Bleeding the Brakes on a 2008 Kawasaki EX500 / Ninja 500
Shop parts for a 2008 Kawasaki EX500 - Ninja 500 Motorcycle.
The 2008 Kawasaki EX500 — the final year of the Ninja 500 — uses hydraulic disc brakes at both ends: a single front caliper fed by the handlebar master cylinder, and a rear caliper fed by a pedal-operated master cylinder. There is no ABS and no linked brake system on this machine, which is good news for the home mechanic. Each brake circuit is independent and self-contained, so you can bleed the front and rear separately, at your own pace, with nothing more exotic than a wrench, some clear tubing, and a bottle. This guide walks you through a full fluid flush and air removal on both circuits.
When a Bleed Is Due
The most obvious trigger is feel. If the front lever has gone soft or spongy, if it now comes back closer to the grip than it used to, or if the rear pedal feels vague and travels further before it bites, air has likely found its way into the system. A lever or pedal that slowly sinks while you hold steady pressure is another classic sign.
Look in the reservoir windows as well. Fresh fluid is nearly clear with a faint amber tint; fluid that has gone dark, cloudy, or murky has absorbed moisture and broken down. Brake fluid is hygroscopic, meaning it pulls water out of the air over time, and that water lowers the fluid's boiling point. Under hard or repeated braking, fluid that boils creates vapor, and vapor compresses — which is exactly how brake fade and a long lever appear on a mountain descent. For that reason many riders refresh the fluid on a regular interval even when nothing feels wrong.
You should also bleed after any work that opened the hydraulic system: new brake lines, a caliper rebuild or replacement, master cylinder service, or a reservoir that ran dry.
Tools and Supplies to Gather
- Fresh brake fluid of the type printed on the 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 on each caliper
- Clear tubing sized to fit snugly over the bleeder nipple
- A small catch bottle to hang the tubing into
- 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 solo job much less fiddly
Setting Up Safely
Get the bike upright and stable on a stand before you touch anything. For the front circuit, turn the handlebars so the reservoir on the bars sits level — an off-angle reservoir will spill the moment you crack the cap. The rear reservoir on the EX500 sits low on the right side of the bike, so check that it is level too.
Brake fluid attacks paint and many plastics on contact, so drape rags over the tank, the front fairing and instrument area, and the bodywork around the rear reservoir. If a drop does land on a painted surface, wipe it up immediately and rinse the area with water rather than letting it sit.
Bleeding the Front Brake
- Clean the reservoir cap and surrounding area so grit cannot fall in, then remove the cap and the diaphragm beneath it.
- Use the syringe or baster to draw most of the old fluid out of the reservoir. Leave a little at the bottom so you do not push air into the master cylinder.
- Top the reservoir up with fresh fluid from the sealed container.
- Slip the clear tubing over the front caliper bleeder and route the other end into the catch bottle, with the bottle positioned so the tubing runs upward away from the bleeder.
- Fit the box-end wrench onto the bleeder.
- Squeeze the front lever and hold it firmly.
- Open the bleeder about a quarter turn. Fluid and any trapped air will push out through the tubing. Watch the reservoir level as you do this.
- Close the bleeder before you release the lever. Releasing with the bleeder open draws air straight back in through the nipple.
- Release the lever slowly and repeat the squeeze-hold-open-close-release cycle. Keep topping the reservoir off between cycles so it never drops low enough to pull air into the master cylinder.
- Continue until the fluid coming through the tubing is clean and free of bubbles, then finish with the bleeder closed and the lever held.
If your bike has two front calipers, bleed them one at a time, completing one before moving to the other. A useful general habit is to start with the caliper farthest from the master cylinder in terms of hydraulic path, then work toward the closest.
Bleeding the Rear Brake
The rear circuit follows the same logic with a different input. Open the rear reservoir, remove most of the old fluid, and refill with fresh. Attach the tubing and wrench to the rear caliper bleeder, then press and hold the brake pedal instead of the lever. Open the bleeder a quarter turn, let fluid and air escape, close the bleeder, and only then release the pedal. Repeat, keeping the reservoir topped up, until the fluid runs clean and bubble-free. Because the rear reservoir is small, check its level after every few cycles rather than every cycle.
Finishing and Checking Your Work
With the final cycle complete, tighten each bleeder snugly with the box-end wrench — firm is enough; do not lean on it, because overtightening can damage the seat. Fill the reservoir to the level marking, reinstall the diaphragm and cap, and wipe away any fluid residue. Inspect the bleeder and the banjo fittings at the caliper and master cylinder for weeping.
Now test. The front lever and rear pedal should feel firm and consistent, and should hold pressure without slowly sinking. 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.
Troubleshooting and When to Stop
If the lever will not firm up after several rounds of bleeding, if it only firms after pumping, or if bubbles keep appearing no matter how long you work, something else is wrong — a worn master cylinder seal, a pinhole in a line, or a fitting drawing air. Fluid weeping from the master cylinder or caliper is a clear signal to stop and diagnose rather than keep bleeding. On this bike there is no ABS unit to complicate matters, but if you have replaced major components or simply cannot get a solid lever, hand it to a shop. Brakes are not the place to accept a maybe.
Related Shopping Categories
Shop Brake Fluid for a 2008 Kawasaki EX500 - Ninja 500 Motorcycle.
Shop Brake Lines for a 2008 Kawasaki EX500 - Ninja 500 Motorcycle.
Shop Brake Pads for a 2008 Kawasaki EX500 - Ninja 500 Motorcycle.
Shop Stands for a 2008 Kawasaki EX500 - Ninja 500 Motorcycle.
Shop Brake Tools for a 2008 Kawasaki EX500 - Ninja 500 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.