How to Bleed the Brakes on a 2006 Honda ST1300

Shop parts for a 2006 Honda ST1300 Motorcycle.

The ST1300 is a long-legged sport-tourer that carries a lot of speed and a lot of weight, so the brake system deserves more respect than the average weekend wrenching job. Before you crack a bleeder open, it helps to understand exactly what you are working on, because the 2006 ST1300 is not a simple one-lever-one-caliper motorcycle.

Understand the System Before You Touch It

This motorcycle uses hydraulic disc brakes at both ends, so both the front and the rear are bled with fluid. It also came from Honda with anti-lock braking and a combined braking system, where the front lever also applies some rear braking force and the rear pedal applies some front braking force. That combined layout means there are bleed points beyond the calipers themselves, and those points have to be opened in a specific order for a complete flush.

What that means practically: refreshing fluid through the caliper bleeders is a reasonable home job and will improve lever feel, but a full system flush that includes the combined-brake hardware is a different animal. If you are not confident about the sequence, hand that part to a shop. And if the reservoir has ever run dry, or the ABS unit or its lines have been disconnected, air may be trapped inside the ABS modulator, which generally needs a dealer-level procedure or diagnostic tool to purge. Do not try to chase that out with the caliper bleeders alone.

Signs the Brakes Are Due for a Bleed

A soft or spongy lever, a lever that now travels closer to the grip than it used to, or a pedal that feels vague underfoot are the classic symptoms of air or tired fluid. Dark, cloudy, or discolored fluid in the reservoir is another clear signal. So is any recent work that opened the hydraulic system — new lines, caliper service, or master cylinder repairs.

Even with no symptoms at all, brake fluid absorbs moisture from the air over time, and that moisture lowers its boiling point. Under hard use, such as a long descent with a loaded bike, fluid that is past its prime can boil and produce fade right when you need the brakes most. Many riders simply refresh the fluid on a regular schedule as preventive maintenance.

Tools and Supplies to Gather

  • Fresh brake fluid of the type marked on the master cylinder reservoir cap, from a sealed container
  • A box-end wrench that fits the bleeder valve snugly
  • Clear tubing that fits tightly over the bleeder nipple
  • A small catch bottle for the old fluid
  • Rags or shop towels, plus a means of rinsing spills with water
  • A syringe or turkey baster for pulling old fluid out of the reservoir
  • The correct driver for the reservoir cap screws
  • Optional: a one-way check-valve bleeder or a vacuum bleeder, which makes a solo job much easier

Setting Up Safely

Get the bike secure and upright on a stand so it cannot tip while you are leaning on the lever. Turn the handlebars until the front reservoir sits level, because an angled reservoir will spill fluid the moment the cap comes off. Then drape rags over the painted bodywork, the plastics, and the instrument area.

Brake fluid attacks paint and plastic on contact, so treat every drip as urgent. Wipe spills immediately and rinse the area with water. Keep the old fluid in the catch bottle and dispose of it properly rather than pouring it down a drain.

The Bleeding Procedure, Step by Step

  1. Remove the reservoir cap and diaphragm and set them aside somewhere clean where they will not pick up grit.
  2. Use the syringe or baster to draw most of the old fluid out of the reservoir, but stop before the level drops far enough to let air into the master cylinder.
  3. Top the reservoir with fresh fluid from the sealed container.
  4. Push the clear tubing onto the bleeder valve and route the other end into the catch bottle, with the bottle positioned so you can see the fluid moving through the tube.
  5. Squeeze and hold the front lever firmly. Keep it held.
  6. Open the bleeder about a quarter turn and watch fluid and any air bubbles travel down the tube.
  7. Close the bleeder before you release the lever. Releasing with the bleeder open will pull air back into the caliper.
  8. Release the lever slowly, then repeat the squeeze, hold, crack, close, release cycle. Check the reservoir level every few cycles and top it off so it never runs low.
  9. Continue until the fluid coming through the tube is clean and free of bubbles, then move to the next caliper. If your bike has two front calipers, bleed each one in turn, working one at a time. A common general practice is to start with the caliper farthest from the master cylinder.
  10. Repeat the same process at the rear using the pedal, holding it down through each bleeder opening and closing the bleeder before you let the pedal return.

Finishing the Job

Once clean fluid is flowing at every point you are servicing, close the bleeder snugly. Snug is the goal — do not crank on it hard enough to damage the seat. Bring the reservoir up to the correct level marking, reinstall the diaphragm and cap, and wipe down any residue. Then inspect the bleeder and the banjo fittings at the caliper and master cylinder for weeping, and pump the lever a few times to confirm it builds pressure.

Test Before You Ride

The lever and pedal should feel firm and consistent, not spongy, and should not slowly sink while you hold steady pressure. Spin each wheel by hand to confirm the brakes are not dragging. Then find a safe, empty area and test the brakes at low speed before riding normally.

When to Stop and Call a Shop

If the lever will not firm up after several rounds of bleeding, if it only firms up when you pump it, if bubbles keep appearing no matter how long you work, or if you see fluid weeping from the master cylinder or a caliper, stop and get the bike looked at. The same applies if the reservoir ran dry, if air may have entered the ABS unit, or if you are unsure about the sequence for the combined brake hardware. Those situations are worth a professional's time on a motorcycle this heavy and this fast.

Related Shopping Categories

Shop Brake Fluid for a 2006 Honda ST1300 Motorcycle.

Shop Brake Lines for a 2006 Honda ST1300 Motorcycle.

Shop Brake Pads for a 2006 Honda ST1300 Motorcycle.

Shop Stands for a 2006 Honda ST1300 Motorcycle.

Shop Brake Tools for a 2006 Honda ST1300 Motorcycle.

Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.