Bleeding the Brakes on a 2019 Honda Grom ABS
Shop parts for a 2019 Honda Grom ABS Motorcycle.The 2019 Honda Grom ABS uses hydraulic disc brakes at the front and rear, and this is the ABS-equipped version of the Grom. That matters because a normal caliper bleed is still the right way to refresh fluid and remove air from the lines and calipers, but air that has traveled into the ABS hardware is a different job. This guide walks through a careful bleed for the Grom ABS, including the checks that tell you when to stop and hand the bike to a shop.
When the Grom ABS Needs a Brake Bleed
A spongy front lever or a rear pedal that feels soft and vague is the classic sign that air is in the hydraulic system. So is a lever that pulls closer to the grip than it used to, or a pedal that sinks slowly under steady pressure. Dark, cloudy, or contaminated fluid in the reservoir is another reason to bleed. You should also bleed after any work that opened the hydraulic system, such as replacing a brake line, servicing a caliper, or repairing the master cylinder.
Brake fluid absorbs moisture over time, which lowers its boiling point and can lead to brake fade under hard use. That is why many riders refresh the fluid on a regular schedule even when the brakes still feel normal. On the 2019 Grom ABS, if the reservoir has run dry or the ABS unit or its lines have been disconnected, air may have entered the ABS hardware. A standard bleed at the calipers may not remove it, and the bike should go to a shop for the appropriate ABS procedure.
Tools and Supplies to Have Ready
- 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 used 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 if you pay attention. Keep the fluid container closed when you are not pouring, and never top off with fluid that has been sitting open or has been used before.
Preparing the Bike and Protecting Surfaces
Support the Grom ABS 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.
Set out your rags and catch bottle before you open the reservoir. Keep the reservoir cap and diaphragm clean and place them where they will not pick up grit. Work slowly enough that you are not rushing the lever or pedal, and keep the bleeder closed except when you are actually letting fluid out.
Bleeding the Front and Rear Hydraulic Brakes
The Grom ABS has separate front and rear hydraulic circuits, so treat each end as its own bleeding job. On a circuit with more than one caliper, the usual practice is to start with the caliper farthest from the master cylinder; on the Grom ABS, complete one end and then the other. Use the same sequence for the front lever and the rear pedal.
- Remove the reservoir cap and diaphragm. Use a syringe or turkey baster to remove most of the old fluid from the reservoir, but do not let it run dry. Leave enough fluid in the bottom so you do not push air into the system.
- Refill the reservoir with fresh fluid of the type marked on the cap. Keep the reservoir open while you bleed, but cover it loosely with a clean rag to keep debris out.
- Attach the clear tubing to the bleeder valve on the brake you are bleeding and route the other end into the catch bottle. Fit the box-end wrench onto the bleeder.
- For the front, squeeze the lever slowly and hold it firm. For the rear, press the pedal and hold it. Do not release the lever or pedal while the bleeder is open.
- Open the bleeder about a quarter turn and let fluid and air escape through the tube. Watch the tube for bubbles. Close the bleeder before you release the lever or pedal.
- Release the lever or pedal slowly. Check the reservoir and top it off with fresh fluid. Repeat the squeeze-hold-open-close-release sequence until fresh, clean, bubble-free fluid comes through the tube.
- Keep topping off the reservoir throughout the job so it never runs low enough to draw air in. When one end is done, close its bleeder and move to the other end.
If you see bubbles, keep going. If the lever or pedal starts to fade or feel inconsistent, stop and check the reservoir level and the bleeder seating before continuing.
Finishing Up and Verifying the Job
When the fluid runs clean and bubble-free, tighten the bleeder snugly without overtightening. Fill the reservoir to the correct level marking, then reinstall the diaphragm and cap. Clean any spilled fluid from the reservoir, caliper, and surrounding surfaces. Check for leaks at the bleeder and at the banjo fittings.
The lever and 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. Before riding normally, test the brakes at low speed in a safe area and make sure both ends slow the bike predictably.
Troubleshooting and When to Visit a Shop
If the lever or pedal will not firm up after several bleeding attempts, if it firms only after pumping, or if persistent bubbles keep appearing, stop and look for a source of air or a leak. Fluid leaking from the master cylinder or caliper is another reason to stop. Any situation where air may have entered the ABS unit, such as a reservoir that ran dry or ABS lines that were disconnected, should go to a shop with the proper ABS service procedure and tool.
The Grom ABS does not use a linked brake system, so you are not juggling a combined front-and-rear sequence, but the ABS hardware still makes certain air pockets a shop-level concern. If you are not confident in the bleed or the brakes feel questionable afterward, do not ride the bike until the system has been checked.
Related Shopping Categories
Shop Brake Fluid for a 2019 Honda Grom ABS Motorcycle.
Shop Brake Lines for a 2019 Honda Grom ABS Motorcycle.
Shop Brake Pads for a 2019 Honda Grom ABS Motorcycle.
Shop Stands for a 2019 Honda Grom ABS Motorcycle.
Shop Brake Tools for a 2019 Honda Grom ABS 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.
