How To Bleed 2022 Kawasaki EX400 - Ninja 400 Motorcycle Brakes

Bleeding the Front and Rear Brakes on a 2022 Kawasaki EX400 Ninja 400

The 2022 Kawasaki EX400 Ninja 400 uses hydraulic disc brakes at both ends, so the front and rear systems can each collect air and old fluid over time. The front brake is operated by the lever and the rear by the pedal, and the EX400 is not a linked-brake model, so you can treat the two circuits separately. Some EX400s are equipped with ABS. On an ABS bike, a normal bleed through the caliper bleeders is generally used to refresh fluid, but if air has entered the ABS unit itself—for example, after the reservoir ran dry or the ABS unit or lines were disconnected—the bike may need a dealer-level procedure or diagnostic tool. This guide walks through a careful home bleed for the 2022 Ninja 400, including setup, the bleeding sequence, and the checks that confirm the job is complete.

When the EX400 Needs a Brake Bleed

Bleeding is due when the front lever or rear pedal feels spongy, when the lever pulls closer to the grip than it used to, or when the fluid in either reservoir looks dark or cloudy. It is also necessary after any work that opened the hydraulic system, such as installing new brake lines, servicing a caliper, or working on the master cylinder. Even without symptoms, brake fluid absorbs moisture over time, which lowers its boiling point and can contribute to brake fade under hard use, so many riders refresh it on a regular schedule. If you are unsure when the fluid was last changed, a bleed is a sensible starting point.

Tools and Supplies to Gather First

• 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 used fluid
• Rags or shop towels
• A syringe or turkey baster for removing old fluid from the reservoir
• A screwdriver that fits the reservoir cap screws
• Optional: a one-way check-valve bleeder or vacuum bleeder to make one-person bleeding easier

Use only fresh fluid from a sealed container, and do not reuse fluid that has been sitting open or drained from the system. Brake fluid damages paint and plastic on contact, so keep rags close and wipe up any spill immediately.

Setting Up the Ninja 400 Safely

Support the bike securely upright on a stand so it cannot tip while you work. For the front circuit, turn the handlebars so the front reservoir sits level before you open it. Cover painted surfaces, plastics, and the instrument area with rags, because drips are easy to create and hard to undo. If fluid does reach a painted or plastic surface, wipe it up immediately and rinse the area with water. Work in a well-ventilated area and keep the reservoir cap and diaphragm clean once removed.

Step-by-Step Bleeding Procedure

1. Open the reservoir for the circuit you are bleeding and remove most of the old fluid with a syringe or turkey baster. 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 later.
3. Attach the clear tubing to the 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. Start with the caliper farthest from the master cylinder in that circuit. If your bike has more than one front caliper, bleed each one in turn.
5. Squeeze and hold the front lever, or press and hold the rear pedal, to build pressure.
6. Open the bleeder about a quarter turn and let fluid and air escape through the tube.
7. Close the bleeder before releasing the lever or pedal. Releasing first can draw air back into the system.
8. Repeat the squeeze-hold-open-close-release sequence until fresh, clean, bubble-free fluid comes through the tube.
9. Keep topping off the reservoir throughout the job so it never runs low enough to draw air into the master cylinder.
10. When the front circuit is complete, repeat the same process for the rear circuit if needed, using the rear pedal and rear reservoir.

Finishing Up and Checking for Leaks

When clean fluid runs through with no bubbles, tighten the bleeder snugly without overtightening. Fill the reservoir to the correct level marking, reinstall the diaphragm and cap, and clean any spilled fluid from the bike. Check the bleeder and the banjo fittings for weeping or drips. A dry fitting after several lever or pedal applications is a good sign; a wet fitting needs attention before the bike is ridden.

Testing Before Normal Riding

The lever and 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 pull to the next, or if either slowly loses firmness, stop and investigate before trusting the bike on the road.

Troubleshooting and When to Visit a Shop

A lever that will not firm up after several bleeding attempts, a lever that firms up only after pumping, persistent air bubbles, or fluid leaking from the master cylinder or caliper are signs that the job is not complete. If the reservoir ran dry, if the ABS unit or its lines were disconnected, or if you are unsure whether air entered the ABS system, the bike should go to a shop for the correct procedure. The same applies if you are not confident following the required sequence on a system with additional bleed points. The EX400 is not linked, so linked-brake sequencing is not a concern here, but ABS air is still a reason to stop and seek professional help.

Related Shopping Categories

Shop Brake Fluid for a 2022 Kawasaki EX400 - Ninja 400 Motorcycle.

Shop Brake Lines for a 2022 Kawasaki EX400 - Ninja 400 Motorcycle.

Shop Brake Pads for a 2022 Kawasaki EX400 - Ninja 400 Motorcycle.

Shop Stands for a 2022 Kawasaki EX400 - Ninja 400 Motorcycle.

Shop Brake Tools for a 2022 Kawasaki EX400 - Ninja 400 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.