Bleeding the Brakes on a 1995 Honda ST1100
Shop parts for a 1995 Honda ST1100 Motorcycle.
What the ST1100's Brake System Looks Like
The 1995 ST1100 is a sport-tourer that carries a lot of mass and speed, and Honda gave it hydraulic disc brakes at both ends to manage that. Up front you have a pair of calipers gripping twin discs, and out back a single caliper on a rear disc, each end fed by its own master cylinder and reservoir. The front reservoir lives on the handlebar; the rear master cylinder is mounted low on the bike with its own remote reservoir, so you will be working in two different places during this job. The standard 1995 ST1100 does not use a linked or combined braking system, which keeps things straightforward: the front lever works the front brakes, the rear pedal works the rear. If your particular example is an ABS-equipped variant, the same caliper-level bleeding process still refreshes fluid, but any air that has traveled into the ABS unit itself is a different problem and is covered near the end of this article.
Why and When to Bleed
Brake fluid is hygroscopic, meaning it pulls moisture out of the air over time. That moisture does two bad things: it lowers the fluid's boiling point, so hard repeated braking can boil the fluid and give you a soft, fading lever, and it corrodes the internals of the master cylinder and calipers from the inside. On a bike that is now decades old, this matters more than on a new one.
Bleed the system when the lever or pedal feels spongy, when the lever travels closer to the grip than it used to, when the fluid in either reservoir looks dark or cloudy, or after any work that opened the hydraulics — new lines, caliper service, master cylinder work, or a reservoir that ran dry. Many riders also simply refresh the fluid on a regular interval as preventive maintenance, since a system can degrade noticeably before the lever ever feels wrong.
Tools and Supplies to Collect First
- Fresh brake fluid of the type printed on the master cylinder reservoir cap, from a sealed container — opened fluid absorbs moisture, so do not use a bottle that has been sitting around
- A box-end wrench that fits the bleeder valve snugly; a box-end grips better than an open-end and is less likely to round the hex
- A length of clear tubing that fits tightly over the bleeder nipple, plus a catch bottle to hang it in
- Rags or shop towels, and a syringe or turkey baster for pulling old fluid out of the reservoir
- The correct driver for the reservoir cap screws
- Optional but helpful: a one-way check-valve bleeder or a vacuum bleeder, which makes a one-person job much easier
Setting Up Safely
Get the bike on a stand so it is stable and upright, not leaning on the sidestand. For the front, turn the handlebars until the front reservoir sits level — a reservoir that is tilted will spill as soon as you open it. Drape rags over the tank, the fairing panels, the instrument cluster, and anything else below the reservoir, because brake fluid attacks paint and clear plastic on contact. If a drop does land on a painted or plastic surface, wipe it up immediately and rinse the area with water rather than waiting until you finish.
The Bleeding Procedure
- Clean the top of the reservoir before opening it so dirt does not fall in, then remove the cap and the rubber diaphragm beneath it.
- Use the syringe or baster to draw most of the old fluid out of the reservoir. Leave enough at the bottom that you are not pulling air into the master cylinder port.
- Top the reservoir up with fresh fluid from your sealed container.
- Push the clear tubing onto the bleeder valve and route the other end into the catch bottle, with the bottle positioned so the tube's end stays submerged.
- Squeeze the front lever and hold it firmly against the grip. Do not release it yet.
- With the lever held, open the bleeder about a quarter turn with the box-end wrench. You will see fluid and any trapped air push out through the tube.
- Close the bleeder before you let the lever go. Releasing the lever with the bleeder open draws air back into the caliper, which is the single most common mistake in this job.
- Release the lever slowly, then repeat the squeeze-open-close-release cycle. Check the reservoir level every few cycles and top it off — if it runs dry you will pull air into the master cylinder and have to start over.
- If your bike has two front calipers, bleed one caliper completely until the fluid runs clean and bubble-free, then move to the other. As a general practice, start with the caliper farthest from the master cylinder and work toward the closest.
- Once the front is done, close the bleeder snugly — firm, not cranked down hard, since overtightening can damage the seat — and move to the rear. The rear uses the same cycle with the pedal instead of the lever: press and hold the pedal, crack the bleeder, close it, then release.
- Continue each end until the fluid coming through the tube is visibly clean and free of bubbles, and the lever and pedal feel firm.
Finishing Up
Fill each reservoir to the level marking on the body, not to the brim. Reinstall the diaphragm so it sits flat and unfolded, then the cap. Wipe down the calipers, bleeders, and reservoir area, and rinse away any fluid that reached paint or plastic. Look closely at the bleeder valves and at the banjo fittings at the master cylinder and caliper for weeping or dampness, and check again after the bike has sat for a while.
Testing Before You Ride
With the bike still supported, spin each wheel by hand and confirm the brakes are not dragging. Then squeeze the lever and hold steady pressure for a slow count — it should feel firm and consistent and should not creep toward the grip. Do the same with the rear pedal. Take the bike to an empty lot or quiet street and test the brakes at low speed first, gradually building up, before riding normally.
When to Stop and See a Shop
If the lever will not firm up after several rounds of bleeding, if it only firms up when you pump it, or if bubbles keep appearing no matter how long you bleed, something else is wrong — a failing master cylinder seal, a pinhole in a line, or a fitting drawing air. Fluid weeping from the master cylinder or caliper is another stop sign. On an ABS-equipped ST1100, if the reservoir ever ran dry or the ABS unit or its lines were disconnected, air may be trapped where a hand bleed cannot reach it; that requires dealer-level equipment, so have the bike transported rather than ridden.
Related Shopping Categories
Shop Brake Fluid for a 1995 Honda ST1100 Motorcycle.
Shop Brake Lines for a 1995 Honda ST1100 Motorcycle.
Shop Brake Pads for a 1995 Honda ST1100 Motorcycle.
Shop Stands for a 1995 Honda ST1100 Motorcycle.
Shop Brake Tools for a 1995 Honda ST1100 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.
