Bleeding the Brakes on a 2024 Ducati Monster 937 Plus
Shop parts for a 2024 Ducati Monster 937 Plus Motorcycle.
Few maintenance jobs reward a home mechanic as directly as a proper brake bleed. On the 2024 Ducati Monster 937 Plus, the payoff is a lever and pedal that come back firm, consistent, and free of the vague, spongy feel that creeps in as fluid ages. The job is well within reach of a rider who is comfortable with hand tools, provided you work methodically and never let the system swallow air.
What You Are Working With on This Monster
The Monster 937 Plus uses hydraulic disc brakes at both ends, with a master cylinder and reservoir at the handlebar feeding the front calipers and a separate master cylinder and reservoir at the right footpeg feeding the rear. The bike is equipped with an ABS unit plumbed into the hydraulic circuits, which matters for how you approach the job. A routine fluid refresh done through the caliper bleeders is a normal garage task on this machine. What is not a garage task is purging air that has migrated into the ABS module itself — that scenario calls for a dealer-level procedure and diagnostic equipment, and it is covered further down.
The front end carries two discs and two calipers, so you will service each caliper separately rather than treating the front as a single circuit. The rear is a single caliper. There is no linked braking on this model, so the front lever and rear pedal operate independently and each circuit is bled on its own.
Recognizing When a Bleed Is Due
The classic signal is feel. A lever that pulls noticeably closer to the grip than it used to, or a pedal with a soft, springy travel before it bites, usually means air or moisture has found its way into the fluid. Dark, cloudy, or discolored fluid visible through the reservoir sight glass is another clear indicator, as is any gritty sediment sitting at the bottom of the reservoir.
Bleeding is also mandatory after any work that opened the hydraulic system: new brake lines, caliper removal or rebuild, master cylinder service, or a reservoir that ran dry. Beyond symptoms, brake fluid is hygroscopic, meaning it absorbs moisture from the air over time. That moisture lowers the fluid's boiling point, and under hard, repeated braking it can vaporize and produce a long, frightening lever. Many riders simply refresh the fluid on a regular interval as preventive maintenance rather than waiting for a problem to announce itself.
Tools and Supplies to Assemble
- Fresh brake fluid of the type printed on the master cylinder reservoir cap, from a sealed container — once a container is opened, it starts absorbing moisture
- A box-end wrench that fits the bleeder valve snugly
- Clear tubing sized to fit tightly over the bleeder nipple
- A small catch bottle for the old fluid
- Rags or shop towels, plus a syringe or turkey baster for drawing 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, both of which simplify the job for a solo mechanic
Setting Up Before You Open Anything
Get the bike secure and upright on a stand so the reservoirs sit level. For the front, turn the handlebar until the reservoir on the master cylinder is horizontal; a tilted reservoir will spill fluid the moment the cap comes off. Lay rags over the instrument cluster, the top of the bodywork, and anything painted or plastic near the work area. Brake fluid attacks paint and clear plastic on contact, so treat every drop as a problem. If a spill does happen, wipe it up immediately and flush the area with water.
Bleeding the Front Circuit
- Remove the reservoir cap and diaphragm, then use the syringe or baster to draw most of the old fluid out. Leave a small amount at the bottom so you do not push air into the master cylinder.
- Refill with fresh fluid from the sealed container, keeping the level well above the minimum mark.
- Press the clear tubing onto the front caliper bleeder and route the other end into the catch bottle, with the bottle positioned so the tubing runs upward before it drops — this traps air at the high point.
- Squeeze the front lever smoothly and hold it against the grip.
- 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 fully before you release the lever. Releasing with the bleeder open draws air straight back into the caliper.
- Repeat the squeeze–hold–open–close–release cycle, topping off the reservoir between rounds, until the fluid arriving in the tubing is clean and free of bubbles.
- Move to the second front caliper and repeat the entire sequence. Working the caliper farthest from the master cylinder first is the usual practice, so start with the one on the side opposite the lever.
Bleeding the Rear Circuit
- Confirm the rear reservoir at the master cylinder is clean and topped up, and fit the tubing to the rear caliper bleeder.
- Press and hold the brake pedal down firmly.
- Open the bleeder a quarter turn, let fluid and air escape, then close it before releasing the pedal.
- Repeat, checking the reservoir level frequently, until the fluid runs clear and bubble-free.
Finishing the Job
Snug the bleeder valves down firmly with the box-end wrench — tight enough to seal, but never so tight that you risk damaging the caliper threads. Fill each reservoir to the level marking, reinstall the diaphragm and cap, and wipe down every surface you touched. Then inspect the bleeder fittings and the banjo bolts at the calipers and master cylinders for any weeping or dampness.
Verifying the Result Before You Ride
With the bike still stationary, pull the front lever and press the rear pedal several times. Both should feel firm and consistent, and neither should slowly sink toward the grip or the floor under steady pressure. Spin each wheel by hand to confirm the brakes are not dragging. Then, in a safe, empty area, test the brakes at low speed before riding normally.
When to Hand It Off to a Shop
If the lever refuses to 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 work, stop and reassess. Persistent air, fluid weeping from a master cylinder or caliper, or any suspicion that the reservoir ran dry and pulled air into the ABS unit all point to a job for a shop with the right diagnostic equipment. On an ABS-equipped Monster like this one, that is not a defeat — it is the correct call.
Related Shopping Categories
Shop Brake Fluid for a 2024 Ducati Monster 937 Plus Motorcycle.
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Shop Brake Tools for a 2024 Ducati Monster 937 Plus 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.
