Bleeding the Brakes on a 1988 Kawasaki EX500A
Shop parts for a 1988 Kawasaki EX500A Motorcycle.The 1988 Kawasaki EX500A uses a conventional hydraulic disc brake at the front wheel and another hydraulic disc brake at the rear wheel. It does not have ABS, and it does not use a linked or combined braking system. That makes it a straightforward bike to bleed at home: the front lever and rear pedal each operate their own hydraulic circuit, and each circuit has a caliper bleeder that lets you push old fluid and trapped air out. The job is still safety-critical, so work methodically, keep the reservoir from running dry, and test carefully before riding normally.
When a Bleed Is Needed — and Why It Matters
Bleed the EX500A brakes when the front lever feels spongy, when it pulls closer to the grip than it used to, when the rear pedal feels soft or travels farther than normal, or when the fluid in either reservoir looks dark, cloudy, or contaminated. A bleed is also required after any work that opens the hydraulic system, such as replacing a brake line, servicing a caliper, or repairing the master cylinder. Even without symptoms, brake fluid absorbs moisture from the air over time. That moisture lowers the fluid’s boiling point, which can cause brake fade under hard or repeated use. Many riders refresh brake fluid on a regular schedule as preventive maintenance, especially on an older bike like this EX500A where the fluid may have been in place for years.
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 snugly
- Clear tubing that fits tightly over the bleeder valve
- A small catch bottle for used fluid
- Rags or shop towels, plus water for rinsing spills
- A syringe or turkey baster for removing old fluid from the reservoir
- The correct driver for the reservoir cap screws
- Optional: a one-way check-valve bleeder or vacuum bleeder to make one-person bleeding easier
Brake fluid damages paint and many plastics on contact, so keep rags over the front reservoir area, the instrument cluster, and any painted bodywork below the master cylinder. Wipe up spills immediately and rinse the area with water. Do not use fluid from a container that has been open and sitting around; moisture contamination is exactly what you are trying to remove.
Preparation Before You Open the System
Support the EX500A securely upright on a stand so it cannot tip while you are working the lever or pedal. For the front brake, turn the handlebars until the front master cylinder reservoir sits level; otherwise fluid can spill as soon as you remove the cap. Cover the area around the reservoir with rags. For the rear brake, locate the rear master cylinder reservoir and make sure it is positioned so you can check and top off the fluid without introducing air. Clean around the reservoir cap and the bleeder valves before opening anything, so dirt does not fall into the system.
Step-by-Step Bleeding Procedure
- Remove the reservoir cap and diaphragm. Use the syringe or turkey baster to draw most of the old fluid out of the reservoir, but do not let the reservoir run completely dry. Leave enough fluid to cover the outlet at the bottom.
- Refill the reservoir with fresh fluid from the sealed container, up to the level marking. Keep the cap and diaphragm nearby but do not install them yet.
- Fit the clear tubing over 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.
- For the front brake, squeeze the lever several times to build pressure, then hold it firmly against the grip. For the rear brake, press and hold the pedal. Keep steady pressure on the lever or pedal.
- With pressure held, open the bleeder valve about a quarter turn with the box-end wrench. Fluid and air will flow through the tubing. Watch the reservoir level and stop before it drops low enough to draw air.
- Close the bleeder valve before releasing the lever or pedal. Releasing first can pull air back into the caliper. Then release the lever or pedal slowly.
- Top off the reservoir with fresh fluid. Repeat the squeeze-hold-open-close-release sequence until clean, fresh fluid comes through the tubing with no bubbles. Do not pump rapidly with the bleeder open; steady pressure and a controlled bleed work better.
- If your bike has more than one front caliper, bleed one caliper at a time and finish that caliper before moving to the next. As a general practice, start with the caliper farthest from its master cylinder, then move to the closer one.
- Repeat the same process for the rear brake using the rear pedal and rear caliper bleeder. Keep the rear reservoir topped off throughout.
- When the fluid runs clear and bubble-free at each caliper, close the bleeder snugly. Do not overtighten it; snug is enough to seal without damaging the valve seat.
Finishing, Checking, and Testing
Fill each reservoir to the correct level marking, then reinstall the diaphragm and cap. Wipe away any spilled fluid and rinse the area with water. Check the bleeder valves and the banjo fittings at the master cylinder and caliper for weeping or wetness. A dry fitting after several firm lever or pedal applications is what you want to see. Before riding, the front lever and rear pedal should feel firm and consistent, not spongy, and they should not slowly sink while you hold steady pressure. Spin each wheel to confirm the brake is not dragging. Then test at low speed in a safe area, such as an empty lot, before riding in traffic.
Troubleshooting and When to Stop
If the lever or pedal will not firm up after several bleeding attempts, if it firms only after rapid pumping, or if bubbles keep appearing no matter how long you bleed, stop and diagnose rather than continuing to pump fluid through. Persistent air usually means the reservoir ran low, a fitting is drawing air, or a seal is failing. Fluid leaking from the master cylinder or caliper also calls for inspection and repair before the bike is ridden. Because this EX500A has no ABS unit and no linked-brake plumbing, you do not have to deal with a dealer-only ABS bleed sequence or a linked-brake bleed order on this particular bike. If the brakes still feel wrong after a careful bleed, have a qualified shop inspect the system.
Related Shopping Categories
Shop Brake Fluid for a 1988 Kawasaki EX500A Motorcycle.
Shop Brake Lines for a 1988 Kawasaki EX500A Motorcycle.
Shop Brake Pads for a 1988 Kawasaki EX500A Motorcycle.
Shop Stands for a 1988 Kawasaki EX500A Motorcycle.
Shop Brake Tools for a 1988 Kawasaki EX500A 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.
