How to Bleed and Replace Brake Fluid on a 2024 Yamaha Grizzly 90
Shop parts for a 2024 YAMAHA GRIZZLY90 ATV.
This MotoSport guide walks you through a safe, reliable brake fluid change and bleed for the 2024 Yamaha Grizzly 90. Follow each step carefully and perform the work in a clean, well-lit area. If you’re not comfortable with brake systems, have a qualified technician do the job.
What you’ll need
- DOT 3 brake fluid (use the Yamaha-specified fluid; do not mix with mineral oil)
- Clear plastic tubing that fits snugly over the caliper bleed nipple
- Clean catch container
- Wrench for bleeder nipple (typically 8mm or 10mm)
- Phillips or flat screwdriver to open the master cylinder cover
- Turkey baster or syringe to remove old fluid from reservoir
- Clean rags, gloves, safety glasses
- Jack or stands to stabilize the ATV (if needed)
Notes specific to the 2024 Yamaha Grizzly 90
- The Grizzly 90 is a youth/light-duty ATV with a compact brake master cylinder and compact calipers. Reservoir capacity is small — plan to add fluid slowly and don’t let the reservoir run dry during bleeding.
- Yamaha specifies a DOT brake fluid type for the braking system. Use the fluid type called out in your owner’s manual (DOT 3 is commonly used on youth ATVs). Never use mineral-oil-based systems fluid.
- Brake lines and fittings on the Grizzly 90 are small and can be damaged by over-tightening. Use correct-size wrenches and snugble torque; hand-tighten the bleeder and finish with a small turn of the wrench.
- Because this ATV often sees mud and water exposure, check the master cylinder cap seal and reservoir boot for cracking when you service the brakes. Replace any degraded seals to prevent contamination.
- Bleed each brake circuit individually (left/right or front/rear as installed) and verify pedal/lever feel before riding. Test in a safe area at low speed after service.
Preparation
- Park on level ground and secure the engine off with the key removed.
- Clean around the master cylinder cap and the caliper bleeder nipple to avoid contamination entering the system.
- Remove the master cylinder cover and diaphragm. Use a turkey baster to extract as much old fluid as possible from the reservoir.
- Top reservoir with fresh DOT-specified fluid to the recommended level. Do not overfill.
- Attach clear tubing to the caliper bleed nipple and place the other end into a catch container partially filled with fresh fluid to prevent air re-entry.
Bleeding procedure – single-bleeder, pressure or manual method
Use the following manual pump method for the Grizzly 90 unless you have a pressure bleeder.
- Have an assistant slowly operate the brake lever or pedal several times and hold it firmly applied.
- With the lever/pedal held, open the caliper bleeder nipple about a quarter-turn until fluid and bubbles flow into the tubing. Close the nipple before the assistant releases the lever/pedal.
- Repeat: pump or move the lever/pedal to bring fresh fluid from the master cylinder, hold, open bleeder, close, release. Keep the reservoir topped up between cycles so it never runs dry.
- Continue until no air bubbles appear in the tubing and the expelled fluid is clear and free of debris.
- Tighten the bleeder nipple snugly, wipe clean, and reinstall any removed components.
- Repeat the process for each brake circuit (front wheel(s) then rear, or per the Grizzly 90 configuration).
Flush & replace entire system (if required)
- If you’re replacing all fluid, repeat bleeding until the reservoir and expelled fluid are clear. Perform multiple top-up & bleed cycles until master cylinder fluid is fresh.
- Dispose of used brake fluid properly; it’s a hazardous material and must not be poured down drains.
Final checks
- Confirm bleeder nipples are tightened and caps (if present) are installed.
- Check master cylinder reservoir level and reinstall cap and diaphragm securely.
- Operate the brake lever/pedal; expect a firm feel. If spongy, repeat bleeding until firm.
- Inspect for leaks around fittings, lines, and calipers. Tighten if necessary.
- Test ride slowly in a controlled area to confirm braking performance before normal use.
Maintenance tips & common issues
- Regularly check the reservoir level and fluid color. Dark or dirty fluid indicates it’s time for replacement.
- Keep a small bottle of Yamaha-specified DOT fluid on hand for top-ups; avoid long-term storage once opened.
- If you encounter persistent air or a soft lever after repeated bleeding, inspect for a leaking master cylinder seal, damaged line, or caliper piston seal that may be drawing air.
- Because the Grizzly 90 is often used by younger riders, perform brake inspections more frequently if the machine sees heavy use or exposure to water/mud.
Perform follow-up inspections of lines, fittings, and reservoir seals after your first few rides post-service. Proper bleeding and fresh fluid ensure reliable stopping power and extend the life of calipers and master components.
Related Shopping Categories
Shop Brake Fluid for a 2024 YAMAHA GRIZZLY90 ATV.
Shop Brake Bleeders for a 2024 YAMAHA GRIZZLY90 ATV.
Shop Brake Pads for a 2024 YAMAHA GRIZZLY90 ATV.
Shop Brake Lines for a 2024 YAMAHA GRIZZLY90 ATV.
Shop Brake Tools for a 2024 YAMAHA GRIZZLY90 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.
