How to Check a Car's Radiator Fluid

Radiator Fluid being poured into a car

Do you know where to find your car's radiator fluid? This may seem like a simple thing, but many people do not. If you are unaware of how to check your car's radiator fluid, you may regret it later. Problems with radiator fluid that seem small now can lead to problems that are anything but small in the future. So what can you do to prepare yourself and avoid trouble down the road? Luckily for you, checking your car's radiator fluid is simple and can be done by anyone with the proper knowledge.

Checking the Fluid

First, let your engine cool down if it has been used recently. In particular, do not do anything while your engine is running, turn it off if it is still on. Once you turn it off, wait an absolute minimum of 30 minutes before opening your car's hood. This step is very important, and if you do not follow it you may be seriously injured. If it is safe to do so, continue.

Use the hood release control on your dashboard, then open up your car's hood. At the front of your car, directly under the hood, there should be a latch that you can use to pop the hood open. Pull it, then as you are pulling it, lift up the hood. Secure the hood using the attached prop rod, and continue.

Your car should contain a reservoir tank for storing coolant. This tank will usually be right next to the radiator, made out of plastic, white, and only partly opaque, so you can tell how much fluid it contains.

Inside the tank is a mixture of water and antifreeze at a 1 to 1 ratio. This mixture flows through your radiator and engine, absorbing heat produced by your engine. By traveling through your radiator, which is designed to spread out the coolant and cause it to be exposed to as many surfaces as possible, it allowing the heat to radiate away, your car's coolant keeps the engine from overheating.

There should be several labels visible on your radiator fluid tank. Because your engine is cool right now, the level of fluid should be at the level marked "cold." If the engine were currently hot, the fluid would be at the level marked "hot" — but because you were careful to allow your engine to cool down before even opening the hood, this is not the case.

Older Cars

Cars from before 1970 will often not have a reservoir for radiator fluid. Instead, radiator fluid is stored in the radiator. As a result of this, the usual instructions for checking radiator fluid in a car from 1970 or earlier will not apply.

In this case, after waiting for your car engine to cool (even more important in this case) and opening up your hood, you should look for a cap on your radiator. It should be near the front of your engine. Unscrew the cap and look inside. Ideally, the coolant should reach the top of the reservoir, nearly up to the cap you just unscrewed.