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How to Check Your Car Antifreeze Levels and Inspect for Leaks

Keeping your vehicle topped up with the right stuff is an important part of winter driving safety.

We address how to properly check your antifreeze levels, and what to do if they’re low.

Antifreeze 101

All fluid levels should be checked and replenished as necessary, just like motor oil. Over time, antifreeze can lose its ability to prevent freezing in cold winters, and can also become corrosive to the interior. Maintaining a 50/50 mixture of quality anti-freeze and water is what your vehicle needs to provide the right protection in temperatures as low as –35 C.

How often you need to flush your cooling system and replace with new product depends on your climate. Most Canadians need to do this every 2 years. However, if you don’t know how long the coolant mixture has been in the system, or if you have any doubts about its effectiveness, it’s time to drain and discard it. You can either take it to a mechanic to perform this service, or follow the directions on your vehicle’s owner manual.

How to check your antifreeze

If your coolant light comes on, your first action should be to check if your levels are low. First, allow your vehicle to cool down – if you don’t, hot pressurized liquid can spray out if the vehicle. Begin by locating the coolant reservoir under the hood near the front or side of the engine. It is usually transparent, with line near the bottom labelled “cold” and a line near the top labelled “hot.” Remove the cap and check to see if levels dip below the “cold” line. If so, the mixture is too low.

Low coolant is usually the result of a leak. As your vehicles’ hoses, gaskets and seals age, they tend to become prone to leakage. A leak needs to be found and fixed as soon as possible.

How to identify leaks

  • Look under the vehicle to check for liquid on the ground below the front end. Shine a flashlight on the area or feel for wetness – if you spot wetness on the driveway, open the hood and check the condition of the hoses leading to the coolant recovery reservoir
  • Feel the underside of the radiator for leaks or surrounding rust. Rust may indicate old leaks that have dried. Water generally evaporates quickly on a hot radiator, so the problem may be newer than you think
  • Check your pressure cap. If you’ve noticed your vehicle overheats easily, ask your mechanic to pressure-test your cap to see if it’s working properly
  • It is a good idea to check all the hoses under the hood regularly, whether your coolant is low or not. Just remember to do this only when your vehicle is cold. If you find a hose that’s soft to the touch, lumpy, cracked, or otherwise damaged, it needs to be replaced. If you locate a hose that is collapsed but bounces back when you remove the pressure cap, it is likely a problem with the cap or the coolant recovery system, rather than the hose

If a visual inspection reveals no leaks but your coolant light continues to be lit, take the vehicle to a mechanic to get it checked – this means there is a problem with the sensor light or some part of the coolant system. Either way, don’t allow the problem to persist.

Prep your vehicle for winter driving

Just like you wouldn’t risk driving with an inadequate coolant supply this winter, don’t leave other parts of your vehicle unprepared for the dangers of the season. Before you set off on the winter road, refer to this list of preparations to ensure your vehicle is ready for winter driving, from your brakes to your headlights.

How to Check Your Car Antifreeze Levels and Inspect for Leaks

Car antifreeze, also called coolant, is responsible for keeping your engine from overheating in summer and freezing in winter.