7 fluids you should check in your car before winter hits

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Winter presents unique challenges for your vehicle's maintenance. Among the crucial aspects to consider during this season are the fluids that keep your car running smoothly. Here's a guide to the essential fluids that require special attention during winter.

Before you start

  • Look in the owners’ manual before adding fluids – whether that’s in the glovebox or online. It will provide a guide to all the cap icons in the engine, to matching the right fluid to the correct part of the engine.
  • When checking fluids, make sure the vehicle is parked on a flat surface. You won’t get an accurate reading on an incline.
  • Check fluids at engine operating temperature, particularly when it’s very cold. Run the motor for a while, then turn it off and do your tests.

1. Engine Oil

Your engine's lifeblood, especially in cold weather. As temperatures drop, oil tends to thicken, making it harder to properly lubricate all the moving parts. Changing your oil according to the manufacturer’s directions is an important part of caring for a car, as is choosing the right oil and make sure it’s maintained at the optimal level.

And if you live somewhere it gets very cold, consider using a winter-grade oil that's formulated to perform better in colder temperatures.

2. Coolant

Coolant is a mix of water and antifreeze, combined in specific proportions that can vary by vehicle - it’s important to get it right, so check the manual. In winter, the coolant lowers the engine’s freezing point, which prevents the radiator from freezing up and potentially cracking.

Making sure the coolant level is correct will safeguard your engine as we move into the winter months, but be sure to check and top up the coolant level using the expansion tank, as the system operates under pressure and opening the radiator cap can cause hot coolant to fly out.

3. Transmission fluid

Like your engine, the transmission is full of moving parts and needs proper lubrication to keep everything running smoothly. And, like the oil used to lubricate the engine, transmission fluid can thicken in cold weather, affecting gear changes and overall performance.

In an older car, check the fluid level and condition regularly, and if necessary, consider flushing and replacing it according to your vehicle manufacturer's recommendations. However, if you have a newer car, it may well have a sealed transmissions which need professional servicing. Check your owners’ manual for more information on your transmission.

4. Brake and power steering fluid

Brake and power steering fluids are both hydroscopic, meaning they absorb water from the atmosphere, which can reduce their effectiveness. That’s the last thing you want on wet or icy winter roads, so replace brake fluid every two years. Check that the brake fluid is at the right level, between the maximum and minimum marks, and flush the system if it's discolored or contaminated.

Thickened power steering fluid will cause your steering to become heavier, and you might notice it gets lighter as the car warms up. Check the fluid level and condition, and top up or replace it as needed, but remember that while brake and power steering might seem the same, they are in fact, quite different and you should always use the correct fluid recommended for your car.

6. Windscreen washer fluid

Visibility is crucial during winter driving, so ensure your windscreen washer fluid reservoir is filled with a winter-grade fluid that won't freeze in low temperatures.

Many Kiwis just fill up the washer fluid container with water, but in winter pure water will freeze up. Using a washer fluid additive that’s designed for the job will not only improve visibility, it will also help extend the life of the wipers.

7. Battery electrolyte

Most modern vehicles have sealed batteries, so no maintenance is usually required. But for some older cars, batteries need to be topped up with distilled water. If the battery does require water, it will have removable caps on top. Keep it topped up, particularly in winter when heating and lights put extra load on the battery.

Having the right fluids, at the right levels, in your vehicle, reduces the risk of a breakdown – and the last thing you want is to be stuck on the side of the road in cold winter weather. Regularly inspecting and maintaining these essential fluids will help ensure your vehicle performs reliably throughout the winter months, keeping you safe on the roads. If you're unsure about any aspect of fluid maintenance, consult with a qualified mechanic or refer to your vehicle's owner's manual for guidance.