How to Bleed and Replace Brake Fluid on a 2015 Honda Rancher 420 4X4 DCT IRS EPS (FA6)
Shop parts for a 2015 Honda Rancher 420 4X4 DCT IRS EPS (FA6) ATV.
This MotoSport guide shows a professional, step-by-step method to drain, replace, and properly bleed the brake system on a 2015 Honda Rancher 420 4X4 DCT IRS EPS (FA6). Follow these steps for safe, repeatable results. Read the safety notes and model-specific tips before starting.
What you need
- Honda-approved DOT brake fluid (use the grade recommended in your owner's manual — DOT 3 or DOT 4 compatible fluids; never mix mineral oil systems)
- Clear hose sized to bleeder nipple, clean container for old fluid
- Wrench set (bleeder nipple size typically 8mm or 10mm), line wrench recommended
- Brake fluid syringe or vacuum bleeder (recommended for clean, fast work)
- Turkey baster or fluid transfer pump to remove fluid from master cylinder
- Clean shop rags, gloves, eye protection
- Jack and stands or ramps to safely elevate and support the ATV (if wheel access required)
- Assistant (recommended for pedal or lever pumping method)
Model notes & tips specific to the 2015 Rancher 420 FA6
- The Rancher 420 FA6 uses hydraulic disc brakes on the front and a hydraulic rear disc or drum wheel cylinder depending on trim; confirm your configuration before starting.
- The DCT (Dual Clutch Transmission) is separate from the hydraulic brake system — there is no hydraulic clutch fluid to confuse with brake fluid on this model.
- EPS (Electric Power Steering) and IRS (Independent Rear Suspension) do not require brake system disassembly, but be careful routing hoses and working around wiring and tie-in points.
- Master cylinder reservoir is translucent plastic with level markings. Keep it capped except when adding fluid to avoid contamination and moisture absorption.
- This model is sensitive to water in brake fluid. Replace fluid fully if it's dark, contaminated, or more than 1-2 years old.
Safety first
- Work on a cool machine on a flat surface, in a well-ventilated area. Avoid open flames near brake fluid.
- Brake fluid damages paint & plastic. Protect painted surfaces and immediately clean spills with water followed by a mild detergent.
- Dispose of old fluid per local hazardous waste regulations.
Procedure overview
There are two commonly used methods: vacuum/pressure bleeding (fast, clean) and manual pump-bleed with an assistant. Choose one; vacuum or pressure is preferred for one-person, clean operation.
Step-by-step — full fluid replacement and bleed
- Park the ATV, engage parking brake, and remove key. Securely raise and support the machine if you need wheel access.
- Clean the master cylinder cap area. Remove the cap and diaphragm. Use a turkey baster or fluid transfer pump to remove as much old fluid from the reservoir as possible without introducing air. Wipe the inside of the cap and mating surfaces with a lint-free cloth.
- Top the reservoir with fresh brake fluid to the upper mark. Keep the reservoir capped between steps to minimize moisture pickup.
- If using a vacuum bleeder: attach the clear hose from the bleeder to the bleeder valve and the vacuum unit. If using pressure bleeder: pressurize the master cylinder reservoir per the tool manufacturer. If pumping manually: have an assistant sit on the machine to operate the brake lever/pedal.
- Identify bleed sequence. General rule: start with the wheel farthest from the master cylinder and work toward the closest. On most Rancher layouts this typically means: rear right (if separate), rear left, front right, front left. Confirm routing visually and start with the caliper/wheel cylinder farthest away.
- Loosen the bleeder nipple slightly, attach your clear hose, and open the valve about 1/4 turn. For vacuum bleed, actuate the tool until clear, bubble-free fluid flows and no air appears. For pressure bleed, pressurize and open each bleeder until clean fluid emerges. For manual bleed: with an assistant holding the lever/pedal, open the bleeder, allow fluid to flow until clean, then close the bleeder before the assistant releases the lever/pedal. Repeat pump/open/close cycles until only clear fluid and no bubbles appear.
- Keep the reservoir topped between wheels. Never let the master cylinder run dry or you will reintroduce air into the system.
- Repeat for each wheel in sequence. After the final wheel bleed, go back and re-check each bleeder quickly for leaks and residual air.
- Once bleeding is complete, top the reservoir to the proper level, reinstall the diaphragm and cap, and torque any hardware per Honda specs where applicable. Clean any spilled fluid thoroughly.
- Test lever and pedal firmness with the engine off first. Then conduct a cautious low-speed brake test in a safe area to confirm firm, consistent braking before resuming normal use.
Troubleshooting and checks
- Soft or spongy lever after bleeding: likely air remains. Re-bleed the system with emphasis on high points in the lines and the master cylinder.
- Still soft after multiple bleeds: inspect for leaking calipers, hoses, or a damaged master cylinder. Replace faulty components.
- Contaminated or dark fluid: replace completely by repeatedly drawing fluid from the reservoir and bleeding until new fluid appears clear at each wheel.
- If you need to bench-bleed a replaced master cylinder, do so before installation to avoid introducing air into the system.
Maintenance interval & recommendations
- Inspect fluid yearly and replace every 1-2 years if you ride in wet/muddy conditions or heavy use; otherwise replace at least every two years to prevent moisture-related boiling and corrosion.
- Keep a spare master cylinder diaphragm and quality bleeder caps in your tool kit. Use OEM or high-quality replacement parts for sealing surfaces.
Final notes specific to the FA6 owner
- Because the FA6 Rancher may see work around the EPS and wiring harnesses, protect connectors and avoid contaminating electrical components with brake fluid.
- If your Rancher has aftermarket accessories that alter braking loads (heavy racks, winches, passenger seats), inspect brake performance sooner and consider more frequent fluid changes.
- Record the service in your maintenance log at MotoSport so you track fluid age and future replacement intervals.
Perform the work with care; if you encounter persistent issues or hardware failure, consult a trained technician. Proper fluid and careful bleeding restore safe stopping performance on your Rancher 420 FA6.
Related Shopping Categories
Shop Brake Fluid for a 2015 Honda Rancher 420 4X4 DCT IRS EPS (FA6) ATV.
Shop Brake Bleeders for a 2015 Honda Rancher 420 4X4 DCT IRS EPS (FA6) ATV.
Shop Brake Pads for a 2015 Honda Rancher 420 4X4 DCT IRS EPS (FA6) ATV.
Shop Brake Lines for a 2015 Honda Rancher 420 4X4 DCT IRS EPS (FA6) ATV.
Shop Brake Tools for a 2015 Honda Rancher 420 4X4 DCT IRS EPS (FA6) ATV.
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.
