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.
Inspect the rear brake fluid level by looking through the window in the brake reservoir protective cover. The rear brake fluid level should be at the UPPER mark. To add fluid remove the two Phillips head screws and remove the rear brake reservoir protector cover using a #3 Phillips head screwdriver.
Remove the master cylinder reservoir bracket.
Unscrew the cap and inspect the rubber diaphragm and the brake fluid.The brake fluid should be honey colored, if it is dark the brake fluid needs to be replaced.
If the brake fluid level is low, carefully pour DOT 4 brake fluid into the reservoir until the fluid level reaches the upper mark. .
Re-install the rear brake reservoir components in the reverse order of disassembly.