How To: Bleed Motorcycle Brakes

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Bleeding your brakes often is an easy way to avoid a mushy feeling and weak grab. In 10-15 minutes you can keep your brake systems feeling as strong as they did coming off the showroom floor. If you’ve ever bled the brakes on a car, the concept is the same and all you need is a few every-day supplies. A few things to remember: brake fluid is messy and can damage painted surfaces, so take precautions to avoid spillage. Also, some bikes (looking at you KTM) will still feel spongey after a handful of cycles. The trick is to be patient, use some of the air bubble tricks listed here, and keep bleeding.

Supplies Needed:

  • Brake Fluid
  • Shop Rags
  • Tools
    • 8mm or 10mm box end wrench
    • Screw driver
    • Impact driver (optional)
    • Fluid Catch Bottle (plastic water bottle and spare hose

    Steps:

    1. With the bike on the stand, remove the reservoir cap by loosening the two screws. Use an impact screwdriver if you have one, these screw heads often strip out.

    2. Pop the rubber cap off your bleeder down on the caliper, and slide on the wrench that will be used to crack open (unscrew) the bleeder nipple.

    3. With the wrench on the bleeder, install your fluid catch bottle. To make a catch bottle, drill a hole into the cap of a water bottle and feed hose into the hole. Use a bit of duct tape to hold the hose in the bottle.

    4. Pump the brake lever a number of times, on the last pump, continue to apply pressure while you crack the brake bleeder. Once you feel the lever loose pressure, tighten the bleeder. Repeat this process as needed. Helpful hint: this job is much easier with a friend who can either pump, or loosen the bleeder for you.

    5. As the fluid starts to bleed out of the system, replenish with new brake fluid (usually DOT 3 or 4. The top of the reservoir cap or manual should state which fluid). Be sure not to allow the fluid level to drop below the line hole, if this happens air will get sucked into the line and you will have to now bleed the air bubbles out.

    6. To get any remaining bubbles in the line out of your system, try back bleeding by pushing the caliper against the disk. You can also flick the brake like against the number plate and flick the brake line to let any remaining bubbles rise out the reservoir.

    7. Once the proper fill height is achieved with new fluid, reinstall the cap and tighten the screws. Place a shop rag under the master cylinder to catch any overflow fluid. Spray down with contact cleaner and remove any remaining fluid (brake fluid is very messy, so clean as well as possible.)