How to Bleed Hydraulic Bike Brakes
Quick Answer
Attach a bleed kit, open the bleed port, pump the brake lever, and close the port to remove air bubbles.
How to troubleshoot How to Bleed Hydraulic Bike Brakes
Spongy brakes indicate air in the hydraulic system. This guide covers bleeding mineral oil or DOT fluid brakes.
Step-by-Step Fix
- Attach the bleed kit to the brake calliper and lever.
- Open the bleed port on the lever and fill the syringe with brake fluid.
- Pump the brake lever to push fluid through the system.
- Watch for air bubbles in the syringe at the calliper end.
- Close the bleed port and remove the bleed kit.
- Test the brake lever - it should be firm with no sponginess.
Common Error Codes
| Code | Meaning | Resolution |
|---|---|---|
| Brakes still spongy | Air still in the system | Repeat the bleeding process. |
| Brake fluid leaks | Loose connections | Tighten all bleed ports and connections. |
Frequently Asked Questions
How often should I bleed my brakes?
Every 6-12 months, or when the brakes feel spongy.
Can I use mineral oil in DOT brakes?
No, use the specified fluid for your brake system.