The Kawasaki KLR650 uses DOT 4 brake fluid that should be flushed and bled every two years or whenever the brakes feel spongy, or if the brake system has been taken apart and rebuilt. Always use fresh brake fluid from a tightly sealed container.
SAFETY FIRST: Protective gloves and eyewear are recommended at this point.
Warning: Brake fluid is very caustic and can damage paint, chrome and plastic. Wipe up any spills immediately.
Front Brake Bleeding
Place the motorcycle on a stand.
Turn the handlebars until the top of the front master cylinder reservoir is level with the ground.
Remove the master cylinder reservoir cover screws using a #2 Phillips head screwdriver.
Remove the cap, plastic spacer plate and the rubber diaphragm. Clean and inspect the rubber diaphragm for tears or other damage. Replace as necessary.
Fill the reservoir with DOT 4 brake fluid from a tightly sealed container. When bleeding the front brakes a geyser of brake fluid may shoot up from the reservoir, so place the master cylinder reservoir lid on top of the master cylinder, but do not install the screws.
Pull off the rubber cap over the bleeder valve and crack open the bleeder valve on the brake caliper using a 10 mm wrench. The photo is not of the Kawasaki KLR650 but the procedure is the same. This valve is usually very tight so use a 6 point box end wrench or a 6 point socket and ratchet to prevent rounding off the head. Snug the bleeder valve down.
Place a length of 6 mm inside diameter hose on the bleeder valve and place the other end in a container.
Pump the front brake lever several times and hold the lever in. While holding the lever in, crack open the bleeder valve. The front brake lever will travel all the way to the throttle grip and brake fluid and/or air will come out of the bleeder valve. Tighten the bleeder valve before releasing the front brake lever. Pump the lever several times again and repeat the process. Be certain to raise the master cylinder reservoir lid occasionally to make sure the reservoir doesn’t run dry. Add more brake fluid as necessary. Continue this process until clean brake fluid comes out of the bleeder valve and there are no air bubbles. The front brake lever should feel firm.
Add DOT 4 brake fluid until it is at the top of the brake fluid inspection window above the lower line.
Collapse the rubber diaphragm accordion. Place it on top of the reservoir and the plastic spacer plate on top of it.
Place the reservoir lid in position, install the two screws and tighten them down securely.