Having well-maintained brakes is essential to safety on the road. That means changing your brake fluid every one to two years or when you notice your brakes are getting mushy. Luckily, this process is something you can do yourself. It’s fairly easy, although there are certain things you need to look out for to ensure you do it correctly. To give you a hand, we’ve compiled this handy step-by-step guide with everything you need to know about how to change brake fluid motorcycle.
1. Look After Your Brake System
Before you change your brake fluid, take a look at your brake system to see if you need to repair or replace the following parts:
Brake pad springs
It’s important to do this now because the repair process may inadvertently allow air into the line, which can degrade the fluid it contains. Brake fluid is hygroscopic, which means it absorbs moisture easily. When it does so, the boiling point falls. The lower the boiling point, the less effective the fluid becomes. Because air is usually full of moisture, it’s important to keep brake fluid away from the air as much as possible. The purpose of the bleeding process is to get rid of air bubbles and degraded fluid, so if you do repairs after a motorcycle brake fluid change, you may be undoing all your hard work.
2. Get the Right Brake Fluid
How do you know which is the best motorcycle brake fluid? The answer is that is varies depending on your bike. There are three types of brake fluid:
DOT3 and DOT4 are generally used in motorcycles. DOT5 is very rarely used because it’s silicone-based. To find out which type your motorcycle needs, consult your owner’s manual or check the master cylinder reservoir cap – most have the type printed underneath.
3. Gather Equipment
For this process, you’ll need a few pieces of equipment:
A wrench or other tool to loosen the bleeder bolt
A container for fluid collection
Your container doesn’t need to be anything special. You can even use an empty soda can or water bottle, as long as you’re able to make sure it doesn’t tip over during the process.
4. Prepare Your Bike
Brake fluid is highly corrosive, which means it can do a number on your bike’s paint job. To protect your motorcycle’s glossy finish, cover it with an old blanket or towel. When you’re done, just wash or throw away the covering.
5. Access Master Cylinder Reservoir
Locate your master cylinder reservoir – it’s usually up near your handlebars – and unscrew the cap. While you’re more than welcome to set it aside, we recommend letting the cap sit on top of the reservoir in between adding fluid. Bleeding the brakes usually causes air to move through the line, which may result in air bubbles coming to the surface of the reservoir and causing splatter. Your bike should be fine if you’ve protected it with a covering, but we believe the less mess you have to deal with, the better.
6. Attach Collecting Container
Set your container on a flat surface and put one end of the tubing into it. Take the rubber cap off the bleeder bolt and set it somewhere safe so you don’t lose it. That little piece keeps air from getting into the line, so it’s essential you put it back when you’re finished. Connect the other end of the tubing to the bleeder bolt.
7. Bleed Brake Fluid
These next steps describe how to add brake fluid to a motorcycle without allowing air into the line, so be sure to follow them carefully.
First, make sure the master cylinder reservoir is full, but not overly so. You can top it off if you need to. This ensures that you don’t accidently pull in air when pumping the brakes.
Next, pump the brake lever to build up pressure. After a few pumps, hold it. While holding the lever, use your motorcycle brake bleeder tool to open the bolt and allow the fluid to drain. You’ll feel the pressure go down and may see air bubbles in the line.
Before the master cylinder empties, tighten the bleeder bolt. Once it’s secure, you can let go of the brake lever.
Refill the master cylinder. Repeat this process until there are no more air bubbles and the brake lever resistance becomes noticeably firmer. When you’re done, remember to fully close the master cylinder reservoir cap.
8. Clean Up
Now that you’re finished, it’s time to clean up. Brake fluid is considered toxic waste, so it must be disposed of responsibly. The laws outlining how toxic waste needs to be handled vary by state and city, so be sure to consult local ordinances before deciding what to do. The most common acceptable methods of disposal are the following:
Dropping it off at a waste processing plant that can handle toxic waste
Dropping it off at a recycling plant that can process automotive fluids
Dropping it off at an auto parts store that participates in a collection program
Pouring it in kitty litter and allowing it to evaporate
If you have fresh brake fluid left, you can safely store it in your garage. However, since it’s been exposed to air, it’s already begun to degrade, which mean its shelf life is drastically shortened. You should keep it no longer than six months – any more than that, and it won’t work effectively.
9. Alternative Option
Some people prefer changing brake fluid without bleeding. To do this, you need two syringes, fresh brake fluid and tubing.
Connect the tubing to the bleeder bolt as before. Fill the syringe with fluid. Open the bleeder bolt and inject new brake fluid into the tubing. Air bubbles and old fluid should move into the master cylinder. Use the other syringe to remove the old brake fluid while making sure not to empty the cylinder completely.
Motorcycle brake bleeding is a vital step in bike maintenance and road safety. Even if you don’t ride as often as you’d like, make sure you’re changing your brake fluid as recommended to keep your motorcycle in prime condition.