How to Bleed and Replace Brake Fluid on a 2009 Yamaha Grizzly 350 4X4
Shop parts for a 2009 YAMAHA GRIZZLY350 ATV.
This MotoSport-exclusive procedure guides you through a complete brake fluid replacement and bleed on a 2009 Yamaha Grizzly 350 4X4 (MMY). Follow these steps carefully to restore firm lever and pedal feel, avoid contamination, and protect painted surfaces.
What you need
- Fresh DOT 4 brake fluid (use new, unopened bottle)
- Clear plastic tubing sized to bleed nipple
- Brake bleed bottle or clean catch container
- Flat and Phillips screwdrivers
- 10 mm and 12 mm wrench set (bleed nipple and caliper/banjo fittings may vary)
- 10 mm socket and ratchet for master cylinder and caliper bolts
- Torque wrench (for refastening hardware to spec)
- Clean rags and isopropyl alcohol for cleanup
- Disposable gloves and eye protection
- Bike stand or ramps to keep the ATV level and stable
Model notes — 2009 Yamaha Grizzly 350 4X4
- The Grizzly 350 uses hydraulic brakes with separate front (handlebar lever) and rear (foot lever) master cylinders and reservoirs. Each circuit has a bleed nipple accessible at the caliper. There is no ABS on this model.
- Reservoirs are small – don’t let them run dry during bleeding. Running dry draws air into the system and lengthens the process.
- Brake lines on this MMY are routed along the A-arms and swingarm; inspect for chafing, cracks, or soft spots while working. Replace any damaged line before finishing the bleed.
- DOT 4 is recommended for modern Yamaha ATVs. Never mix different brake fluids (DOT 3 with DOT 4 is tolerated but not recommended). Avoid silicone-based fluids entirely.
- Caliper and banjo bolt torque specs vary; refer to your Yamaha shop manual or tighten to manufacturer recommendations. If you don’t have the manual, torque new banjo hardware to a moderate setting and verify for leaks on first ride.
Safety and prep
- Work on a cool vehicle with the engine off. Park on a flat, stable surface and secure the Grizzly on a stand so wheels hang free if possible.
- Cover painted surfaces near reservoirs with rags — brake fluid will damage paint.
- Wear gloves and eye protection. Keep rags and waste container ready for used fluid; dispose per local regulations.
Step-by-step: Replace fluid and bleed
- Clean the master cylinder reservoir caps and surrounding area thoroughly to prevent contamination when opened.
- Remove reservoir caps and diaphragm pads. Siphon out old fluid with a turkey-baster or syringed tool until reservoirs are mostly empty, then top with fresh DOT 4 to just below the fill line.
- Start with the caliper furthest from its master cylinder. For the front lever this is typically the left or right depending on plumbing; for the rear start at the caliper and then re-bleed the master if needed. Attach clear tubing to the bleed nipple and place the other end in a catch bottle partially filled with some fresh fluid to avoid drawing air back in.
- Have an assistant slowly pull the brake lever (or pump the brake pedal) several times and then hold pressure. Open the bleed nipple about one-quarter turn to allow fluid and air to exit into the hose. Close the nipple before the lever/pedal is released. Repeat the pump-hold-open-close cycle until you see clear fluid with no bubbles in the hose.
- Keep the reservoir level topped with fresh fluid throughout the process. Do not let it run dry.
- After the caliper is clear, tighten the bleed nipple to spec (or snugly if you do not have specs) and wipe clean. Repeat for the other caliper(s) in order from farthest to nearest relative to each master cylinder.
- Once all calipers are bled, perform a final bleed at each master cylinder if you still feel sponginess. Some owners find a single-person vacuum or pressure bleeder speeds the job and reduces helper fatigue.
- When bleeding is complete, top reservoirs to the correct level, replace diaphragms and caps, and clean any spilled fluid from surfaces with isopropyl alcohol.
- Cycle levers/pedal several times, verify firm, consistent feel. Check all banjo bolts, bleed nipples and fittings for leaks with the system pressurized.
- Test ride gently at low speed to confirm braking performance before normal use.
Troubleshooting
- Persistent sponginess: re-check for air by repeating the bleed, ensuring the reservoir never ran dry, and inspect lines for leaks or collapsed hoses.
- No fluid flow from bleed nipple: open and clean nipple threads, ensure tubing fits snugly, and verify the caliper piston moves when lever/pedal is applied.
- Brake drag after bleed: check caliper piston movement and sliding pins for corrosion & dirt; clean and lube sliders with appropriate high temp brake grease.
Inspection & maintenance tips
- While you have the brakes apart, inspect pads for wear and replace if pad material is 1.5 mm or less. Check rotor condition for grooves or heat spots.
- Inspect banjo washers for deformation; replace copper or steel crush washers whenever you disturb banjo bolts.
- Record fluid change date and mileage. Brake fluid is hygroscopic; repeat service every 1–2 years depending on use and environment.
- If you find soft lines or swollen hose sections, replace them with OEM or high-quality braided hoses rated for ATV use.
Disposal and final checks
- Dispose of used brake fluid according to local hazardous-waste rules; do not pour down drains.
- After completing the job, re-check all fittings after the first short ride. Torque fasteners to manufacturer specs if available.
These MotoSport-specific instructions keep your 2009 Yamaha Grizzly 350 4X4 stopping strong and safe. If you encounter component damage or uncertain symptoms, stop and consult a certified technician before riding.
Related Shopping Categories
Shop Brake Fluid for a 2009 YAMAHA GRIZZLY350 ATV.
Shop Brake Bleeders for a 2009 YAMAHA GRIZZLY350 ATV.
Shop Brake Pads for a 2009 YAMAHA GRIZZLY350 ATV.
Shop Brake Lines for a 2009 YAMAHA GRIZZLY350 ATV.
Shop Brake Tools for a 2009 YAMAHA GRIZZLY350 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.
