The radiator is the heart of the car's cooling system, which also includes a fan, water pump, thermostat, hoses, belts and sensors. It directs the coolant into the cylinder heads and towards the valves to absorb their heat, return it to the radiator and dissipate it safely. For this, it is important to maintain an adequate level of fluid in the radiator, and this means that you will have to check it and add fluid if necessary.
Steps
Method 1 of 2: Check the Fluid Level in the Radiator
Step 1. Park your car on a level surface
Ideally, you should do this after driving it for a short distance. You should check the coolant or antifreeze level when the engine is warm, not hot or cold. If you have driven the car a longer distance, let the engine cool for a few hours.
Do not leave the engine running when checking the radiator level, and never try to check the level when the engine is hot
Step 2. Raise the hood
Step 3. Look for the radiator cap
This is a pressurized cap near the top of the radiator. In more modern cars the cap is labeled; if it is not indicated in yours, check the user manual to find it.
Step 4. Wrap a rag over the cap and remove it
The radiator and cap absorb the engine heat from the coolant; with a rag you will avoid getting burned.
Step 5. Check the fluid level in the radiator
The coolant should almost reach the cap. If "Full" is engraved on the metal of the radiator, that is the level that the liquid should reach.
Step 6. Find the additional tank cap and remove it
In addition to the radiator reservoir, most modern cars have an additional reservoir to accommodate the expansion of the radiator fluid as it warms up. Normally it should be almost empty. If the coolant level is low in the radiator and high in the additional tank when the engine is cold, take the car to a mechanic right away.
Step 7. Check the freezing and boiling points of your coolant
Over time, the ability of the radiator liquid to absorb and dissipate heat decreases. You will be able to test those points with an antifreeze hydrometer. Read the directions under "Checking the Coolant Protection Level".
Step 8. Add coolant if needed
Add the liquid to the additional tank if your car has one, otherwise add it to the radiator (you could use a funnel to prevent leaks). Under normal driving conditions, you should mix equal parts antifreeze and distilled water. In colder climates you can go up to 70% antifreeze, but you shouldn't exceed them.
Do not add liquid if the engine is still hot
Method 2 of 2: Check the Coolant Protection Level
Step 1. Squeeze the bulb of the hydrometer
This will expel the air.
Step 2. Insert the rubber tube of the hydrometer into the liquid
Step 3. Release the bulb
This will draw liquid into the hydrometer, and raise the needle or plastic ball inside it.
Step 4. Remove the hydrometer from the coolant
Step 5. Read the freezing or boiling point on the hydrometer
If your hydrometer uses a needle, this should indicate a specific temperature or range. If you use a series of plastic balls, the number of balls that can float indicates the effectiveness of the antifreeze protection. If the level is too low, you will need to add liquid or replace it.
You should test the level of protection in spring and autumn, and more often if you drive in extreme conditions
Advice
- Although the terms "antifreeze" and "coolant" are used interchangeably, antifreeze is the product that needs to be mixed with water, while coolant refers to the solution.
- Most antifreeze are green; the long-lasting ones, however, are orange or red. The difference between a regular and a long-lasting antifreeze, aside from the color, is the amount of rust inhibitor and other additives they contain.
Warnings
- Most antifreeze contain ethylene glycol, which is toxic to humans and animals. Dispose of used antifreeze properly.
- If you notice liquid under the car that is the same color as the antifreeze, or you notice a sulfur smell, if you hear a whistle or if the temperature gauge reads too high, take the car to a mechanic right away.
