If you are finding that you are needing to apply more pressure on your brake levers to find the same amount of braking force as before, it’s likely that you have air in your braking system. All hydraulic brake systems need to be bled (also known as purged) for a couple of reasons. You may need to remove air bubbles from the brake system, or when you are replacing the brake fluid with new brake fluid.
These Shimano Bleed Kits are designed to make bleeding your Shimano Brakes easy. You can buy them online and if you have any further questions, please get in touch.