Harley Davidson Sportster 1970-2003. Owner's Manual - page 5
6 Remove the reservoir cap and check the fluid
level. Do not allow the fluid level to drop below the lower mark during
the bleeding process.
7 Carefully pump the brake lever three or four times and hold it while
opening the caliper bleeder valve. When the valve is opened, brake fluid
will flow out of the caliper into the clear tubing and the lever will
move toward the handlebar.
8 Retighten the bleeder valve, then release the brake lever gradually.
Repeat the process until no air bubbles are visible in the brake fluid
leaving the caliper and the lever is firm when applied. Remember to add
fluid to the reservoir as the level drops. Use only new, clean brake
fluid of the recommended type. Never reuse the fluid lost during
bleeding.
9 Replace the reservoir cap, wipe up any spilled brake fluid and check
the entire system for leaks. Note: If bleeding is difficult, it may be
necessary to let the brake fluid in the system stabilize for a few hours
(it may be aerated). Repeat the bleeding procedure when the tiny bubbles
in the system have settled out.
10 If you’re working on a four-piston rear caliper, repeat the procedure
for the other bleed valve.
If it’s not possible to produce a firm feel to the lever or pedal, the
fluid may be aerated. Let the brake fluid in the system stabilize for a
few hours, then repeat the procedure when the tiny bubbles in the system
have settled out. Also check to make sure that there are no “high spots”
in the brake hose where air bubbles can become trapped - this will occur
most often in an incorrectly mounted hose union, but also can be caused
by bleeding the brakes while some of the brake system components are at
such an angle to encourage this. Reversing the angle or moving the
affected component around will normally dislodge any trapped air.
