How to Bleed & Replace Brake Fluid on a 2018 Textron Alterra 90

Shop parts for a 2018 Textron Alterra 90 ATV.

This proprietary MotoSport guide walks you through safely flushing and bleeding the brake system on a 2018 Textron Alterra 90 ATV. Follow each step carefully — the Alterra 90 is a compact youth machine with small reservoirs and short bleed lines, so attention to detail matters.

What you need

  • Brake fluid specified by the owner’s manual (check the cap or manual; most small ATVs accept DOT 3 or DOT 4 — follow Textron recommendation)
  • Clear plastic tubing sized to fit bleed nipple snugly
  • Clean catch bottle partially filled with fresh brake fluid
  • Wrenches for bleed nipple (typically 8mm or 10mm)
  • Turkey baster or fluid syringe
  • Brake cleaner, rags, nitrile gloves, safety glasses
  • Jack or stands to lift wheels if needed

Model notes specific to the Alterra 90

  • The brake fluid reservoir is small and mounted near the handlebar master cylinder; it’s easy to run low quickly during bleeding — keep it topped up to prevent air introduction.
  • Front brakes use small hydraulic calipers with accessible bleed nipples; the rear brake may be hydraulic or mechanical depending on production batch — confirm by visual inspection. If mechanical drum or cable rear brake is fitted, no rear hydraulic bleeding will be needed.
  • Use only fresh, unopened brake fluid and avoid spilling on painted or plastic surfaces; the Alterra 90 has plastics that can be damaged by fluid.

Preparation

  1. Park ATV on a level surface, engine off, key out. Secure with parking brake if equipped and block wheels.
  2. Clean around the master cylinder reservoir cap to prevent contamination. Remove cap and diaphragm; use a clean rag to expose fluid level.
  3. Confirm fluid spec on cap/manual. Fill reservoir to the maximum line with fresh fluid.
  4. Locate bleed nipple(s) on the caliper(s). Fit clear tubing over the nipple and route into catch bottle containing some fresh fluid to prevent air re-entry.

Basic pressure bleeding (recommended for solo work)

  1. Have an assistant squeeze the brake lever/pedal gently to build pressure, then hold it.
  2. Open the bleed nipple a quarter to half turn; fluid and air will flow into the tubing. Close nipple before assistant releases the lever/pedal. Repeat until no air bubbles appear and fluid runs clear. Keep reservoir top-off between cycles.
  3. Perform front calipers one side at a time, starting with the caliper farthest from the reservoir if the system has multiple lines.
  4. If rear brake is hydraulic, bleed it last. If the rear is a cable or drum, inspect and adjust cable instead of bleeding.
  5. After bleeding, tighten bleed nipples securely, clean up any spilled fluid, and reinstall reservoir diaphragm & cap.

Alternative vacuum or syringe bleeding

If you have a hand-held vacuum bleeder, attach it to the bleed nipple and draw fluid until clear without air. A syringe can be used at the master cylinder to push fresh fluid through the lines into the calipers while bleed nipples are open — always ensure fluid is flowing out into the catch bottle and reservoir never runs low.

Flush & full fluid replacement

  1. To fully replace old fluid, repeatedly draw fresh fluid into the system by adding new fluid to the reservoir and bleeding until the expelled fluid is the new clear fluid color.
  2. Dispose of used brake fluid responsibly — do not reuse or pour down drains.

Final checks

  • Confirm firm, consistent lever and pedal feel with no sponginess. If spongy, repeat bleeding until resolved.
  • Check for leaks at fittings, lines, calipers, and master cylinder. Tighten or replace components if needed.
  • Wipe any residual fluid from paint and plastics immediately; brake fluid damages finishes.
  • Test brake operation at low speed in a safe area before returning to normal riding.

Maintenance tips specific to this ATV

  • Because the Alterra 90 is often used by new riders, check brakes more frequently — inspect fluid level and lever feel before each ride.
  • Store the ATV indoors or covered when possible; moisture contamination shortens brake-fluid life on small reservoirs.
  • When replacing parts, use replacement items that match Textron specs; incorrect calipers, hoses, or fittings can introduce air or change braking performance.

Related Shopping Categories

Shop Brake Fluid for a 2018 Textron Alterra 90 ATV.

Shop Brake Bleeders for a 2018 Textron Alterra 90 ATV.

Shop Brake Pads for a 2018 Textron Alterra 90 ATV.

Shop Brake Lines for a 2018 Textron Alterra 90 ATV.

Shop Brake Tools for a 2018 Textron Alterra 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.