How to Bleed the Brakes on a 2023 Ducati Monster 937
Shop parts for a 2023 Ducati Monster 937 Motorcycle.
The 2023 Ducati Monster 937 uses hydraulic disc brakes at both wheels and is equipped with ABS. That means the front lever and rear pedal each push fluid through a closed hydraulic circuit to the calipers, and a normal bleed at the caliper bleeders is the correct way to refresh old fluid and remove air from the calipers and lines. The ABS unit adds one important limit: if the reservoir has run dry, or the ABS unit or its lines have been disconnected, air may be trapped where a simple caliper bleed cannot reach it. In that case, stop and take the bike to a shop with the appropriate diagnostic equipment.
When a Monster 937 Needs a Brake Bleed
A spongy or soft front lever, a rear pedal that feels vague, or a lever that pulls closer to the grip than it used to are all signs that air or old fluid is affecting the system. Dark or cloudy fluid in the reservoir is another clear indicator. Bleeding is also due after any work that opened the hydraulic system, such as new brake lines, caliper service, or master cylinder work. Even without symptoms, brake fluid absorbs moisture over time, which lowers its boiling point and can lead to brake fade under hard use, so many riders refresh it on a regular schedule. If the lever or pedal feels soft or sinks under steady pressure, bleed the brakes before riding normally.
Tools and Supplies for the Job
- 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
- A length of clear tubing that fits snugly over the bleeder
- A catch bottle for old fluid
- Rags or shop towels
- A syringe or turkey baster for removing old fluid from the reservoir
- A screwdriver or driver that fits the reservoir cap screws
A one-way check-valve bleeder or a vacuum bleeder can make the job easier for one person, but the basic lever-and-bleeder method works fine with a helper or with careful setup. Keep the catch bottle stable and route the clear tube so you can watch the fluid and any bubbles coming out.
Preparation and Paint Protection
Support the bike securely upright on a stand so it cannot tip while you are working. Turn the handlebars so the front reservoir sits level before you open it. Cover painted surfaces, plastics, and the instrument area with rags, because most brake fluids damage paint and plastic on contact. If a spill happens, wipe it up immediately and rinse the area with water. Keep the reservoir cap and diaphragm clean, and set them somewhere they will not pick up grit. Work methodically and keep the catch bottle below the bleeder so fluid drains away from the caliper.
Bleeding the Front Brake
Work at the front master cylinder reservoir first. If your bike has two front calipers, bleed each one in turn. As a general practice, start with the caliper farthest from the master cylinder in the hose routing, then move to the other; if the routing is symmetrical, pick one caliper and finish it before moving to the second.
- Remove the reservoir cap and diaphragm. Use a syringe or turkey baster to remove most of the old fluid from the reservoir without letting it run dry.
- Refill the reservoir with fresh fluid of the type marked on the cap, from a sealed container. Leave enough room for the diaphragm and cap to go back on without overflowing.
- Fit the box-end wrench onto the bleeder valve on the caliper you are working on. Push the clear tubing onto the bleeder snugly and route the other end into the catch bottle.
- Slowly squeeze the front lever and hold it firm. Open the bleeder about a quarter turn and let fluid and air escape through the tube. Close the bleeder before you release the lever. Never release the lever while the bleeder is open, or air can be drawn back in.
- Check the reservoir level and top it off. Repeat the squeeze, hold, open, close, and release sequence until the fluid coming through the tube is fresh, clean, and free of bubbles. Keep topping off the reservoir throughout so it never runs low enough to draw air into the system.
- If your bike has two front calipers, repeat the same process on the other caliper, topping off the reservoir between calipers.
Bleeding the Rear Brake
The rear brake is a separate hydraulic circuit on this bike, so it needs its own bleed. Locate the rear reservoir cap; it may be under a cover or body panel. Protect the surrounding bodywork before opening it, and use the same fluid type marked on the cap.
- Open the rear reservoir and remove most of the old fluid with a syringe or turkey baster. Refill with fresh fluid from a sealed container.
- Fit the box-end wrench and clear tubing to the rear caliper bleeder, routing the tube into the catch bottle.
- Press and hold the rear pedal. Open the bleeder about a quarter turn, let fluid and air out, then close the bleeder before releasing the pedal.
- Top off the rear reservoir and repeat until the fluid in the tube is clean and bubble-free. Rear reservoirs can be small, so check the level often and never let it run dry.
- Finish by checking pedal firmness. If it still feels soft, repeat the sequence until it firms up consistently.
Finishing, Testing, and Troubleshooting
When the fluid runs clean at both ends, tighten each bleeder snugly without overtightening. Fill the reservoir to the correct level marking, reinstall the diaphragm and cap, and clean any spilled fluid from the bike. Check for leaks at the bleeder and at the banjo fittings before you ride. The front lever and rear pedal should feel firm and consistent, not spongy, and they should not slowly sink under steady pressure. Spin each wheel to confirm the brakes are not dragging. Test the brakes at low speed in a safe area before riding normally.
If the lever or pedal will not firm up after several bleeding attempts, if it firms only after pumping, if bubbles keep appearing, or if fluid is leaking from the master cylinder or caliper, stop and have the bike inspected. Any situation where air may have entered the ABS unit is also a shop-level job. A correct bleed leaves both brakes firm, clean, and ready for the road.
Related Shopping Categories
Shop Brake Fluid for a 2023 Ducati Monster 937 Motorcycle.
Shop Brake Lines for a 2023 Ducati Monster 937 Motorcycle.
Shop Brake Pads for a 2023 Ducati Monster 937 Motorcycle.
Shop Stands for a 2023 Ducati Monster 937 Motorcycle.
Shop Brake Tools for a 2023 Ducati Monster 937 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.
