Bleeding the Brakes on a 2018 Ducati Scrambler Cafe Racer
Shop parts for a 2018 Ducati Scrambler Cafe Racer Motorcycle.
The 2018 Ducati Scrambler Cafe Racer stops with hydraulic disc brakes at both ends, and it came from the factory with an anti-lock braking system. That means there are two separate hydraulic circuits to think about when you service the brakes: a front circuit fed by the master cylinder on the right handlebar, and a rear circuit fed by the pedal-mounted master cylinder. Both use brake fluid, both can collect air, and both benefit from a periodic flush. This guide walks you through refreshing the fluid and purging air from each circuit in your own garage, and it also tells you plainly when the job should go to a shop instead.
Why Brake Fluid Needs Replacing
Brake fluid is hygroscopic, which is a fancy way of saying it pulls moisture out of the air over time. That moisture does two harmful things. It lowers the fluid’s boiling point, so hard, repeated braking can boil the fluid and produce a spongy lever or pedal at exactly the wrong moment. It also encourages corrosion inside the calipers and master cylinders. On top of that, the fluid darkens and collects debris as seals wear.
You do not need a symptom to justify a flush, but symptoms are a good reminder. A lever that feels soft or pulls closer to the grip than it used to, a pedal with excessive travel, fluid that looks dark or cloudy in the reservoir window, or any recent work that opened the hydraulic system — new lines, caliper service, master cylinder repair — all point to a bleed. If the reservoir has ever run dry, air is almost certainly in the system and bleeding is mandatory before you ride.
Gather Your Tools and Supplies
- Fresh brake fluid of the type printed on your master cylinder reservoir cap, from a sealed container. Do not substitute a different type.
- 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 bleeder.
- A length of clear tubing that fits tightly over the bleeder nipple, plus a small 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 — usually a Phillips or a Torx on this bike, so check before you start.
- Optional but genuinely helpful: a one-way check-valve bleeder or a vacuum bleeder, either of which makes a solo job much less fiddly.
Set Up the Bike and Protect the Finish
Get the Scrambler Cafe Racer securely upright on a stand so it cannot tip while you are working. For the front circuit, turn the handlebars until the reservoir on the right bar sits level; a tilted reservoir will spill fluid the moment you open the cap. Lay rags over the tank, the instrument cluster, the headlight area, and any painted or plastic surface near the reservoir and caliper. Brake fluid attacks paint and many plastics on contact, so treat every drop as a problem. If a spill happens, wipe it up immediately and rinse the area with water.
Bleeding the Front Brake
- Remove the reservoir cap and the diaphragm beneath it, then 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.
- Refill the reservoir with fresh fluid from your sealed container, keeping it well above the minimum line.
- Slip the clear tubing over the front caliper bleeder and route the other end into the catch bottle. Position the bottle so the tubing runs upward from the bleeder before dropping to the bottle, which helps you see bubbles.
- Fit the box-end wrench on the bleeder. Squeeze the front lever and hold it firmly against the grip.
- With the lever held, open the bleeder about a quarter turn. Fluid and any trapped air will push out through the tubing. Watch the reservoir level as you do this.
- Close the bleeder before you release the lever. Releasing 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–hold–open–close–release cycle. Top off the reservoir every few cycles so it never runs low enough to pull air in.
- Continue until the fluid coming through the tubing is clean, fresh-looking, and free of bubbles, and the lever feels firm.
If your bike has two front calipers, bleed each one in turn, and start with the caliper farthest from the master cylinder in terms of hydraulic path. The general practice of beginning with the farthest caliper applies to any multi-caliper setup.
Bleeding the Rear Brake
The rear circuit works the same way with one key difference: you operate the pedal instead of a lever. Open the rear reservoir, remove most of the old fluid, and top it up with fresh fluid. Attach the tubing and catch bottle to the rear caliper bleeder, press and hold the pedal, crack the bleeder a quarter turn, then close it before releasing the pedal. Repeat until the fluid runs clean and bubble-free and the pedal feels solid. Keep an eye on the reservoir throughout — the rear reservoir is often smaller and empties faster than you expect.
Finishing and Checking Your Work
When both circuits are bled, tighten each bleeder snugly with the box-end wrench. Snug is the goal; overtightening can damage the bleeder seat and cause a leak. Fill each reservoir to the correct level marking, reinstall the diaphragm and cap, and wipe down every surface you touched. Look closely at the bleeder valves and at the banjo fittings at the master cylinder and caliper for any weeping or dampness. A dry fitting after a few minutes of sitting is what you want to see.
Testing Before You Ride
Squeeze the front lever and press the rear pedal several times. Both should feel firm and consistent, and neither should slowly sink while you hold steady pressure. Spin each wheel by hand to confirm the brakes are not dragging. Then, in a safe, empty area at low speed, apply each brake individually and confirm it engages smoothly and predictably before you ride normally.
When to Take It to a Shop
Some problems are not solvable with a bleeder bottle. If the lever or pedal will not firm up after several honest bleeding attempts, if it only firms up after repeated pumping, if bubbles keep appearing no matter how long you bleed, or if you find fluid leaking from a master cylinder or caliper, stop and have the bike inspected. Because this Scrambler Cafe Racer has ABS, there is one more consideration: a normal bleed at the caliper bleeders is fine for routine fluid refresh, but if the reservoir ran dry or the ABS unit or its lines were disconnected, air may have entered the ABS unit itself. That typically requires a dealer-level procedure or diagnostic tool, so send the bike to a shop rather than trying to force it out at the calipers.
Related Shopping Categories
Shop Brake Fluid for a 2018 Ducati Scrambler Cafe Racer Motorcycle.
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Shop Stands for a 2018 Ducati Scrambler Cafe Racer Motorcycle.
Shop Brake Tools for a 2018 Ducati Scrambler Cafe Racer 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.
