How to Bleed and Replace Brake Fluid on a 1987 Kawasaki Bayou 300 2X4
Shop parts for a 1987 Kawasaki Bayou 300 2X4 ATV.
This MotoSport guide covers step-by-step bleeding and replacing the brake fluid on a 1987 Kawasaki Bayou 300 2X4, plus model-specific notes owners should know. Work in a well-ventilated area on a level surface. Use protective gloves and eye protection; brake fluid is corrosive to paint and plastics.
What you need
- DOT 3 or DOT 4 brake fluid (use fluid meeting OEM specs)
- Clear plastic tubing that fits bleed nipples
- Catch bottle (transparent) with some old fluid or a one-way valve cap
- Turkey baster, fluid syringe, or small siphon
- 10mm or 12mm wrench (check nipple size) and appropriate open-end wrench for banjo bolts
- New crush washers for banjo bolts (if loosening lines)
- Clean rags, brake-clean spray, small wire brush
- Torque wrench (for reassembly) and basic hand tools
Model-specific notes for the 1987 Bayou 300 2X4
- The Bayou 300 uses a simple hydraulic front and/or rear brake system depending on setup; the master cylinder reservoir is small and located near the handlebars. Because the reservoir is compact, keep it topped during bleeding to avoid introducing air.
- Brake lines on this vintage ATV can be brittle or internally collapsed from age; inspect lines for cracking, swelling, or seepage. Replace any suspect lines before bleeding.
- Banjo bolt fittings and crush washers are inexpensive and often corroded on older machines—replace crush washers anytime you open a hydraulic connection.
- Some 1980s Bayou models use drum-style rear brakes or simple single-piston calipers up front. Identify whether you have a caliper or drum bleed nipple and adapt the tools accordingly.
Preparation
- Park ATV on center-stand or securely support so wheels are off the ground if possible.
- Clean around the master cylinder reservoir cap and bleed nipples to prevent contamination.
- Remove reservoir cap and diaphragm; cover surrounding paint with rags to protect from spills.
- Siphon as much old fluid out of the reservoir as possible with a turkey baster or syringe.
Fluid replacement and bleeding recommended sequence
Bleed the system from the wheel farthest from the master cylinder first, then to the closest. For Bayou 300 2X4 common sequences: rear brake (if separate) then front, or passenger-side wheel then driver-side for multi-wheel setups. If only two bleed nipples exist, determine far/near visually.
- Top reservoir with fresh DOT 3 or DOT 4 fluid to the recommended level; do not overfill.
- Attach clear tubing to the bleed nipple and place the other end into your catch bottle partially filled with old fluid to prevent air backflow.
- Have an assistant slowly pump the brake pedal or lever several times and hold it down. While held, open the bleed nipple one quarter to half turn with the wrench to allow fluid and air to escape. Tighten nipple while lever/pedal still depressed. Release lever/pedal. Repeat until the expelled fluid runs clean and bubble-free. Keep an eye on reservoir level and top as needed.
- Repeat the process for the next bleed nipple in sequence. Always close the nipple before releasing the lever/pedal and keep the reservoir capped when done with each station. Never let the reservoir run dry.
- After all circuits are bled, ensure the master cylinder top is clean and secure the cap and diaphragm. Pump the lever/pedal to check for firm feel. If spongy, repeat bleeding until firm.
- Check all fittings for leaks and torque banjo bolts to appropriate spec for Kawasaki small-bore fittings (tighten snugly; if you have a shop manual follow specified torque). Replace crush washers if any line was loosened.
Flushing an old, discolored system
If fluid is dark or contaminated, perform a full reservoir refill/bleed: siphon old fluid, add fresh fluid, then bleed each line until new fluid runs clear. For stubborn contamination, multiple flush-and-bleed cycles may be required.
Post-service checks
- Verify brake lever/pedal travel and firmness at normal operating temperature after a short test ride.
- Inspect lines, fittings, calipers, and drums for leaks.
- Dispose of used brake fluid per local hazardous-waste rules. Do not pour on ground or into storm drains.
Common issues & maintenance tips for Bayou 300 owners
- Rubber seals and hoses age out before metal components on these vintage ATVs. Replace hoses and caliper seals if you find leaks or degraded performance.
- If brakes grab or stick after bleeding, check caliper slide pins, pistons, and drum hardware for corrosion; clean and lubricate with brake-approved grease where appropriate.
- If the master cylinder has internal damage or the lever feels soft despite repeated bleeding, the master cylinder may need rebuild or replacement; use OEM-style rebuild kits.
- Keep a small bottle of compatible brake fluid on hand for top-ups during long rides; the Bayou's small reservoir can lose fluid level quickly if you have a leak.
Safety reminders
- Do not mix DOT 5 silicone fluid with DOT 3/4 systems; use only compatible fluids.
- Brake fluid damages painted surfaces—wipe spills immediately and rinse with water.
- Test brakes in a safe area at low speed before returning to regular use.
Following these steps will give your 1987 Kawasaki Bayou 300 2X4 reliable braking performance. For parts, tools, and OEM-fit components specific to this model, remember to visit our parts page above to ensure proper fitment and longevity.
Related Shopping Categories
Shop Brake Fluid for a 1987 Kawasaki Bayou 300 2X4 ATV.
Shop Brake Bleeders for a 1987 Kawasaki Bayou 300 2X4 ATV.
Shop Brake Pads for a 1987 Kawasaki Bayou 300 2X4 ATV.
Shop Brake Lines for a 1987 Kawasaki Bayou 300 2X4 ATV.
Shop Brake Tools for a 1987 Kawasaki Bayou 300 2X4 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.
