Hydraulic Brakes Not Working (Spongy)Updated 14 days ago

How to Fix a Spongy Hydraulic Brake

Overview

Are your electric scooter’s hydraulic brakes feeling soft or spongy? This guide helps you diagnose and fix the issue so you can ride safely and confidently. You’ll learn the common causes, how to bleed your brakes, and how to check for leaks or worn parts.

Before You Begin

• Allen keys or appropriate tools for your brake system
• Hydraulic brake fluid (check your scooter’s specifications)
• Bleed kit (usually includes tubing and a syringe)
• Clean rags or paper towels
• Gloves and safety glasses

Solution

Step 1: Identify the Problem

1. Squeeze the brake lever. If it feels soft or pulls all the way to the handlebar, your brakes are spongy.

• Check for visible leaks around the brake caliper, lever, or hoses.
• Inspect the brake pads for excessive wear.

💡 Tip: If you see fluid leaking, do not ride the scooter until the issue is fixed.

Step 2: Bleed the Hydraulic Brakes

1. Remove the brake reservoir cover (usually on the brake lever).

• Attach the bleed kit tubing to the bleed nipple on the caliper.
• Fill the syringe with the correct brake fluid.
• Open the bleed nipple slightly.
• Slowly push fluid through the system while gently squeezing the brake lever.
• Watch for air bubbles coming out with the old fluid.
• Once no more bubbles appear, tighten the bleed nipple.
• Top up the reservoir and replace the cover.

⚠️ Note: Use only the brake fluid specified for your scooter (e.g., DOT 4, DOT 5.1, or mineral oil). Mixing fluids can cause damage.

Step 3: Check for Worn or Damaged Parts

1. Inspect the brake hose for cracks or damage.

• Replace worn brake pads if they are thin or uneven.
• Check that all fittings are tight and secure.

💡 Tip: If you find damaged hoses or fittings, replace them before riding.

Troubleshooting

Issue: Brake Still Feels Spongy After Bleeding

Solution: Bleed the brakes again to remove any remaining air. Check all connections for tightness.

Issue: Fluid Leaking from Caliper or Lever

Solution: Tighten fittings or replace damaged seals/hoses. Do not ride until the leak is fixed.

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Still Need Help?

If you’ve followed these steps and your brakes are still spongy, please [contact our support team] with:

• Your scooter model and year
• A description of the issue and what you’ve tried so far