Brake Fluid is Black or Brown: Top Causes & Solutions

Welcome to my post on brake fluid – a crucial component in every vehicle. Not only does it allow drivers to slow down or stop, but it’s also essential for ensuring a smooth ride. However, have you ever noticed your brake fluid turning black or brown? If so, it could be contaminated and cause your brakes to malfunction.

We’re here to discuss why this happens, common causes and why it’s essential to keep your brake fluid in tip-top shape. So buckle up and let’s dive in!

What Causes Brake Fluid To Turn Black Or Brown?

Brake fluid is an essential component in every vehicle that works by transferring power from the brake pedal to the brakes. However, if you notice brake fluid turning black or brown, it is a warning sign of potential issues that require your attention.

Here are some of the primary causes that can lead to brake fluid turning black or brown:

Normal Aging

Brake fluid naturally darkens with age due to contamination in all brake systems. The fluid collects grime and debris over time, causing a change in color. This usually takes a couple of years to happen but can vary depending on driving habits. It will darken from clear/golden to a darker gold. To avoid serious complications, replace your brake fluid regularly before it becomes brown or black.

Moisture Contamination

Heat in the brake line can cause moisture to boil, which darkens the fluid and introduces air into the hose. This can cause corrosion in the braking system and reduce effectiveness.

Deteriorating Fluid Hoses

Some fluid hoses are made of rubber and can deteriorate into the fluid, causing it to darken and become less effective.

Normal Heating

Friction generated when applying the brakes generates heat that can cause brake fluid to darken gradually.

What Are The Dangers Of Driving With Black Or Brown Brake Fluid?

Driving with blackened or brown-colored brake fluid is dangerous since it could signify contaminants within your car’s hydraulic braking system. The consequences of driving when you’re not applying enough pressure on your brakes because of dirty or low-quality fluids can be disastrous as they can limit their functionality.

Here are some of the most common risks associated with driving with dark-colored brake fluid:

  • Reduced braking performance: Contaminated fluids have lower boiling points, making them more susceptible to compressing. This means they’ll take more time for you to stop your car once pressure is applied leading to increased chances of accidents.
  • Spongy Brake Pedal: It’s quite difficult driving with a soft brake pedal feel as you’re not sure whether the car will stop immediately upon applying brakes. This sponginess likely comes from air bubbles within your brake lines due to poor-quality fluids and can lead to inconsistent pedal responses affecting safe vehicle control ability.
  • Brake fluid leaks: Darkened fluids often deteriorate or weaken hoses that carry them between hydraulic components such as the master cylinder, calipers, and ABS unit- causing malfunctioning parts and leading towards serious damages if left unattended for too long.

When Should I Replace My Brake Fluid?

To keep this critical component performing at its best and ensuring that you are safe on the road, experts agree that you should replace your brake fluid every two years regardless of how much mileage you have driven. Most car manufacturers also specify replacement intervals in their owner’s manual that should be followed.

If you live in a hot and humid climate or an area subject to extreme temperature ranges, it is advisable to conduct regular check-ups on your brake fluids. Your trusted mechanic may recommend more frequent replacements if they find any deterioration or contaminants inside.

Here are some factors that could influence how often your car’s brake fluid needs changing:

1. Driving Habits

If you tend to drive aggressively such as frequently braking hard or driving at high speeds for extended periods can cause your brakes to work overtime. That’s why constant usage puts more pressure on both your brakes and fluids than someone who drives more conservatively.

2. Type of Brake Fluid

Older cars tend to use a DOT3-type brake fluid that absorbs moisture faster than newer ones do. This type of fluid has a lower boiling point and can accelerate corrosion leading to early breakdown.

3. Environment

Hot climate causes more humidity which attracts moisture into the system causing the reduction in longevity before needing replacement compared with those in colder climates.

How Do I Replace My Brake Fluid?

Replacing your brake fluid every two years or as needed is one of the easy preventive maintenance tasks you can perform without assistance. However, if you’re not mechanically inclined and feel uncomfortable about working on hydraulics, it’s best only to take your car to a qualified mechanic. But replacing brake fluids could be done with these basic steps:

  1. Determine the type of braking system: Your car has a unique braking system, and it’s crucial to understand its requirements before replacing the brake fluid. For instance, if your vehicle has drum brakes, you’ll need to know what type of drum brakes it uses.
  2. Look for correct lubricants: Purchase replacement brake fluids designed to work with your car’s make and model.
  3. Gather necessary tools: A jack, stands, rubber gloves, clean pot/cup for the spent hydraulic liquid are required items for this procedure.
  4. Prepare your workplace: Before getting started, set up a safe workspace conducive toward successful workmanship. Follow all-round safety precautions accordingly.
  5. Drain contaminated fluids: Disconnect the emptying hose from the caliper and attach it onto a catch-basin to collect all drained liquids.
  6. Refill with new brake fluid: Slowly refill the system until clean clear liquid comes out when purging obtainable pumped-up clear liquids in haste or flushing out dirty used ones.

Brake systems are hydraulic and have many working parts that wear over time due to heat, moisture along with normal use; therefore, caution must always be taken while replacing the fluid since airlock could occur when refilling or pumping after new brakes have been installed causing mishap or failure.

What Are The Costs Of Replacing Brake Fluid?

The cost of replacing brake fluids varies from one vehicle to another, and this is because prices vary depending on the composition and size of their fuel line systems. On average, a basic brake fluid replacement service would cost around $50-100. However, the expense may differ due to various factors such as system leaks, necessity of flushes or specialty services, and vehicle model.

If you’re unsure how much it will cost to replace brake fluids in your car or truck, we recommend consulting with local auto repair shops that offer trustworthy pricing information before deciding who will work best for your needs. Here are some factors that could influence the overall cost of replacing brake fluids:

  1. Vehicle make and model: The prices for parts and labor can differ greatly depending on the make and model of a vehicle. This is because different brands require different types of brake fluid.
  2. Fluid type: There are a variety of brake fluids available today that can range from organic-based to silicone-based solutions. The price difference between these options may also vary.
  3. Condition of your brake system: If there are any leaks in the system, then additional repairs or part replacements may be needed before a full fluid change-out can occur.

How Can I Prevent My Brake Fluid From Turning Black Or Brown?

Keeping your car’s brake fluid clear is crucial in maintaining it properly. By implementing regular preventive measures, you can ensure that your vehicle runs efficiently and steer clear of potential issues in the future.

Here are a few ways to help keep your brake fluid clean and healthy:

1. Regular Check-Ups

Make it your priority to examine your brake system every six months or when you’ve covered 10,000 miles. This allows you to notice any pollution indications beforehand and take corrective measures before it exacerbates.

2. Avoid Harsh Chemicals

Be careful while handling harsh chemicals near your hydraulic system to prevent significant damage. Make sure to avoid using cleaning products and power washers that are not suitable for your car’s cleaning as they may contaminate fluids or parts of your vehicle.

3. Replace Fluids Over Time

According to various experts, changing the liquids in your car once annually is crucial. It guarantees that you have new lubricants that improve functionality and avoids accumulation of harmful materials for prolonged usage.


To sum up, brake fluid plays a vital role in ensuring safe braking distance on the road. It is crucial to inspect discoloration factors such as moisture contamination, deteriorating rubber lines, and normal heating processes to avoid black or brown brake fluid. 

By adhering to these fluids’ expiration dates, one can significantly reduce rusting risk inside fluid chambers of different brakes and preserve auto-mechanical parts. 

Replacing contaminated brake fluids is a simple task that takes less than an hour and helps prevent potential damages caused by dirty clogs affecting the car’s hydraulics.

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