How To Bleed 1989 Kawasaki EX250 - Ninja 250 Motorcycle Brakes

Bleeding the Brakes on a 1989 Kawasaki EX250 Ninja 250

Why and When the EX250 Needs a Brake Bleed

The 1989 Kawasaki EX250 Ninja 250 uses hydraulic disc brakes at both ends, so the front lever and the rear pedal each push fluid through a master cylinder, line, and caliper. That makes both systems serviceable with the same basic bleeding process. This bike does not have ABS or linked brakes, so you are dealing with two separate hydraulic circuits rather than a complex power-assisted or combined setup.

Bleeding is part fluid refresh and part air removal. Brake fluid absorbs moisture from the air over time, which lowers its boiling point and can make the brakes fade during hard or repeated use. Even if the bike still stops, dark or cloudy fluid in the reservoir is a sign that fresh fluid is overdue. A spongy lever, a pedal that feels soft, a lever that pulls closer to the grip than it used to, or a brake that firms up only after a few quick squeezes all point to air in the system. Bleeding is also required after any work that opened the hydraulic circuit, such as new brake lines, caliper service, or master cylinder work.

Tools and Supplies to Have Ready

• Fresh brake fluid of the type marked on the master cylinder reservoir cap, from a sealed container
• A box-end wrench that fits the bleeder valve
• A length of clear tubing that fits snugly over the bleeder
• A catch bottle for old fluid
• Rags or shop towels
• A syringe or turkey baster for removing old fluid from the reservoir
• A screwdriver or driver that fits the reservoir cap screws

A one-way check-valve bleeder or a vacuum bleeder can make the job easier when you are working alone, but the manual lever-and-bleeder method works fine if you have a helper or a way to hold pressure while you open the valve.

Preparing the Bike and Protecting the Finish

Support the EX250 securely upright on a stand so the reservoirs sit in their normal working attitude. Turn the handlebars so the front reservoir is level before you open it. Cover painted surfaces, plastic bodywork, and the instrument area with rags, because most brake fluids damage paint and plastic on contact. If a spill happens, wipe it up immediately and rinse the area with water. Keep the reservoir cap and diaphragm clean and set them aside where they will not pick up grit.

Step-by-Step Bleeding Procedure

1. Open the reservoir you are working on and use the syringe or turkey baster to remove most of the old fluid. Do not let the reservoir run dry.
2. Refill the reservoir with fresh fluid of the type marked on the cap, leaving room for the diaphragm and cap to be reinstalled later.
3. Attach the clear tubing to the caliper bleeder valve and route the other end into the catch bottle. Make sure the tubing fits snugly so air cannot be drawn in around it.
4. For the front brake, squeeze and hold the lever. For the rear brake, press and hold the pedal. Keep steady pressure on it.
5. Open the bleeder about a quarter turn and let fluid and air flow out through the tube. Watch the tube, not just the reservoir.
6. Close the bleeder before you release the lever or pedal. Releasing first can pull air back into the caliper.
7. Repeat the squeeze-hold-open-close-release cycle until fresh, clean fluid comes through the tube with no bubbles.
8. Keep topping off the reservoir throughout the process. If it runs low enough to draw air, you will have to start over on that circuit.
9. Work on one caliper at a time. If a system has more than one caliper, bleed each one separately and start with the caliper farthest from the master cylinder.
10. Finish the front circuit before moving to the rear, or the rear before returning to the front. Treat them as separate jobs so you do not mix up which reservoir is being watched.

Finishing the Job Correctly

When the fluid runs clean and bubble-free, tighten the bleeder snugly without overtightening it. Fill the reservoir to the correct level marking, reinstall the diaphragm and cap, and clean any spilled fluid from the caliper, line, and reservoir area. Check for leaks at the bleeder and at the banjo fittings. A small weep at the bleeder usually means it is not snug enough; a leak at a banjo fitting means that connection needs attention before the bike is ridden.

Testing Before You Ride

The front lever and rear pedal should feel firm and consistent, not spongy, and they should not slowly sink under steady pressure. Spin each wheel to confirm the brakes are not dragging. Test the brakes at low speed in a safe area before riding normally. If the lever or pedal feels different from one stop to the next, stop and investigate rather than assuming it will improve on the road.

Troubleshooting and When to See a Shop

If the lever or pedal will not firm up after several bleeding attempts, if it firms up only after pumping, if bubbles keep appearing, or if fluid is leaking from the master cylinder or caliper, the problem is beyond a simple bleed. Because this 1989 EX250 has no ABS or linked brakes, the usual home-bleed limits are simpler, but a brake that will not hold pressure still needs diagnosis. On a bike with ABS or linked brakes, air trapped in the ABS unit or a mistake in the required sequence is a reason to stop and let a shop handle it. For this Ninja 250, a clean, firm, leak-free system with fresh fluid is the goal, and anything short of that should be corrected before the bike is ridden.

Related Shopping Categories

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Shop Brake Tools for a 1989 Kawasaki EX250 - Ninja 250 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.