Bleeding your motorcycle brakes is super important. Over time, air can sneak into your brake lines, and you don’t want that. Unlike brake fluid, air is compressible, which means if there’s air in the system, you’ll end up with a spongy brake lever. You squeeze the lever expecting solid braking power, but instead, it feels soft and doesn’t engage as quickly or firmly as it should. That’s not the kind of surprise you want when you need to stop in a hurry.
Continue reading for our guide on how to bleed your motorcycle’s brakes. This guide is universal, meaning you can follow this guide no matter which bike you have. We will go over why and when to bleed the brakes, also when to change the fluid and the tools needed with a step by step guide.
Why do you need to bleed your motorcycle brakes?
Air in the braking system can alter how your brakes perform. It can get into the system in a few different ways. For example, maybe you’ve just replaced your brake fluid, and some air got trapped, or maybe the brake lines have a slight leak. Even something as simple as your bike being stored with the brake lever pulled in can let air seep in over time. Once it’s in there, it disrupts the hydraulic pressure, and your brakes can feel unreliable.
Bleeding the brakes is like giving your bike’s braking system a deep cleanse. You’re pushing out any trapped air and making sure that the system is filled with pure brake fluid, giving you a solid, consistent lever feel. Plus, it helps ensure that there’s no moisture or old fluid left in the lines, which can lead to corrosion or reduced braking performance.
It’s not a tough job, and doing it regularly, like every time you change your brake fluid, or if you notice any change in brake feel, keeps everything performing at its peak. It’s a small bit of maintenance that can make a huge difference in your bike’s stopping power and, ultimately, your safety on the road.
Why replace brake fluid
Think of brake fluid like the lifeblood of your braking system. Over time, it tends to absorb moisture from the air, a process called hygroscopicity. This is a fancy way of saying it pulls in water, even through microscopic pores in the brake lines and reservoir.
When this happens, a couple of things can go wrong. First, the boiling point of the brake fluid drops significantly. That’s a big deal because when you’re riding, especially if you’re braking hard or riding in hot conditions, your brakes can get pretty toasty. If the fluid boils, it turns into gas, which is compressible, unlike liquid. This can lead to a spongy brake feel or, in the worst case, complete brake failure. Not something you want happening when you’re carving through a twisty road, right?
Secondly, water in the system can cause corrosion inside the brake lines and callipers. This can lead to rust and pitting, which is like sandpaper inside your brake system. It wears things down faster and can cause seals to fail or pistons to seize. Once that happens, you’re looking at a lot more maintenance and potentially expensive repairs.
So, replacing your brake fluid isn’t just a matter of keeping everything clean and tidy, it’s crucial for your safety and for keeping your bike’s braking performance at its best. Most manufacturers recommend changing it every two years, but if you ride aggressively or in variable weather conditions, you might want to do it even more often. It’s a relatively simple and inexpensive job that can save you from some major headaches, or worse…down the road.
When to replace brake fluid
Manufacturers recommend every 2 years. Replacing your brake fluid should be part of your regular maintenance routine. But, just like with most things on a bike, it’s not a one-size-fits-all rule. There are some telltale signs that your brake fluid might be ready for a refresh, even if it’s ahead of schedule.
First off, if your brake lever or pedal starts to feel squishy or spongy, that’s a red flag. It’s a sign that your brake fluid might have absorbed too much moisture or that there’s air in the system, reducing its efficiency. Your brakes should feel firm and responsive, not like you’re squeezing a stress ball!
Another sign is if the fluid in the reservoir looks dark and murky instead of clear or a light amber colour. Over time, brake fluid can get contaminated with moisture and debris, which degrades its performance. If it looks like black coffee or tea, it’s definitely time to swap it out.
You might also notice reduced braking performance, like having to pull the lever or press the pedal harder to get the same stopping power. This could mean the boiling point of your fluid has dropped, possibly due to moisture contamination. This is especially noticeable during aggressive riding or in hot weather, where your brakes might feel fine at first but then start to fade or lose their bite.
Lastly, if it’s been more than two years or you can’t remember the last time you changed it, it’s a good idea to go ahead and replace it. Brake fluid maintenance isn’t just about preventing problems; it’s about keeping your brakes performing at their best so you’re always ready to stop on a dime when you need to.
So, if any of these signs sound familiar, or if it’s just been a while, grab some fresh fluid and give your bike the attention it deserves. It’s a quick job that can make a big difference in how safe and confident you feel out on the road!
Can I bleed the fluid on a bike with ABS?
Absolutely, you can bleed the brake fluid on a motorcycle with ABS! It’s a bit more involved than on a non-ABS bike, but totally doable with the right approach. The key is understanding that the ABS system adds an extra layer of complexity because it has its own internal channels and valves that can trap air or old fluid if you’re not careful.
When you bleed the brakes on an ABS-equipped bike, you’re essentially doing the same thing as you would on a standard system, pushing fresh fluid through the lines to get rid of any air bubbles and contaminated fluid. But, because of the ABS unit, you need to make sure that the fluid moves through both the standard brake lines and the ABS module.
Some bikes will require you to activate the ABS pump during the bleed process to ensure all the old fluid is flushed out of the system. You can do this by riding the bike and engaging the ABS, or by using a diagnostic tool that cycles the pump for you. It sounds more complicated than it is, but it’s just making sure the whole system gets a clean sweep.
If you’re doing it yourself, it’s a good idea to check the service manual for your specific bike because some manufacturers have different procedures for bleeding ABS brakes. And if you’re not feeling confident, taking it to a shop isn’t a bad idea—better to be safe, especially with something as critical as your brakes!
So yes, you can absolutely bleed the brakes on an ABS-equipped bike. Just take your time, follow the right steps, and you’ll keep that braking system in top shape, ready to give you smooth, controlled stops whenever you need them!
Tools needed
There isn’t actually much needed when it comes to bleeding your motorcycle brakes, even if it’s the first time you’re attempting to bleed the brakes you probably have most of the things you need.
- Brake fluid
Make sure it’s the right specification for your bike. As with other automotive fluids, brake fluids are graded to certain requirements which suit different braking systems.
Getting the right one is important as mixing brake fluids can cause compatibility issues due to the boiling points being different.
- Brake bleeder kit or hose
This is what you’ll use to drain the fluid from your bike.
- Wrench
Often 8mm or 10mm in diameter. Used to attach the hose to the bleeder valve on the brake calliper.
- Container
A simple plastic container to catch the brake fluid which is being drained from the system. Pro tip: make sure it’s a clear container so you can see the colour and how much you’re draining. Anything from an old milk bottle or drinks bottle would work. We said you’d probably have some of the things you’ll need!
- Cloths, paper towels or rags
To wipe up any mess or residue that may spill from the brake reservoir or the container.
How to bleed motorcycle brakes – Step by step
Prep the Bike and Tools:
Get your bike on a stand or level ground, ensuring it’s stable.
Remove the brake reservoir cap (on the handlebars for the front and near the rear brake lever for the back) and cover any painted areas around it with rags to protect from spills.
Top Off the Reservoir:
Fill the reservoir with fresh brake fluid. Don’t let it go empty during the process, or you’ll end up sucking air into the system, which is exactly what we’re trying to avoid. It’s not a massive issue if you do, but it’ll just prolong the whole process as you’ll have to bleed it more to get this air out the system.
Attach the Bleeder Hose:
Slip one end of your clear plastic tube onto the bleeder valve (usually located on the brake calliper) and put the other end into your container. This setup lets you see the fluid coming out and prevents air from getting sucked back in.
Pump the Brake Lever:
Pump the brake lever (or pedal if you’re doing the rear) a few times until you feel some resistance. Then, hold it down—this builds pressure in the line.
Open the Bleeder Valve:
While holding the brake lever down, use your wrench to crack open the bleeder valve just a little. You’ll see fluid and maybe some air bubbles coming through the tube. As soon as the lever or pedal bottoms out, close the bleeder valve before releasing the lever.
Repeat Until Bubble-Free:
Keep repeating the pump-hold-open-close sequence until you see no more bubbles in the fluid coming out. This could take a few cycles, depending on how much air is in the system.
Check the Reservoir:
Keep an eye on that reservoir! If it runs dry, you’ll suck air into the lines and have to start over. Top it off as needed.
Bleed Each Brake Calliper (if applicable):
If your bike has dual front discs, you’ll need to bleed each side separately. Same process: start with the calliper farthest from the master cylinder (usually the right side).
For ABS Systems:
If you’ve got ABS, make sure to follow any special instructions for your bike. Some systems require you to cycle the ABS pump during the process. Check your service manual or take a quick ride to engage the ABS before doing a final bleed.
Final Check:
Once you’re bubble-free and happy with the lever feel, top off the reservoir to the max line, put the cap back on securely, and clean up any spills.
Test It Out:
Roll the bike back and forth and give the brakes a few good squeezes to make sure everything feels solid. You want a firm lever with no sponginess.
And that’s it! Bleeding your brakes is all about patience. Take your time, and don’t rush it. You’ll know you’ve done it right when you’ve got a solid, responsive brake lever or pedal that gives you confidence on the road. Now get to pumping!
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