Bleeding the Brakes on a 2014 Kawasaki Ninja 300
Shop parts for a 2014 Kawasaki EX300 - Ninja 300 Motorcycle.
Know Your Ninja 300's Brake Layout First
The 2014 Kawasaki EX300 — the Ninja 300 — uses hydraulic disc brakes at both ends. A front caliper is fed by the lever-mounted master cylinder on the handlebar, and a rear caliper is fed by a pedal-driven master cylinder low on the right side of the bike. The two circuits are completely independent, so each one gets bled on its own, and a problem with one tells you nothing about the other.
Kawasaki sold the 2014 Ninja 300 in both ABS and non-ABS forms. If your bike carries the ABS badge, a hydraulic unit sits between the master cylinders and the calipers. A routine fluid flush through the caliper bleeders works the same way on either version. What changes is the failure case: if air has entered the ABS unit itself — because the reservoir ran dry, a line was opened, or the unit was removed — the bike needs a dealer-level procedure with the right diagnostic tool. This model does not use a linked or combined braking system, so the front lever operates only the front brake and the rear pedal operates only the rear.
How to Tell the Brakes Need Bleeding
The most common tip-off is feel. A lever that has gone spongy, or that now pulls noticeably closer to the grip than it used to, usually means air is in the system or the fluid has absorbed enough moisture to compress differently under load. The rear pedal can go soft in the same way. Pull the reservoir cap and look at the fluid: fresh brake fluid is clear and pale, while fluid that has been in service for a few seasons turns dark, cloudy, or tea-colored.
Bleeding is also mandatory after any work that opened the hydraulic circuit — new brake lines, a caliper rebuild or replacement, or master cylinder service. Beyond symptoms, brake fluid is hygroscopic, meaning it pulls moisture out of the air over time. That moisture lowers the fluid's boiling point, and a boiling fluid creates gas bubbles that cause the lever to fade toward the grip during hard, repeated braking. Many riders simply refresh the fluid on a regular interval rather than waiting for a symptom to appear.
Tools and Supplies to Gather
- Fresh brake fluid of the type printed on your master cylinder reservoir cap, from a sealed container — once a container is opened, it starts absorbing moisture, so use new stock
- A box-end wrench that fits the bleeder valve snugly
- A length of clear tubing that fits tightly over the bleeder nipple
- A small catch bottle for the old fluid
- Rags or shop towels, plus a syringe or turkey baster for pulling old fluid out of the reservoir
- The correct driver for the reservoir cap screws
- Optional: a one-way check-valve bleeder or a vacuum bleeder, both of which make a one-person job much easier
Setting Up Before You Open Anything
Get the bike secure and upright on a stand so it cannot tip while you are working the lever. For the front circuit, turn the handlebars until the reservoir on the bar sits level — a tilted reservoir lets fluid spill the moment the cap comes off. Drape rags over the tank or bodywork, the instrument cluster, and any painted or plastic surface near the reservoir and caliper. Brake fluid attacks paint and many plastics on contact, so wipe up any drip immediately and rinse the area with water if it reaches a finished surface.
Bleeding the Front Brake
- Remove the reservoir cap and diaphragm, then use the syringe or baster to draw most of the old fluid out of the reservoir. Leave a little in the bottom so you do not push air into the master cylinder.
- Refill with fresh fluid to a safe working level and set the cap loosely back on to keep debris out.
- Slip the clear tubing over the front bleeder valve and route the other end into the catch bottle, with the bottle positioned so the tubing runs upward away from the bleeder.
- Slowly squeeze the front lever and hold it. With the lever held, open the bleeder about a quarter turn and let the fluid and any trapped air escape through the tube.
- Close the bleeder fully before you release the lever. Releasing with the bleeder open draws air straight back into the caliper, which is the single most common way this job goes wrong.
- Repeat the squeeze–hold–open–close–release cycle, checking the reservoir level every few strokes and topping it off so it never runs low enough to pull air in.
- Keep going until the fluid coming through the tubing is clean and free of bubbles, then finish with the lever held and the bleeder closed.
If your bike has a second front caliper, bleed each one in turn, starting with the caliper farthest from the master cylinder and finishing with the closest.
Bleeding the Rear Brake
- Open the rear reservoir, remove most of the old fluid, and top it up with fresh fluid.
- Fit the clear tubing over the rear bleeder and into the catch bottle.
- Press and hold the brake pedal, crack the bleeder a quarter turn, then close it before releasing the pedal.
- Repeat, watching the reservoir level, until the fluid runs clean and bubble-free.
Finishing the Job
Tighten each bleeder snugly with the box-end wrench — firm enough to seal, but never so tight that you risk damaging the caliper threads. Fill the reservoir to the level marking on the body, reinstall the diaphragm and cap, and wipe down every surface you touched. Then inspect the bleeder valves and the banjo fittings at the caliper and master cylinder for weeping fluid; a wet fitting means something is not seated properly.
Test Before You Ride
Both the lever and the pedal should feel firm and consistent, and neither should slowly sink while you hold steady pressure. Spin each wheel by hand to confirm the brakes are not dragging. Then, in a safe open area, test the brakes at low speed before riding normally.
When to Stop and Take It to a Shop
If the lever will not firm up after several honest bleeding attempts, if it only firms up after pumping, or if bubbles keep appearing no matter how long you bleed, stop and have the bike inspected. The same applies to fluid leaking from the master cylinder or caliper, and to any ABS-equipped bike where the reservoir ran dry or a line was opened — that air may be trapped in the ABS unit and needs the proper procedure to clear.
Related Shopping Categories
Shop Brake Fluid for a 2014 Kawasaki EX300 - Ninja 300 Motorcycle.
Shop Brake Lines for a 2014 Kawasaki EX300 - Ninja 300 Motorcycle.
Shop Brake Pads for a 2014 Kawasaki EX300 - Ninja 300 Motorcycle.
Shop Stands for a 2014 Kawasaki EX300 - Ninja 300 Motorcycle.
Shop Brake Tools for a 2014 Kawasaki EX300 - Ninja 300 Motorcycle.
Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.