How to Bleed Harley Dual Disk Brakes

Air in the brake lines of Harley-Davidson motorcycle dual disk brakes diminishes the efficiency of the brakes and can even render them inoperable if the problem is not addressed. A sign that air is trapped in the brake line is a feeling of play, or a spongy feeling, when the hand brake levers are squeezed. If air is trapped in the line, it has to be removed. Removing the air from the brake lines will take about an hour. An assistant is required for this job.

Instructions

1

Park the Harley on a flat and level surface.

2

Clean the master cylinder with an old shop rag. Remove the rubber bleeder valve cap, or boot. Slip one end of the plastic tubing over the bleeder valve and the other end in the drip pan.

3

Remove the master cylinder cover retaining screws with a Phillips screwdriver. Remove the cylinder cover and set it and the screws aside.

4

Pour brake fluid to fill the master cylinder to the full level and then have assistant squeeze the brakes a few times to build up pressure in the line.

5

Turn the bleeder valve a quarter turn with an open-end wrench. The size of the wrench will vary with Harley different models, but most use a 5/16 wrench.

6

Watch the brake fluid draining through the clear hose as the assistant squeezes the brake. Look for air bubbles. Close the valve once the fluid stops draining, by tightening it to the right with the wrench.

7

Refill the master cylinder with brake fluid, open the valve and have assistant squeeze the brake again. Continue this process until all the air bubbles have been removed from the fluid. Once they have, close the valve with the wrench, remove the plastic tubing and then put the rubber bleeder valve cover back on.

8

Fill the master cylinder to the full level with brake fluid and then replace the cover and retaining screws with the screwdriver. Squeeze the brakes a few times to make sure they feel tight.