How To Bleed Mountain Bike Brakes?

Maintaining the brakes on your mountain bike is crucial for both performance and safety. When the brake pads wear down or the brake fluid becomes contaminated, your brakes may start to feel spongy or not work as effectively. Bleeding the brakes is a simple process that can help restore the performance of your mountain bike’s brake system.

In this post, we’ll go through the steps of how to bleed mountain bike brakes, including the tools and materials you’ll need, how to prepare your bike, and how to finish up. We’ll also cover some tips for maintaining your mountain bike brakes and troubleshooting common issues. Let’s get started!

Tools and Materials Needed:

Before you start bleeding your mountain bike brakes, you’ll need to gather a few tools and materials. Here’s what you’ll need:

  • A brake bleed kit: Most kits come with syringes, tubing, and brake fluid, and some may include a hose adapter or other tools. Make sure to get a kit that is compatible with your specific brake system.
  • Wrenches and/or Allen keys: Depending on your bike’s setup, you may need these to remove the brake caliper and/or rotor.
  • Rags or paper towels: These will come in handy for cleaning up spills and wiping down the brake components.
  • Glove: It’s a good idea to wear a glove to protect your hands from the brake fluid, which can be harmful if ingested or absorbed through the skin.
Preparing the Bike

Preparing the Bike:

Before you start bleeding the brakes, you’ll need to prepare your bike. Here’s what you’ll need to do:

  • Locate the brake bleed port: This is typically a small valve on the brake caliper or brake lever. Refer to your bike’s owner’s manual or the manufacturer’s instructions to find the correct location.
  • Remove the brake fluid reservoir cap: This will allow you to easily access the brake fluid and see the level as you bleed the brakes.
  • Remove the brake pads: In order to get to the brake bleed port, you’ll need to remove the brake pads from the caliper. This is usually done by pulling out the retaining pin and sliding the pads out.
  • Secure the bike: It’s best to have the bike on a stand or upside down while bleeding the brakes. This will allow gravity to help you remove all of the old brake fluid from the system.
Bleeding the Mountain Bike Brakes

Bleeding the Mountain Bike Brakes:

Now it’s time to actually bleed the brakes. Here’s what you’ll need to do:

  • Follow the manufacturer’s instructions: Each brake system is a little different, so it’s important to follow the specific instructions provided by the manufacturer. Make sure to pay attention to the order in which you bleed the brakes (front and rear, or left and right).
  • Purge all of the old brake fluid: The goal of bleeding the brakes is to remove all of the old, contaminated brake fluid from the system and replace it with fresh fluid. Follow the instructions for purging the system and replacing the brake fluid.
  • Be patient: Bleeding the brakes can be a bit time-consuming, so be patient and take your time. It’s important to do a thorough job to ensure the best performance from your brakes.

Finishing Up:

Once you’ve finished bleeding the brakes, there are a few more steps you’ll need to take:

  • Reinstall the brake pads: Make sure to properly align the brake pads and secure them in place with the retaining pin. Check for proper pad clearance
  • Test the brakes: Before you take your bike out for a ride, it’s important to test the brakes to make sure they are working properly. Slowly squeeze the brake lever and see how the brakes feel. If they feel spongy or not as responsive as they should be, you may need to make some adjustments.
  • Clean up any spills: Brake fluid can be corrosive, so it’s important to clean up any spills or splatters. Use a rag or paper towel to wipe down the brake components and dispose of the old brake fluid properly.
Maintenance and Troubleshooting

Maintenance and Troubleshooting:

To keep your mountain bike brakes in top condition, it’s important to perform regular maintenance. Here are a few tips:

  • Replace the brake pads: As the brake pads wear down, they will need to be replaced. This is typically a simple process that involves removing the old pads and installing new ones.
  • Check the brake fluid level: It’s a good idea to check the brake fluid level periodically to make sure it’s at the proper level. If the fluid is low, you may need to add more.
  • Clean the brake components: Over time, dirt and grime can build up on the brake components, which can affect the performance of the brakes. Use a rag or brush to clean off any debris.
If you run into any issues while bleeding your mountain bike brakes, here are a few common problems and their solutions:
  • Brakes feel spongy: If the brakes feel spongy or not as responsive as they should be, it could be due to air in the brake system. Bleed the brakes again, making sure to follow the manufacturer’s instructions for purging the air from the system.
  • Brake fluid leaks: If you notice brake fluid leaking from the brake system, it could be due to a faulty seal or hose. Check for any visible signs of damage and replace any damaged components as needed.
  • No brake fluid coming out: If you’re having trouble getting brake fluid to flow through the system, it could be due to a blockage. Check for any debris or clogs in the system and remove them as needed.

How to bleed MTB brakes


bleeding mountain bike brakes is a simple process that can help restore the performance of your brake system. By following the steps outlined above and performing regular maintenance, you can keep your brakes in top condition and enjoy a safer, more enjoyable ride.