Bleeding air out of Harley Davidson front brakes is not always simple, even for the experienced, as the master cylinder reverses the fluid flow when the lever is released which sucks air back into the system.
I have tried many different methods, including, suction pumps, pressure pumps, gravity bleeding, and 'two people' bleeding but have only achieved success by doing as follows:

Danger! Do Not Get Brake Fluid On Paintwork! Cover as necessary!

Remove brake pipe banjo fitting bolt(s) and remove caliper(s).
Remove brake master cylinder/lever and brake hose assembly and attach to a second handlebar that you can rest on the ground or bench, (keep reservoir as level as possible).
Thoroughly wipe banjo fitting(s) and bolt(s), then loop the brake lines so that the brake line banjo fitting(s) are in the master cylinder reservoir, and submerge them in the brake fluid completely.
Slowly squeeze and release the brake lever until no air bubbles can be seen.
Remove the bleeder nipple(s) from the caliper(s) and whilst holding the caliper in a manner that has the fitting holes at the highest point, pour brake fluid into the caliper(s) at each threaded hole, until no more fluid will go in.
Refit the bleeder nipples(s) finger tight.
Attach brake line(s) to caliper(s), and tighten snugly.
Place a solid spacer in between the brake pads (a screwdriver, an old brake pad etc.) so that the pistons won't pop out.
Attach a 150mm to 200mm length of windshield washer hose to the bleeder nipple(s) and 3/4 fill hose(s) with brake fluid.
Fill brake fluid reservoir, squeeze lever and hold, loosen bleeder nipple(s).
Re-tighten bleeder nipple(s) and slowly release lever.
Open bleeder nipple(s) and observe if fluid is sucked back into caliper, keep washer hoses at least half full at all times.
Repeat the above procedure a number of times until no air is coming out when squeezing lever, and no fluid is sucking back into caliper(s) when releasing lever.
Attach master cylinder, caliper(s), and lines back to bike as a unit.
Loosen banjo bolt at master cylinder whilst squeezing lever, lock bolt when lever is pulled in, then slowly release.
Repeat process at banjo bolt on the caliper(s).
Repeat bleed process at each bleeder nipple if necessary.
Brake lever should be hard with a 3mm to 4mm gap between front inner vertical edge of brake of lever, and lever housing.
Clean all spilled brake fluid by rinsing with hot water, then wash with soapy water!
Good Luck!