Have you ever squeezed your brake lever and felt like pressing a sponge? That’s not normal. It means air has entered your hydraulic brake system.
Brake fluid is incompressible by design, but air bubbles ruin linear power transmission. To restore that crisp, instant bite, you need to bleed – not just change – your brake fluid.
Bleeding is all about pushing every air bubble out. The golden rule: low-point fill, high-point vent. Keep fluid flowing from the caliper (low) to the reservoir (high), and bubbles will naturally rise and escape.
| Tool | Specification / Fitment | Why “Good Enough” Fails |
|---|---|---|
| Bleeding Syringe (x2) | 50–60mL, Luer lock | standard syringes can’t build steady pressure |
| Brand-specific Bleed Fitting | matches your caliper’s bleed screw thread | wrong threads cause air/fluid leaks |
| Brake Fluid (mineral or DOT) | strictly follow manufacturer’s spec | mixing fluids destroys seals – brake failure |
| Clear Bleed Tubing | 2–3mm ID, PVC | clear = you see bubbles moving out |
| Open-end Wrench | 7mm or 8mm (depends on caliper) | wrong size strips the screw |
| Brake Block / Pad Spreader | matches pad gap | prevents piston pop-out & fluid spills |
Nice-to-have: bent tweezers, isopropyl alcohol, nitrile gloves (DOT fluid is corrosive).
DOT fluid damages paint, carbon fiber, and plastics. Rinse immediately with plenty of water. Avoid eye contact.
Used DOT fluid is hazardous waste. Take it to an auto parts store or recycling center. Never pour it down a drain.
Working on your brakes affects riding safety. Only proceed if you have adequate mechanical skills. Always test braking in a safe, open area.
Now that you understand the “why” and the tools, you’re halfway there. In our next post, we’ll walk you through step-by-step bleeding – until the last bubble is gone.
Your lever will feel brand new again.
