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Bike Brake Bleed Kits


A bike brake bleed kit is a set of tools and supplies used to bleed or remove air bubbles from the brake system of a bicycle. The brake system of a bike is a closed system of hoses, callipers, and levers that use brake fluid to transfer pressure from the brake lever to the brake pads. Over time, small air bubbles can get trapped in the system, which can reduce the effectiveness of the brakes and cause a spongy or unresponsive feel when the brake lever is applied.

What’s in a Brake Bleed Kit

A typical bike brake bleed kit includes the following items:

  • Brake fluid: a special type of fluid designed for use in bike brake systems, typically DOT 3 or DOT 4, or Mineral Oil

  • Bleed block: a small block that is inserted into the brake calliper to keep the brake pads apart and prevent the pistons from moving while bleeding the brakes

  • Bleed syringe: a small syringe used to draw brake fluid from the system and inject new fluid into the system

  • Bleed hose: a small hose that connects the bleed syringe to the brake calliper

  • Torx wrenches or Allen keys: to remove the brake calliper or lever

Brake Bleed Procedure

The process of bleeding bike brakes involves removing the brake calliper or lever, attaching the bleed hose to the bleed port, and using the bleed syringe to draw old fluid out of the system and replace it with fresh fluid. The process can be a bit messy and requires some basic mechanical skills, but it is not particularly difficult. It's important to follow the manufacturer's instructions when bleeding the brakes and to use the correct brake fluid for your specific bike. It's also important to check the brake pads, rotor, and the lever's pivot point for any wear or damage; if any of those components need replacement, it's important to do so before bleeding the brakes.

Bleeding the brakes is an important step in maintaining the performance and safety of a bike, and it's recommended to do it periodically, especially if you notice any spongy or unresponsive feel when braking or if you haven't done it in a while. It's also important to note that an adept level of mechanical skills is required to bleed your brakes effectively. If you're not comfortable with the process, it's best to contact your local bike store and book it into a mechanic.