How to Check a Car's Radiator Fluid

Your vehicle's radiator cools the water and antifreeze fluid. The mixture of cooled fluid is pumped into the car's hot engine and is then sent back to the radiator to be cooled. The cycle is continually repeated to prevent your engine from overheating. Radiator fluid should be checked periodically.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Antifreeze tester

1. Open the hood of your car and secure it with the prop rod. If the engine is hot, allow it to cool for 15 to 20 minutes. Never open the radiator cap when the engine is hot.

2. Locate the radiator fill cap. In most cars, this will be on either side of the top of the radiator. Some cars have the radiator fill cap on the coolant recovery jug.

3. Twist the radiator cap counterclockwise while pressing down and allowing any remaining pressure to vent out. Slowly continue turning while pressing until it stops. Remove the cap.

4. Look into the radiator fill neck to determine the level of the fluid. If it is lower then the top of the hole, fill it with a 50/50 mixture of antifreeze fluid. If the level is at the top, your radiator does not need any fluid.

5. Draw some of the fluid into an antifreeze tester and note the level of freeze protection. Twenty degrees Fahrenheit is good for most cars.

6. Replace the radiator cap. While pressing down, turn clockwise until the cap stops.

7. Check that the fluid level in the coolant recovery jug also reaches the proper level on the indicator.

Tips & Warnings

• Check the radiator cap seal and clean any build up of corrosion. Always use the same pressure rated cap if replacement is necessary.
• Never open a radiator cap on a hot or overheated engine. Allow it to cool for 15 to 20 minutes. Opening a hot radiator cap will cause the fluid to spray out quickly and could cause severe burns.

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[Planet]

on 7/30/2008 P.S. I might be wrong, so don't try it! I was more just wondering if anyone else had heard this before.

[Planet]

on 7/30/2008 I worked at a full service gas station in the past, and was told that you could check the radiator if the engine was warm by carefully removing the cap while the engine was running. I always used a towel over the cap in case, but I was never scalded.

[Laur]

on 12/12/2007 Just wanted to say THANK YOU to whomever wrote this article -How to Check a Car's Radiator Fluid-. I know nothing about cars and had a problem with mine (thought might be the radiator?) and searched for a couple of days on the internet, to find out I was correct because of this article, it was the rad(poor maintenance on my part, but now I know). Easy to read and understand for someone with a lack of knowledge about cars. Thanks again for saving me from being stranded on the side of the road!!!!