How to Bleed & Replace Brake Fluid on a 2009 Yamaha Grizzly 350 4X4 IRS

Shop parts for a 2009 Yamaha Grizzly 350 4X4 IRS ATV.

This MotoSport-exclusive service guide covers step-by-step bleeding and replacing brake fluid on the 2009 Yamaha Grizzly 350 4X4 IRS. It's written for owners who want a reliable, safe brake fluid service using common tools and proven procedures specific to this MMY ATV.

Notes specific to the 2009 Yamaha Grizzly 350 4X4 IRS

  • The 2009 Grizzly 350 uses separate front and rear brake systems (separate master cylinders). Bleed and flush each system independently.
  • The ATV has independent rear suspension – reach the rear calipers by lifting the rear wheels and supporting the chassis on stands for safe access.
  • No factory ABS on this model; bleeding follows standard hydraulic procedures without ABS-specific steps.
  • Brake line routing and banjo fittings on the Grizzly are compact; inspect for chafing or corrosion while servicing. Replace copper crush washers on banjo bolts if disturbed.

Tools & materials

  • Manufacturer-recommended brake fluid (use the DOT spec listed in your owner's manual; protect against contamination)
  • Clear plastic tubing that fits the bleed nipple
  • Clean catch container partially filled with old fluid
  • Wrenches to fit bleed nipples and banjo bolts (usually 8-12 mm range depending on fasteners)
  • Turkey baster or syringe for removing fluid from reservoirs
  • Brake bleeder kit or a handheld vacuum pump (optional but speeds process)
  • Rags, gloves, eye protection; brake cleaner for cleanup
  • Floor stands or ramps to lift and safely support ATV

Preparation

  • Park on level ground, engage parking brake, remove key.
  • Clean around master cylinder reservoirs and bleed nipples to prevent dirt contamination.
  • Raise and support wheels where needed to access calipers. Do not rely on the jack alone.
  • Check owner's manual for the exact DOT fluid spec. Do not mix different DOT fluids unless compatible per manual.

Overall process overview

1) Remove old fluid from the reservoir. 2) Refill with fresh fluid. 3) Bleed each caliper until fresh, bubble-free fluid flows. 4) Top off reservoir and test pedal feel.

Detailed step-by-step: front and rear systems

Perform the entire sequence for the rear brake system first, then the front system, or vice versa — the important point is to treat each master cylinder independently and avoid cross-contamination.

1. Remove old fluid from reservoir

  • Open reservoir cap and diaphragm. Use a turkey baster or syringe to remove most of the old fluid. Wipe reservoir clean with a lint-free rag soaked in fresh fluid if needed.
  • Refill the reservoir to the specified fill level with new brake fluid. Keep the cap off but diaphragm in place so the system can breathe while you bleed.

2. Locate bleed nipples and attach tubing

  • Locate each caliper bleed nipple. Place clear tubing over the nipple and route the other end into a catch bottle partially filled with old fluid to prevent air from being sucked back in.
  • Ensure tubing seals snugly on the nipple.

3. Bleeding sequence

  • Standard sequence: start with the caliper farthest from the master cylinder and work toward the closest. For the Grizzly 350 this commonly means: rear passenger (farthest), rear driver, front passenger, front driver. Confirm which side your master is feeding first visually before starting and adjust sequence accordingly.
  • Have an assistant slowly depress the brake lever/pedal and hold it. Open the bleed nipple about 1/8 turn to allow fluid and air to escape. Close nipple before the assistant releases the lever/pedal. Repeat until fluid running through tubing is clear and free of bubbles.
  • If using a vacuum bleeder, attach and draw fluid until no air bubbles appear, then close nipple and remove tool.
  • Wipe any spilled fluid immediately; brake fluid can damage paint and plastic.

4. Flushing entire line

  • Continue bleeding each caliper in sequence until fresh fluid appears and no bubbles are visible. Periodically top off the master reservoir so it never runs low or draws air.
  • If lines are very old and contaminated, consider multiple reservoir refills and bleeding passes until fluid clarity is consistent.

5. Final checks

  • Once all calipers are bled and reservoir is topped to the correct level, tighten bleed nipples to spec snugness and reinstall caps and diaphragms.
  • Pump the brake pedal/lever with ATV on stands until firm pedal feel is achieved. With wheels down, test brakes at low speed in a safe area to confirm performance.
  • Inspect for any leaks at bleed nipples and banjo bolts. Re-torque banjo bolts and replace crush washers if they were removed.
  • Properly dispose of old brake fluid; it is hazardous waste.

Troubleshooting

  • Persistent soft pedal after bleeding: recheck for air entry, inspect master cylinder for internal leaks, and inspect caliper pistons for corrosion or sticking.
  • Brake drag after bleeding: ensure bleed nipples are fully closed, pistons are retracting freely, and there is no line kink.
  • If using DOT fluid different from previous fill, flush completely — mixing incompatible fluids can damage seals and reduce performance.

Maintenance tips & model-specific reminders

  • Service interval: replace brake fluid periodically as recommended by Yamaha or sooner if fluid darkens. Moisture contamination is the main cause of brake-system degradation.
  • Inspect caliper seals, hoses, and banjo fittings for age-related deterioration common on older 2009 models. Replace any brittle hoses or leaking fittings.
  • Because the Grizzly 350 is often used in wet & muddy conditions, inspect for contamination around bleed nipples and keep reservoirs sealed after service.
  • Keep spare crush washers on hand; reusing old crush washers at banjo joints often leads to leaks.

Safety reminders

  • Brake fluid is corrosive to paint and plastics. Protect surfaces and wear gloves/eye protection.
  • Never allow the brake reservoir to run dry. Air in the system will require additional bleeding and may mask issues with master cylinder seals.
  • After service, conduct a low-speed braking test in a safe area before full operation.

Follow these MotoSport-tested steps to restore firm, reliable braking on your 2009 Yamaha Grizzly 350 4X4 IRS. If you encounter internal master cylinder failure, caliper seizure, or persistent leak issues, contact a qualified technician for repair or parts replacement.

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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.