How to Bleed and Replace Brake Fluid on a 2014 Polaris Sportsman 90

Shop parts for a 2014 Polaris Sportsman 90 ATV.

This MotoSport proprietary guide walks you step-by-step through safely replacing and bleeding the brake fluid on a 2014 Polaris Sportsman 90. Follow these instructions carefully to restore firm braking, prevent contamination, and protect brake components.

Safety & prep

  • Work on a cool ATV on a level surface. Use wheel chocks and center stand or jack stands rated for the machine.
  • Wear nitrile gloves and eye protection. Brake fluid is corrosive to paint and plastic – wipe spills immediately.
  • Use the DOT brake fluid specified in your owner's manual (DOT 3 or DOT 4). Never use DOT 5 silicone fluid with DOT 3/4 systems.
  • Have clean, sealed replacement fluid, a clear bleed hose, a catch bottle, a wrench for the bleeder screw (usually 8mm or 10mm), a syringe or turkey baster, and rags.
  • If using a pressure or vacuum bleeder, follow the manufacturer instructions but still observe the manual bleed checks described below.

Model note for the 2014 Sportsman 90

Polaris built the Sportsman 90 as a youth/utility ATV with a simple hydraulic front braking system; some units have mechanical or combined rear brakes depending on trim and region. Before starting, identify whether your unit has hydraulic calipers on both ends or a mechanical rear brake lever/cable. This procedure covers hydraulic systems; if your rear brake is mechanical, you will not bleed it.

Tools & supplies

  • DOT 3 or DOT 4 brake fluid (new, unopened)
  • Clear plastic tubing that fits snugly over bleeder nipple
  • Small catch bottle and clamp or one-way valve on tubing
  • Wrench for bleeder screw
  • Syringe, turkey baster, or fluid transfer pump
  • Rags, gloves, safety glasses

Step 1 – Locate reservoir and inspect system

Find the brake master cylinder reservoir (usually mounted near the handlebars). Clean the cap area thoroughly to prevent dirt entering the reservoir. Remove the cap and rubber diaphragm; set aside on a clean surface. Note fluid color — dark, dirty fluid indicates replacement is required.

Step 2 – Remove old fluid from reservoir

Use a syringe or turkey baster to remove as much old fluid as possible from the reservoir. Do not let the master run dry during bleeding; keep fluid level at least half full during the procedure to avoid introducing air.

Step 3 – Identify bleeding order

Always bleed starting with the caliper farthest from the master cylinder and proceed toward the nearest. On most ATV layouts that means rear then front, or right-side then left-side depending on plumbing. Trace the brake line from the master to determine the correct sequence for your unit.

Step 4 – Attach tubing and prepare catch bottle

Place the clear tubing over the bleeder nipple and clamp the free end into a catch bottle partially filled with a little fresh brake fluid to prevent air backflow. Make sure the tubing fit is snug to avoid air ingress.

Step 5 – Manual two-person bleed method

  1. One person holds the brake lever/pedal steady while the other opens the bleeder. With the lever released, open the bleeder screw about a 1/4 turn and let fluid drip through the tubing until the flow is steady and free of bubbles, then tighten the screw before the lever is released to avoid sucking air back.
  2. Repeat pumping the lever and opening the bleeder until the expelled fluid is clear and bubble-free. Keep the reservoir topped up between cycles to prevent it running dry.
  3. Continue this process for each caliper in the sequence established earlier.

Step 6 – Single-person pump-and-hold method

If alone, pump the brake lever several times then hold it fully applied while you open the bleeder. Close the bleeder before releasing the lever. Repeat until clear fluid flows and no air bubbles appear. Maintain reservoir level throughout.

Step 7 – Final reservoir replacement and inspection

Once all lines are bled and fluid is clear, top the reservoir to the fill mark with fresh fluid, replace the diaphragm and cap, and wipe any spilled fluid from painted or plastic surfaces. Tighten all bleeder screws to a snug torque — avoid over-tightening. Inspect hoses for leaks and fittings for proper seating.

Step 8 – Test and break-in

  • With the ATV still supported, apply the brake firmly several times to confirm a firm lever/pedal feel. If the lever feels spongy, repeat the bleed process.
  • Lower the ATV and perform slow speed tests in a safe area to confirm braking performance before resuming normal riding.

Maintenance tips & model-specific notes

  • Replace brake fluid every 1-2 years or sooner if fluid darkens. Heat and moisture absorption reduce braking performance.
  • Check caliper pins and pad wear on the Sportsman 90 regularly; replace pads that are below recommended thickness to avoid rotor/caliper damage.
  • If your Sportsman 90 has any soft lines or visible cracking, replace them rather than risking a failure. MotoSport recommends replacing age-hardened rubber lines with new OE-spec hoses.
  • Keep brake components free of grease and lubricants. Contaminated pads or rotors require replacement or professional cleaning.
  • Record the date and mileage/hours when you replaced the fluid for future maintenance scheduling.

Troubleshooting

  • Persistent spongy feel: re-bleed, check for leaks, check master cylinder for internal leakage.
  • Brake lever sinks to the bar: inspect master cylinder seals and caliper pistons for internal leakage; rebuild kit may be required.
  • Brake pedal/lever engagement changes with temperature: verify fluid type and condition; boil/contaminated fluid can cause fade — replace fluid and inspect system.

Following this MotoSport procedure will get your 2014 Polaris Sportsman 90's hydraulic brakes back to safe, reliable operation. If you encounter hardware damage, seized caliper pistons, or master cylinder problems, consider a caliper rebuild or replacement with appropriate parts.

Related Shopping Categories

Shop Brake Fluid for a 2014 Polaris Sportsman 90 ATV.

Shop Brake Bleeders for a 2014 Polaris Sportsman 90 ATV.

Shop Brake Pads for a 2014 Polaris Sportsman 90 ATV.

Shop Brake Lines for a 2014 Polaris Sportsman 90 ATV.

Shop Brake Tools for a 2014 Polaris Sportsman 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.