How To Bleed 2017 Honda Grom Motorcycle Brakes

Bleeding the Brakes on Your 2017 Honda Grom

The 2017 Honda Grom uses a hydraulic disc brake at each end — a single front caliper fed by the lever-mounted master cylinder, and a single rear caliper fed by a pedal-driven master cylinder. There is no ABS unit and no linked brake system on this model year, which is good news for the home mechanic: both circuits are simple, self-contained, and can be bled with basic hand tools. This guide walks you through refreshing the fluid and purging air from both the front and rear systems on your Grom.

When a Bleed Is Due

The most obvious signal is feel. A lever or pedal that has gone spongy, or a front lever that now travels noticeably closer to the grip than it used to, usually means air has found its way into the circuit. Dark, cloudy, or discolored fluid in either reservoir is another clear indicator that a flush is overdue. You should also bleed after any job that opened the hydraulic system — replacing a line, servicing a caliper, or working on a master cylinder.

Even with no symptoms at all, brake fluid absorbs moisture from the air over time. That moisture lowers the fluid's boiling point, and under hard or repeated braking it can turn to vapor in the caliper, giving you a soft lever and reduced stopping power right when you need it most. Many riders simply refresh the fluid on a regular interval as preventive maintenance, and on a small bike like the Grom that is a cheap habit to keep.

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 on each caliper
• Clear tubing sized to fit snugly over the bleeder nipple
• A small catch bottle for the old fluid
• Rags or shop towels, plus water for rinsing spills
• A syringe or turkey baster for pulling old fluid out of the reservoir
• The correct driver for the reservoir cap screws

A one-way check-valve bleeder or a vacuum bleeder is not required, but either makes the job much easier to handle solo, since you are not relying on a helper to work the lever in time with your wrench.

Setting Up Safely

Get the Grom supported 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 lever perch sits level — an angled reservoir will spill. Brake fluid attacks paint and many plastics on contact, so drape rags over the tank area, the plastics, and the instrument cluster before you open anything. If a drop does land on a painted surface, wipe it up immediately and rinse the area with water rather than waiting until the end of the job.

Bleeding the Front Brake

1. Remove the reservoir cap and diaphragm. Use the syringe or baster to draw most of the old fluid out of the reservoir, but stop before the port at the bottom is exposed — never let the reservoir run dry, or you will pull air straight into the line.
2. Top the reservoir up with fresh fluid from your sealed container.
3. Slip the clear tubing over the front caliper bleeder and route the other end into the catch bottle, with the bottle positioned so the tubing runs upward away from the bleeder.
4. Squeeze the front lever and hold it firmly against the grip.
5. Open the bleeder about a quarter turn with the box-end wrench. Fluid and any trapped air will push out through the tubing.
6. Close the bleeder before you release the lever. Releasing with the bleeder open draws air back in through the nipple.
7. Release the lever slowly and repeat the squeeze-hold-open-close-release cycle. Check the reservoir level every few cycles and top it off as needed.
8. Keep going until the fluid coming through the tubing is clean and free of bubbles, then finish with the lever held and the bleeder closed.

The Grom has a single front caliper, so there is only one bleeder to work at the front. On any bike with two front calipers, the general practice is to bleed one caliper at a time, starting with the one farthest from the master cylinder in terms of hydraulic path.

Bleeding the Rear Brake

The rear circuit follows the same logic with the foot pedal in place of the lever. Confirm the rear reservoir — mounted near the pedal on the Grom — is level and accessible, protect the surrounding bodywork, and draw out the old fluid. Fit the tubing to the rear caliper bleeder, then press and hold the pedal, crack the bleeder a quarter turn, close it, and release. Repeat until the fluid runs clean and bubble-free, topping the reservoir as you go. Because the rear circuit is short, it usually purges quickly, but do not rush the final cycles.

Finishing and Checking Your Work

Snug the bleeder valves down firmly with the box-end wrench — tight enough to seal, but not 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. Look closely at the bleeder nipples and at the banjo fittings at both master cylinders and calipers for any weeping or dampness.

Before you ride, the lever and pedal should feel firm and consistent, and should hold pressure without slowly sinking when you squeeze or press and hold. Spin each wheel by hand to confirm the brakes are not dragging. Then, in a safe open area, test the brakes at low speed before riding normally.

Troubleshooting and When to Stop

If the lever refuses to firm up after several rounds of bleeding, or only firms up temporarily after pumping, air is still getting in somewhere — often past a worn master cylinder seal or a loose fitting. Persistent bubbles, fluid weeping from a master cylinder or caliper, or a pedal that behaves inconsistently all point to a problem a bleed will not fix. In those cases, stop and have the system inspected by a shop rather than continuing to chase the symptom on the road.

Related Shopping Categories

Shop Brake Fluid for a 2017 Honda Grom Motorcycle.

Shop Brake Lines for a 2017 Honda Grom Motorcycle.

Shop Brake Pads for a 2017 Honda Grom Motorcycle.

Shop Stands for a 2017 Honda Grom Motorcycle.

Shop Brake Tools for a 2017 Honda Grom 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.