As a motorcycle rider, if you have a penchant for riding ATVs, bikes, or wheeled Powersports machines, you will eventually have to bleed your brakes. This is a part of your regular motorcycle maintenance routine that the user manual suggests you perform once or twice a year.
Your bike’s brake fluid must be replaced at regular intervals because it degrades with use and over time. Brake fluid, which is hygroscopic, absorbs water, which means that your motorcycle’s brake system might not work as well as it did when you first bought the bike. The absorbed water reduces the boiling point of the brake fluid and can lead to a spongy feeling when braking.
Bleeding your brakes is an important procedure that can help improve your motorcycle’s performance considerably. It doesn’t directly impact your motorcycle’s gas tank, but it is crucial to prevent the brake fluid from coming into contact with painted surfaces, including the gas tank, as it can damage the paint.
Consequences of Not Bleeding Motorcycle Brakes
If the motorcycle’s brake fluid doesn’t get replaced and is allowed to degrade due to old age, it can affect your braking performance. You might also experience poor control over your bike, which is never good when on bumpy roads or when riding at high speeds.
Brake fluids absorb water from the air, which can lead to corrosion on the metal and rubber components of your bike’s braking system, including the brake line, master cylinder, rubber hose, hydraulic cylinder piston, etc. This can hamper the performance of your brakes drastically, possibly leading to failure when you need them the most.
Bleeding your brakes does require special tools and equipment, which most owners only use during emergencies or if their bikes malfunction due to some other reason. However, despite its perceived difficulty, this process is straightforward if you have the right tools and follow a simple set of instructions.
Steps to Bleed Your Motorcycle Brakes
A Step by Step Guide to Bleeding Motorcycle Brakes:
- Remove the Diaphragm and Cap
Before you start flushing fluid or removing bolts, take some time to wipe your brake lines, reservoir, and calipers with a cloth to remove any dirt or debris on the surface of these components.
Remove the brake fluid cap and remove the rubber diaphragm (found in most motorcycles). Always inspect the motorcycle for the fluid level.
There are several different types of brake designs on modern motorcycles, but usually, there is only one rubber diaphragm that covers the top portion of your reservoir. Motorcycles that have built-in reservoirs do not usually come with this component.
- Ready the Caliper’s Bleed Nipple
Most motorcycle brakes have their own bleed nipples. You will need to pry off the aluminium caps (if any) over the brake fluid nipples on your brake calipers, using a screwdriver.
Pump the brake lever a few times to push any air out of it.
Allow the lever to slide back and close the bolt of the bleeder. Keep an eye on the level of fluid in your reservoir because it must not drop too low.
- Top Up The Reservoir
This step should be repeated for each brake system if your motorcycle has separate front and rear brake systems.
It is very important to always top up the reservoir after bleeding each system since it might lose fluid while you flush out old and contaminated brake fluid from within the lines and caliper.
Refill it with some new fluid until you can see fresh clear liquid on the hose.
Keep adding fluid until it reaches the brim of the reservoir, but take care not to overfill.
Now, take a piece of cloth and clean off any dirt from around your brake calipers, as well as from the bleed nipples on each caliper.
- Tighten Bleeder Bolt and Clean Up
Now, it’s time to tighten the bleeder bolt. Firmly close this bolt, taking care not to overtighten it. Lastly, replace the rubber diaphragm on top of your master cylinder’s reservoir and put the cap back on.
You can now go ahead and test out your brakes by applying pressure to your brake lever and stopping at the first sign of any resistance.
If you notice your brakes feeling spongy or completely unresponsive, then repeat these steps until you can feel the difference in performance. It usually takes about four separate bleeding sessions to start noticing improvements after completing this procedure correctly.
Special Considerations for Bleeding Motorcycle Brakes
While the steps provided above are a generally accepted guide for bleeding motorcycle brakes, it’s important to bear in mind that the specifics of this procedure can differ depending on the make and model of your motorcycle. Therefore, you should always consult your motorcycle’s owner’s manual for instructions tailored specifically to your vehicle. The manual will typically provide detailed instructions on maintenance procedures, including bleeding the brakes, and can provide valuable information about the specific requirements of your motorcycle.
Moreover, the exact tools and equipment required for this task may vary. The typical set of tools includes a wrench, a brake bleeder kit, and new brake fluid, but your manual may specify additional or different tools. Ensure you have all the necessary equipment before starting the procedure.
Remember that while many motorcycle riders are comfortable performing this maintenance task, it may not be the case for everyone. If you’re unsure about any step in the process, or if you’re not comfortable working with your bike’s brake system, it’s always a good idea to seek help from a professional mechanic. Brake systems are a critical safety feature on any vehicle, and any maintenance or repair work must be done correctly to ensure the safety of the rider.
In conclusion, while this guide provides a general overview of how to bleed your motorcycle brakes, always refer to your specific motorcycle’s owner manual and consider consulting a professional mechanic for personalized advice. This way, you can be confident that you’re maintaining your motorcycle’s brake system properly and safely.
While bleeding your motorcycle brake fluid is a procedure that can be done by yourself, it’s best done by a qualified mechanic to ensure that it’s completed correctly and safely. The above steps can guide you through the process, should you choose to do it yourself.
Bleeding your brakes can help improve your braking ability considerably, and also allows you to get the most out of your brakes and brake fluid.