Recognizing Contaminated Brake Fluid And Brake Problems

Posted on: 20 October 2017

Few components on your car are as vital to your safety as the braking system, but it's also one of the least understood. For many car owners, understanding what the brakes are doing or recognizing when there's something wrong can be a real challenge. Sometimes, troubling car symptoms can be attributed to the brakes even if you don't realize it. For example, if your car feels like it's hesitating, dragging, or underpowered, it may not be the engine at all. It could be contaminated brake fluid.

How Does Brake Fluid Get Contaminated?

There are a number of ways that your brake fluid may have gotten contaminated. For example, if you inadvertently poured coolant in the brake fluid reservoir, that mixture of fluids can cause the contamination. If the reservoir wasn't closed all the way, condensation can settle into the fluid, causing water contamination. In addition, you may actually have a hole in the line somewhere that's drawn dirt and other contaminants into the lines, causing a buildup of particles that can lead to problems.

What Are The Signs Of Contaminated Brake Fluid?

One of the reasons that contaminated brake fluid can be hard to diagnose is because the symptoms are intermittent. You may not notice it on cooler days or during particularly short trips down the road. However, when the weather warms up, your brake system gets warm, or you're on the road for a long time, you'll start to notice problems.

As the temperature of the brake fluid increases, the contaminated fluid will expand. This can increase the pressure in the braking system. When that increased pressure gets high enough, it can actually start to engage the brakes even if you're not pressing the pedal. That causes your car to feel slower, sluggish, or somewhat underpowered because it will hesitate when under acceleration and slow down or feel like it's dragging.

If this sounds like what your car is doing, take the top off the brake fluid reservoir and look at it. When the fluid is contaminated, you'll see the difference in its appearance. It may look dirty, separated, or thick. You might also notice that the gasket on the reservoir cap is thicker, swollen, or otherwise altered.

How Do You Deal With Contaminated Brake Fluid?

The only effective way to correct a problem with contaminated brake fluid is to flush out the entire brake system with clean fluid, ensuring that all of the contaminated fluid is drained out. If you have any rubber lines in the system, you'll need to replace those, too. The rubber can actually deteriorate due to the contamination, so it's important that you remove them. If possible, replace them with stainless steel lines so that you eliminate that risk in the future.

Once the whole system is flushed out, refill it with fresh brake fluid so that your fluid levels are where they belong. Just remember that any time you flush brake systems or replace lines, you'll have to bleed the brakes to ensure that there are no air pockets in the system. Air pockets can lead to brake failure, so take the time to bleed all four brakes before you put the car back on the road. When you're done bleeding them, top off the brake fluid in the reservoir, because there will be some fluid loss in the process. There are self-bleeder kits available at most auto parts stores and service centers if you want to do this on your own.

If you're not comfortable doing the work yourself, talk with a local auto repair shop, such as Valley  Express Auto Repair, about doing it all for you. They can check the fluid, purge all the contaminated fluid from the system, and then restore your brakes.

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