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How Often Should I Change Brake Lines on a Mountain Bike?

Front wheel of a bicycle with brakes.

My first mountain bike was six months old when I changed its brake lines. I changed them because I had frequent brake failures with the bike. I didn’t know how soon I needed to change the brake lines. Cycling a mountain bike with faulty bike lines is dangerous, and unfortunately, I didn’t know how to determine if the brakes were defective.

A few cases would force anyone to change their mountain bike brake lines. Brake lines are critical because they keep your brakes working well. So you should change your mountain bike brake lines as soon as you notice that the brakes’ performance is relatively low or when you see some liquid below your bike’s brakes.

Here are a few essential things you need to know about your mountain bike’s brake lines and how to change them when they are no longer working for you. 

What is a Brake Line and What Does it Do? 

Different parts of mountain bike brakes.

The brake lines are among the essential parts of your MTB with a hydraulic disc brake system. A single brake line error could mean that your brakes can stop working when you need them the most.

Mountain cyclists are not involved in many accidents, but 10 percent of these accidents are fatal and need hospitalization, according to research.

We know that the primary job of your mountain bike brakes is to slow down or stop your bike when you need to. But what do brake lines do?

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The brake lines are as important as the brakes; they are the heart of the braking system; when you step on a mountain bike’s brake pedal, the brake lines will use hydraulic pressure to transport brake fluid from the cylinder to the calipers.

The calipers subsequently clamp the rotors slowing down your bike.

Possible Reasons Why You Need to Change Your Brake Lines

2 brakes lines for a mountain bike.

Bike brake lines are made of steel to withstand extreme hydraulic pressure. Steel is strong, durable, and can withstand a lot of stress.

Unfortunately, according to the National Center for Biotechnology information research, “although steel provides high resistance to corrosion, it can corrode in the long term given the right coinditions,” with elements such as moisture, presence of electrolytes, metallic connections topping the list.

Experts also indicate that steel corrodes over time because it does not occur naturally. This is reason enough that your brake lines need changing when the time comes to do so. It’s also a brilliant idea to check them frequently to ensure they’re working properly.

Other reasons other than rust include;

  • Cracks and bulges: The hydraulic oil lines that flow from the brake lever to the brake pads are a common element to replace. Over time, these lines might become brittle and fracture. During a fall, the lines may be damaged or pinched.
  • Brake fluid leaking: If you notice some brake fluid build-up under your bike, it means that your brake lines need to be checked or replaced. Leaking may cause you to feel a spongy lever action. It might also take longer to slow down or stop the bike.
  • Age: Old brake lines are prone to rust, breaks, and other operational inefficiencies. The steel may weaken over time and it’s a good idea to ride with a new set after some time of use.
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How often you replace your brake lines will depend on the extent of use of your mountain bike and the underlying problem. 

How Do You Change a Brake Line on a Mountain Bike? 

Brake kit and syringe for a mountain bike.

You will find that changing a brake line on your mountain bike is not like changing a mechanical brake. You will not need a single universal tool to make the conversion successful. 

Over the years, I have had to change my brake lines several times. Therefore I have compiled a set of tools to make my work easier. 

My master toolset is not as complicated, and you can have yours too. At first, I didn’t have a master set of tools – I did not know how to do so.

The conversion master tool that works best for me is Shimano, Park, and avid tools. I also have some syringes and transparent tubing from a pharmacy or any medical supply shop. There is even a  complete kit online to make your work easier when bleeding your brakes.

Now that you have all the tools that you need, here’s what to do;


Tools for changing mountain bike brakes.

First, you will need to prepare all the tools you need for the conversion. The tools are categorized into the cutting tools, pools for inserting in the hose, and tools used to bleed out the brake fluid. 

Don’t worry if you have to buy many tools at once; after all, they will all belong to your master toolset. The tools will help you every time you want to change the brake lines.

Set all these tools aside before you begin your work to avoid confusion.

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Hose Changing

A person repairing brake of a mountain bike.

You will first need to retract your brake pads. To do this, you will need a pad piston to press gently to retract both the piston and the pads. 

If you are using the newer Shimano calipers, you will need to be extra careful because they are made of ceramic. Try to ensure that they retract as straight as possible to avoid cracking.

After you finally retract the pads, remove them and, in their place, install the bleeding block. You can now start to remove your old brake line. At this point, you will need to cut the cable ties holding the line in place.

Now, remove your brake line from the caliper and the brake lever. A flare nut will significantly help you if the brake line goes directly into the caliper. You will. We need to find a small container to catch the brake fluid that comes out of the line.

Once the brake line is out, you can start to install the new one. But, first, you can align the new one to the old one and cut it to the correct size. 

Final Words

A person and his mountain bike at the top of a hill.

Brake Lines in your mountain bikes are vital to the rider and other cyclists to avoid accidents. They also help the rider to control their bike efficiently. The good thing about brake lines is that they are made of steel, so it might take some time before you change other brake lines. From my experience, the first brake lines were not quality, and thus they did not last long.

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However, authentic brake lines can last long and endure the harsh environment around them. However, be extra vigilant with brake lines and make sure that they are always in good condition. If you need to install new ones, you don’t need to call in a mechanic; you can consider it a DIY project and follow the instructions below.