluid in a Car

Is your car ready for hot weather? It’s easy to check radiator fluid level in both newer and older cars. Check the fluid when the engine is cool.

Check radiator fluid when the car engine is cool

Coolant prevents a car engine from overheating in the summer.

WARNING: Never remove a radiator cap when the engine is hot. The system is pressurized. Removing the cap on a hot radiator causes scalding liquid to spray out. The potential for injury is great.

Check Radiator Fluid Level

You can check radiator fluid in most newer cars simply by looking under the hood. You’ll see a semi-translucent, white plastic overflow tank next to the radiator. The tank will have a low and high mark. Fluid should be somewhere near the high or full mark.

If your vehicle doesn’t have an overflow tank, you’ll need to peek inside the radiator. Wait until the engine is cool, then twist off the radiator cap. In most cases, if you can see fluid when you look into the radiator, you’re good to go.

Why Water Isn’t Ideal

Knowing that you have adequate fluid tells you nothing about whether it’s the right mix. Water in the radiator isn’t enough to maintain optimal engine temperature. Car’s need coolant to do that. True story: coolant and antifreeze are the same thing. In summer, radiator fluid is called coolant. In winter, it goes by the name antifreeze. Go figure!

Radiators need a mix of 50 percent water to 50 percent coolant. If you’ve been bringing your car into our Battle Ground store for regular oil changes and maintenance, we’ve been checking that your radiator has the right amount and mix of fluid.

Coolant raises the boiling point of the water from 212 to 275 degrees Fahrenheit. It also lowers the freezing temperature, keeping your radiator from turning into a block of ice in cold weather.

Adding Radiator Coolant

You’ll need to top off your radiator coolant it’s too low. To do this, buy a coolant that’s premixed at a 50/50 ratio. When the engine is cool, open the overflow reservoir and pour until just below the high mark on the tank. On an older car, add the fluid directly into the radiator.

Flushing Out the Radiator

Keeping the radiator antifreeze topped off protects your car’s engine from overheating and freezing. In order to do its job, the radiator needs periodic flushing to remove gunk. How often? Consult your car’s manual. Many manufacturers recommend flushing every 30,000 miles or so.

Depend on Battle Ground’s Automotive Maintenance Experts

Depend on Grease Monkey for all your automotive maintenance. We’ll keep track of your vehicle’s maintenance schedule. Our technicians check your vehicle’s manual, ensuring your wheels are always ready to roll. No appointment is needed. Come into our shop today!