How to Bleed and Replace Brake Fluid on a 2022 Yamaha Grizzly 90
Shop parts for a 2022 Yamaha Grizzly 90 ATV.
This MotoSport guide walks you through a safe, repeatable brake-fluid change and bleed for the 2022 Yamaha Grizzly 90 (MMY). Procedures are written for routine service at home or in the shop. If you are uncomfortable with any step, stop and have a trained technician complete the work.
What you need
- DOT 3 brake fluid (Yamaha specification for this model) — confirm with the owner’s manual before purchase
- Clear vinyl tubing that fits over the brake bleeder nipple
- Small catch container (marked for brake fluid)
- Wrenches: commonly 8mm and 10mm for bleeder & banjo bolts (verify fit)
- Phillips and flat screwdrivers, pliers
- Clean lint-free rags and rubbing alcohol for cleanup
- Disposable gloves and eye protection
- Torque wrench for reassembly (small range, 6-12 Nm typical)
- Brake bleeder bottle or one-person vacuum/pressure bleeder (optional)
Model notes specific to the 2022 Yamaha Grizzly 90
- Brake reservoir location: master cylinder reservoir is at the handlebar under a small cap — remove plastic cover to access.
- The Grizzly 90 is a youth utility ATV with simple hydraulic brakes and no ABS; bleeder nipples are accessible at each caliper.
- Brake line fittings on this model use small banjo bolts with crush washers — always replace crush washers if disturbed or leaking.
- Because the system is small, only a small volume of fluid is required, but do a full flush if fluid is dark or contaminated.
- Keep spilled fluid off painted surfaces and plastics & dispose of used fluid per local hazardous-waste rules.
Precautions
- Work on a level surface and secure the ATV with the engine off and parking brake applied (if applicable).
- Never let the master-reservoir run dry during bleeding — introduction of air will require more work to remove.
- Do not mix DOT brake fluid types. If you find DOT 4 currently in the system, use only DOT 4 for replacement; consult the manual.
Step-by-step: Complete fluid replacement & bleed
1. Prep the machine
- Park on level ground, put the ignition off and remove the key. Secure the ATV on its stand so wheels with brakes are off the ground if possible.
- Remove any plastic panels blocking reservoir or calipers to get clear access.
- Clean around the reservoir cap and caliper bleeder nipples with a rag and alcohol to prevent contamination.
2. Inspect and note current fluid
- Open the master-reservoir cap (loosen screws) and inspect fluid color. Dark or dirty fluid indicates a full flush is advised.
- Record the reservoir fluid type if marked; if not marked, assume DOT 3 unless manual specifies otherwise.
3. Remove old fluid from reservoir
- Siphon or use a turkey-baster to remove as much old fluid from the reservoir as possible. Do not tilt the ATV to drain through calipers — avoid pulling contaminants from caliper pockets into master cylinder.
- Top the reservoir immediately with fresh DOT fluid to the recommended level to prevent air ingress.
4. Set up bleeding hardware
- Place clear tubing over the bleeder nipple at a caliper. The other end should go into your catch container partially filled with fresh fluid to avoid drawing air back in.
- Have a helper sit on the seat to operate the brake lever if you will use the traditional pump-and-hold method, or use a one-person vacuum/pressure bleeder for single-person operation.
5. Bleeding order
- General rule: bleed the caliper farthest from the master cylinder first, then work toward the closest. On the Grizzly 90 this typically means bleed rear first, then front, or right-side then left-side depending on plumbing layout — verify visually which caliper is farthest from the master cylinder and follow that sequence.
6. Pump-and-hold (two-person) method
- Helper pumps the brake lever several times then holds firm pressure.
- With tubing attached, open the bleeder nipple about a quarter-turn with the correct wrench until fluid flows into the tubing. Close the nipple promptly before the helper releases the lever.
- Repeat: pump several times, hold, open nipple to purge bubbles, then close. Keep reservoir topped between cycles.
- Continue until clear fluid with no air bubbles exits the tubing.
7. Vacuum or pressure bleeder (one-person) method
- Attach the vacuum bleeder to the bleeder nipple or the pressure bleeder to the reservoir per the tool instructions.
- Open the bleeder and draw fluid until it runs clear and bubble-free. Keep reservoir topped if using pressure on the system.
8. Repeat for each caliper
- Work in the bleeding order, ensuring each caliper is bled until bubble-free. Finish with the caliper closest to the master cylinder.
9. Final reservoir top-off and checks
- With all calipers bled, top the reservoir to the correct level and reinstall the cap and diaphragm securely.
- Wipe all fittings and paintwork free of fluid. Replace bleeder caps if removed.
- Check for leaks around banjo bolts and bleeders at idle lever pressure.
10. Reassemble & road-test
- Reinstall any plastics removed, torque banjo bolts and fasteners to manufacturer specs where known (small banjo bolts commonly 6-12 Nm — check service manual for exact values).
- With the ATV still supported, apply the brake several times to confirm firm lever feel. Then perform a low-speed controlled test ride to verify braking performance before full use.
Troubleshooting
- Spongy lever after bleeding: re-bleed, making sure reservoir never ran dry and that you followed the correct caliper sequence.
- Persistent air or loss of pressure: inspect lines for leaks, cracked hoses, or a faulty master cylinder.
- Brake drag after bleed: ensure caliper pistons retracted correctly and that pads sit freely; check rotor alignment.
Maintenance tips for Grizzly 90 owners
- Bleed or replace brake fluid every two years or sooner if fluid is dark, whichever comes first.
- Inspect hoses annually for cracking or hardening; youth ATVs can see more wear if used on trails with frequent turning and throttle/brake inputs.
- Keep spare crush washers and bleeder caps in your tool kit for quick on-trail fixes.
Performing a full brake-fluid replacement and bleed on the 2022 Yamaha Grizzly 90 will restore braking performance and safety when done carefully. When in doubt, have MotoSport-recommended service personnel inspect or perform the work.
Related Shopping Categories
Shop Brake Fluid for a 2022 Yamaha Grizzly 90 ATV.
Shop Brake Bleeders for a 2022 Yamaha Grizzly 90 ATV.
Shop Brake Pads for a 2022 Yamaha Grizzly 90 ATV.
Shop Brake Lines for a 2022 Yamaha Grizzly 90 ATV.
Shop Brake Tools for a 2022 Yamaha Grizzly 90 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.