How to Bleed & Replace Brake Fluid on a 2019 Honda TRX500 Rubicon 4X4 POWER STEERING (FM6)

Shop parts for a 2019 Honda TRX500 Rubicon 4X4 POWER STEERING (FM6) ATV.

This MotoSport-proprietary guide covers safe, repeatable steps to flush and bleed the hydraulic brake system on a 2019 Honda TRX500 Rubicon 4X4 Power Steering (FM6). Follow these instructions exactly, use the right tools and fluid, and observe safety practices. If you’re not confident, seek a qualified technician.

What you need

  • DOT 4 brake fluid (Honda recommends DOT 4; do not mix with power steering fluid)
  • Clear vinyl tubing to fit bleed nipples
  • Catch bottle with shallow level of brake fluid and a small amount of mineral oil in the bottom to prevent suction (or an inline one-way bleed bottle)
  • Brake bleeder kit or vacuum pump (optional but speeds the job)
  • 10 mm wrench (bleed nipple) and appropriate wrenches for caliper bolts
  • Clean rags, brake-clean spray, nitrile gloves, safety glasses
  • Jack and stands or ramps to safely support the ATV if needed
  • Small funnel and clean container for fresh fluid transfer

Model notes & precautions for the TRX500 Rubicon 4X4 POWER STEERING

  • The TRX500R_PS uses hydraulic front and rear disc brakes and a separate hydraulic power steering system. Brake fluid must never be used for or mixed with power steering fluid.
  • Reservoirs: the brake master cylinder reservoir is on the handlebar area. Power steering reservoir is separate and located near the engine steering assembly. Confirm you’re topping/bleeding the brake reservoir only.
  • DOT grade: use DOT 4. Do not use DOT 5 (silicone) or any fluid labeled incompatible with DOT 4 systems.
  • Routine: replace brake fluid every 2 years or sooner if contaminated, spongy brake lever/pedal feel, or after repairs.
  • ABS/complex systems: this FM6 Rubicon does not have motorcycle-style ABS on the ATV brakes that would require scanner or ABS cycling procedures, but always verify your machine does not have additional modules before beginning.

Preparation

  • Park the ATV on level ground, engage parking brake, shift to Park, and remove the key.
  • Clean the master cylinder reservoir and surrounding area to prevent dirt entry when opening.
  • Remove reservoir cap and diaphragm; cover the opening with a clean rag to limit contamination.
  • Inspect lines, hoses, calipers and fittings for leaks or damage. Replace any cracked lines or damaged components before bleeding.
  • Identify caliper bleed nipples. Mark positions to track sequence.

Bleeding strategy

Always bleed from the caliper farthest from the master cylinder toward the closest caliper. Farthest-first removes trapped air fastest. If unsure which is farthest, use the longest hydraulic line route as the first target. Use either a vacuum bleeder, pressure bleeder, or two-person pump-and-hold method.

Typical sequence (verify on machine):

  • 1st: Rear caliper (usually farthest)
  • 2nd: Right front caliper
  • 3rd: Left front caliper

Step-by-step bleeding procedure

  1. Top off the master cylinder reservoir with fresh DOT 4 brake fluid. Keep the cap loosely in place between steps to reduce contamination.
  2. Start with the farthest caliper. Place clear tubing on the bleed nipple and route to the catch bottle. Ensure the tubing end is submerged in a small amount of fresh fluid in the catch bottle to prevent air reentry.
  3. Crack the bleed nipple about a quarter turn using the 10 mm wrench. Do not fully remove the nipple.
  4. If using a vacuum pump: apply steady vacuum at the caliper bleed nipple and open the nipple until fluid flows clear of bubbles, then close nipple and release vacuum. Repeat until only clean fluid flows.
  5. If using a one-person pedal method: have an assistant slowly pull the brake lever/pedal and hold it. Open the nipple so fluid and air escape, then close the nipple. Instruct assistant to release lever slowly. Repeat pump, hold, open, close cycles until bubble-free fluid appears.
  6. If using gravity bleeding: open the nipple and let fluid flow slowly, topping reservoir as needed. This is slower and may not remove all air; use only if other methods unavailable.
  7. After the caliper runs clear, tighten the bleed nipple securely (do not over-torque). Wipe any spilled fluid immediately from painted and plastic surfaces.
  8. Repeat steps for next caliper in sequence, always keeping an eye on reservoir level and topping with fresh DOT 4 fluid to prevent drawing air into the system.
  9. When all calipers are clear, perform a final check: press the brake lever/pedal firmly to confirm firm, consistent feel. Recheck all bleed nipples and reservoir cap for tightness.
  10. Start the engine briefly and cycle the steering while checking for leaks and confirming brake performance at low speed in a safe area.

If brakes remain spongy

  • Repeat the bleeding cycle, paying special attention to the caliper closest to the master cylinder — sometimes residual air hides there.
  • Inspect for collapsed flexible hoses or internal caliper issues; replace suspect components.
  • Use a bench-bleed procedure on the master cylinder if the master itself is suspected of containing air.

Finish, cleanup & disposal

  • Wipe all areas where brake fluid contacted paint or plastics with clean water and a rag; brake fluid can damage finishes.
  • Refill reservoir to correct level and securely install cap and diaphragm.
  • Properly dispose of used brake fluid per local hazardous-waste rules. Do not pour down drains.
  • Log the service date and note next recommended fluid change (about 24 months).

Special notes for the TRX500 owner

  • Do not confuse the brake reservoir with the power steering reservoir — cross-contamination will damage the steering system.
  • If you do any front suspension work that opens brake lines, bleed immediately after reassembly.
  • Keep DOT 4 fluid sealed and away from sunlight; contaminated or aged fluid absorbs moisture which reduces braking performance.
  • MotoSport recommends using OEM-quality replacement lines, seals and bleeder screws when parts are needed to ensure fit and corrosion resistance in off-road environments.

Following these steps will restore a firm brake feel and maintain safe stopping performance on your 2019 Honda TRX500 Rubicon 4X4 POWER STEERING. If you need replacement parts or bleeder tools, Shop parts for your ride now!

Related Shopping Categories

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Shop Brake Pads for a 2019 Honda TRX500 Rubicon 4X4 POWER STEERING (FM6) ATV.

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Shop Brake Tools for a 2019 Honda TRX500 Rubicon 4X4 POWER STEERING (FM6) 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.