Bleeding the Brakes on a 2016 Ducati Hypermotard 939 SP
Shop parts for a 2016 Ducati Hypermotard 939 SP Motorcycle.What You're Working With on the 939 SP
The 2016 Hypermotard 939 SP uses hydraulic disc brakes at both ends. The front circuit is fed by a master cylinder on the right handlebar, and the rear is operated by a foot pedal on the right side of the bike. The two circuits are completely independent, so each one gets bled on its own and each has its own reservoir that must be watched while you work. This model also came with ABS, which changes one thing about the job: a normal fluid flush through the caliper bleeders is still the correct approach for routine maintenance, but if air has been allowed into the ABS unit itself — the reservoir ran dry, the module was removed, or a line was disconnected — the fix is not a home garage procedure. That air has to be purged by cycling the pump with a dealer-level tool, so if you suspect it got that far, stop and book the bike in.
One more detail worth knowing before you start: if your bike carries two front calipers, treat them as two separate bleed points and work them one at a time. Rushing back and forth between them usually just pushes old fluid around.
Why Fluid Goes Off and When to Bleed
Brake fluid is hygroscopic, meaning it pulls moisture out of the air over time, even through sealed rubber components. As water content climbs, the fluid's boiling point drops. That is fine on a gentle commute, but under repeated hard braking the fluid can boil and create vapor in the lines, and vapor compresses where liquid does not. The result is a lever that goes soft or long exactly when you need it most. This is why plenty of riders refresh the fluid on a schedule rather than waiting for a symptom.
Bleed the system when the lever or pedal feels spongy, when the lever now travels closer to the grip than it used to, when the fluid in the reservoir looks dark or cloudy instead of clear, or after any job that opened the hydraulic system — new lines, caliper service, or master cylinder work. A lever that firms up only after two or three quick pumps is another classic sign that air is in there.
Tools and Supplies to Gather
- Fresh brake fluid of the type printed on the master cylinder reservoir cap, from a sealed container
- A box-end wrench that fits the bleeder valve snugly
- A length of clear tubing that fits tightly over the bleeder nipple
- A small catch bottle to hang or set below the caliper
- Rags or shop towels, plus a syringe or turkey baster for emptying the reservoir
- The correct driver or screwdriver for the reservoir cap screws
- Optional: a one-way check-valve bleeder or a vacuum bleeder, which makes a one-person job far less fiddly
Setting Up the Bike and Protecting the Finish
Get the bike securely 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 the moment the cap comes off. Before you open anything, drape rags over the bodywork, the painted surfaces, and the instrument area. Brake fluid attacks paint and many plastics on contact, and a single drip left sitting will leave a mark. If a spill does happen, wipe it up immediately and rinse the area with water rather than wiping it dry.
It also helps to pump the lever a few times before you begin and hold pressure on it while you inspect the caliper, line, and banjo fittings. If anything weeps now, you want to know before you add fresh fluid.
The Bleeding Procedure, Step by Step
- Start with the front circuit. With the bike on the stand and the bars set so the reservoir is level, remove the cap and the diaphragm and set them on a clean rag.
- Use the syringe or baster to draw most of the old fluid out of the reservoir. Leave a little in the bottom so you do not push air into the master cylinder.
- Top the reservoir up with fresh fluid from the sealed container.
- Push the clear tubing onto the bleeder valve and route the other end into the catch bottle. A bottle with a splash of fluid already in it keeps air from being drawn back up the tube.
- Squeeze the lever firmly and hold it in.
- Open the bleeder about a quarter turn and watch the fluid and air travel down the tube.
- Close the bleeder before you release the lever. Releasing with the bleeder open draws air straight back into the caliper.
- Release the lever slowly, then repeat the squeeze, hold, open, close, release cycle.
- Check the reservoir level every few cycles and top it off. Never let it drop low enough to pull air in — that turns a twenty-minute job into an afternoon.
- Keep going until the fluid coming through the tube is clean, fresh, and completely free of bubbles.
- If your bike has two front calipers, repeat the whole sequence on the second caliper. As a general practice, start with the caliper farthest from the master cylinder and finish with the closer one.
- Move to the rear circuit and run the same sequence using the pedal, again topping the rear reservoir as you go.
Finishing the Job Correctly
When the fluid runs clear at every bleeder, close each valve snugly. Snug is the goal — do not lean on the wrench and crush the sealing surfaces. Fill the reservoir to the level marking on the body, reinstall the diaphragm and cap, and wipe down every surface you touched. Then look closely at each bleeder and each banjo fitting for weeping, and leave the bike sitting for a few minutes with pressure held on the lever to confirm nothing seeps.
Testing Before You Ride
The lever and pedal should feel firm and consistent, and neither should slowly sink while you hold steady pressure. Spin each wheel by hand and listen and feel for drag — a caliper that grabs or a wheel that will not spin freely needs attention before you go anywhere. Finally, roll out to an empty lot or quiet street and test the brakes at low speed, building up gradually. If anything feels vague, long, or inconsistent, go back and bleed again rather than telling yourself it will settle in.
When to Hand It to a Shop
Some problems will not resolve with more pumping. If the lever refuses to firm up after several honest attempts, if it only firms up when you pump it, if bubbles keep appearing no matter how long you bleed, or if fluid is weeping from the master cylinder or a caliper, stop and let a professional look at it. The same applies to any situation where air may have entered the ABS unit. On a safety-critical system like this one, knowing when to stop is part of the skill.
Related Shopping Categories
Shop Brake Fluid for a 2016 Ducati Hypermotard 939 SP Motorcycle.
Shop Brake Lines for a 2016 Ducati Hypermotard 939 SP Motorcycle.
Shop Brake Pads for a 2016 Ducati Hypermotard 939 SP Motorcycle.
Shop Stands for a 2016 Ducati Hypermotard 939 SP Motorcycle.
Shop Brake Tools for a 2016 Ducati Hypermotard 939 SP 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.
