Checking and maintaining the anti-freeze for proper level and protection against freezing or boiling, are one of the most important fluids to maintain among many of the fluids in your vehicle. In this article we will show you how to check and monitor coolant level and protection.

Understand how to monitor temperature

Before checking the coolant make sure you understand how the system operates normally. Some vehicles have a temperature gauge and some have a warning light.

Temperature gauge
Temperature warning light

If there is a gauge, the best guideline to use is that 1/2 way between cold and hot on the gauge should be normal operating temperature.

Normal temperature

Warning lights usually don’t come on until it’s hot, unfortunately you can’t monitor the engine temperature until it’s too late.

Where to check the level

Locate the area to check the coolant. Some vehicles have the fill at the radiator and some have a separate reservoir.

Radiator fill
Seperate reservoir


When checking coolant level, always make sure the engine temperature has cooled down or sat over night to prevent severe burns from opening a hot system.


Engines run at 220°F and have 18 psi of pressure when hot! These temperatures can scald you and create sever burns if opened while hot.

Find the level indicator somewhere on the tank or reservoir.

Radiator level
Reservoir level

And determine where to fill it when cold making sure not to over fill. Leave a small amount of air in the top of the reservoir for the coolant to expand when it gets hot, this will keep the fluid from pushing out of the overflow.

Sample the coolant

Remove the cap to access the coolant and check it for proper protection from freezing or boiling. Put the tube of the hydrometer into the coolant, squeeze the ball to let the suction pull a sample into the clear measuring area.

Remove cap to check
Check anti-freeze

You can obtain a hydrometer from your local parts store to check the protection level for as little as $5.00. A 50/50 mixture of antifreeze and water will protect your engine to -30°F

If you need to top up the level make sure you purchase the correct type for your vehicle. Check the owners manual or ask your parts specialist at the parts store.


You can buy premixed or full strength antifreeze. You get more for your money to buy it full strength.


Anti-freeze needs to be mixed before it protects against freezing or boiling. Mix 50% water to 50% anti-freeze then top up.