While you may consider this task to be complex, with a little knowledge and the right tools this maintenance item really isn’t that hard.
The primary tool you will want to invest into is a brake bleeding vacuum tool. This tool makes the job quick, clean, and easy. Along with this you will need a box end wrench that matches the size of the bleeding nipple on your motorcycle. For mine this was 10mm for the brakes and 8mm for the clutch. Of course you will need the appropriate brake fluid along with a container to hold the old fluid. Finally some rags and paper towels come in handy to catch any drips or dribbles.
Step 1: Refer to your Service Manual
My owner’s manual included where the fluid reservoirs are located on my motorcycle and how to fill them to the correct levels. It also includes the grade of brake fluid to use, which is a very important detail. You may also find the service interval for fluid replacement which is usually ever two years.
For my motorcycle, the same grade (DOT 4) and type (brake fluid) is used in brakes and clutch systems. Make sure it’s a newly opened container of fluid. My motorcycle had one reservoir on the right handle bar for the front brakes. The rear brake reservoir was located under a body panel on the right side of the bike (many will have it on the left handle bar). The clutch reservoir was located under a body panel on the left side of the bike. I had to remove several body panels to get access to all the locations but the steps were all listed in the owner’s manual.
The service manual included how many bleeding nipples there are and where they are located. It also included the specific order I needed to connect to each one of them. My motorcycle had four nipples for brakes and one for the clutch. One was on the left front brake caliper, two on the right front brake caliper (one is linked to the rear brake), and one on the rear brake caliper. Further, it stated that the order should be front brake system, then the front for the rear brake system and finally the rear brake. Since there were two on the front system but it didn’t list the order, I searched online and found that the preference for the front is the left and then the right.
The amount of new brake fluid will depend on your motorcycle, for me since I was also doing my clutch; I picked up the larger quart container. You will also want to have a large container to put the old fluid into as the vacuum tool will get filled up several times during this process. Make sure you have plenty of rags/paper towels around also, while generally it’s not too messy, even a drop of brake fluid on a painted body part can cause damage, so laying down some protection before you do work will be well worth it.