Blog Car Care Advice How Does the Cold Weather Affect Brake Fluid?
Car Care Advice

How Does the Cold Weather Affect Brake Fluid?

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As we settle into winter, it’s time to dive into a topic colder than a snowman’s stare (and one you might not always think about) — the brake fluid. 

This little hydraulic hero plays a significant role in keeping you and your beloved vehicle safe on winter roads. But when the temperature dips to zero, your brake fluid turns from a reliable liquid into a stubborn slushie that’s not exactly keen on stopping your winter wheels with grace.

So grab your hot cocoa and discover how the cold weather affects your brake fluid and whether you need any special fluid to keep you safe on wintry roads. 

This Article Contains:

Let’s brake in. 

3 Frosty Impacts of Cold Weather on Brake Fluid

Here are three ways the winter weather can affect your trusty brake fluid: 

1. Reduced Brake Performance 

Even though brake fluid doesn’t freeze like washer fluid, it does tend to thicken or congeal if the temperature reaches -22C or -30F. When that happens, the brake fluid may fail to transfer the full force from the master cylinder to the wheels. This increases your braking distance, and the brake pedal may feel stiffer

Additionally, newer vehicles with ABS may fail to modulate the brake pressure as the thickened hydraulic fluid struggles to circulate through the brake system

2. Worn Brake Lines

Commonly used brake fluids like DOT 3, DOT 4, and DOT 5.1 are hygroscopic. 

What does that mean?
These brake fluids can easily absorb moisture and corrode your brake lines. Excessive damage to a brake line can cause water to seep into the braking system. 

But here comes the bigger problem.

Water has a higher freezing point than brake fluid. So when there’s a low temperature outside (32°F or less), water can freeze inside the brake lines or brake booster, which will be pretty expensive to fix

A damaged brake line plus degraded hydraulic fluid can reduce your braking capacity, endangering your safety while driving — whether it’s over black ice or otherwise. 

3. Overheated Brakes 

Even though it feels counterintuitive, winter weather can leave you with hotter brakes and brake fade.

Here’s how: 

Any moisture in the brake fluid can lead to the formation of air pockets. As a result, you need to apply more force or keep the brake pedal engaged for longer to prevent your car from sledding.

But as you keep the brake pedal pressed for longer, the braking system can get really hot and overheat, even in a low temp environment.  Excessive heat can wear off your brake pads and cause the brake rotor to warp. You may also experience squeaky brakes or smoke from the brake pads. 

But will switching up your brake fluid fix these issues?
Let’s find out next. 

Do You Need a Special Cold Weather Brake Fluid?

Unlike washer fluid, brake fluid is formulated to retain its viscosity over a wide temperature range. So, unless the temperature in your area plummets to -40𝆩F, the chances of brake fluid freezing are highly unlikely. 

That said, you do need the right kind of brake fluid, recommended by your manufacturer, to keep the brake components well-lubricated under freezing weather conditions. Additionally, you need to keep a check on the brake fluid level and its quality, ensuring timely changes during scheduled maintenance. 

That brings us to the next question: 

How Often Do You Need to Change Your Brake Fluid

Ideally, you should follow your manufacturer’s brake service recommendation. Different manufacturers may have varying suggestions.

However, a couple of factors could affect the frequency of brake fluid change: 

But is brake fluid the only brake component affected by freezing temperature?

How Else Does Cold Weather Impact Your Brakes 

In addition to losing brake fluid integrity in low temperature conditions, your brakes can also suffer from the following: 

1. Corrosion and Rust

Exposure to road salt and other de-icing agents, common in freezing winters, can contribute to corrosion and rust on brake components. Excessive rust on brake components like rotors or brake drums can result in squealing or squeaking sounds and your brakes losing power. 

Tip: It’s a good idea always to check the condition of your brakes while your car is jacked up for a tire rotation. 

2. Brake Pad and Rotor Wear

Cold weather can harden the material of brake pads, causing it to wear out quickly and resulting in brake fade. Likewise, excessive rust build-up on the rotors can lead to a brake problem called pitting — the formation of small, localized depressions or cavities on the brake rotor surface. 

3. Frozen Brake Calipers

In extreme cold, moisture in the braking system can freeze, leading to frozen brake calipers. This can cause uneven braking or, in severe cases, result in the brakes being partially or completely locked.

4. Undercarriage Damage 

If you regularly drive on sleet-covered roads and don’t wash your car during winter months, the accumulated dirt and road salt can corrode your car’s underbelly. Prolonged exposure to such corrosion can affect your brake pads, parking brake, and muffler. 

However, taking proactive measures could ensure your brakes stay your reliable companion during low temp conditions. 

5 Handy Tips to Chill-Proof Your Car Brakes

Here are a few ways to keep your brakes in top shape in the cold weather: 

  1. Maintain adequate brake fluid level: Fill up the brake fluid reservoir with the right brake fluid. But avoid overfilling it to prevent spills. Ensure that other essential fluids like transmission fluid and engine oil are also topped up.
  1. Protect your braking system: Park your vehicle in a garage or shelter during extreme cold. You can also invest in a thermal blanket to keep the brake fluid reservoir insulated. 
  1. Keep the brake components clean: Use a brake cleaner to keep the calipers, rotors, or drums free of brake dust, grease, etc. 
  1. Check for any leaks: Look for any fluid leaks and get a brake repair service if needed to prevent further complications in cold weather.
  1. Schedule a professional brake inspection: Visit an auto repair shop for a brake service before the onset of freezing temperature months. This can help you identify and address any potential brake problem.

Note: Ensure your tires have adequate tire pressure, as it can affect the traction and braking force in winter months. 

Safeguard Your Brakes in Cold Temperature 

Using the correct brake fluid and taking proactive measures to maintain your brakes can help you navigate icy roads with confidence. Remember, a well-maintained brake system is not just a matter of convenience — it’s a commitment to safety and control. 

Don’t have time to visit a repair shop?
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