How to Bleed Shimano Hydraulic Mountain Bike Disc Brakes

In my eyes bleeding brakes is like a milestone in bike maintenance. Taking you from a beginner to an intermediate mechanic, with suspension service in the advanced realm. As well as convenience bleeding your brakes can save you lots of money in the long run. Especially if you invest in a large tube of brake fluid.
This tutorial will focus on Shimano hydraulic disk brakes. So, if you have another brand this video won’t be of much use.
First, if you don’t already have one, purchase a Shimano brake bleed kit. This one is about the cheapest I could find, and it shows. The plunger doesn’t fit, and the funnel doesn’t screw on properly. Still, it does work well enough to get the job done.
If your kit doesn’t come with brake fluid make sure to get Shimano mineral oil and not some other fluid. Dot fluid is found on Sram brakes and blue mineral oil is used on Magura brakes. Shimano mineral oil is this reddish pinkish colour.
Before we start there are two types of brake bleeds. A flush and refill or a quick lever bleed. If your brakes haven’t been bled in roughly a year or two a flush and refill will replace all the old fluid. However, if your brakes have recently been bled however are feeling spongy, a lever bleed should be enough to remove all the air in the system. This video will focus on a quick lever bleed as it’s the easiest way to learn the basics of bleeding a hydraulic disk brake.
For a quick lever bleed wipe the brake lever. Rotate the lever to a horizontal angle and adjust the lever position to as far out as possible. Remove the wheel and brake pads replacing the brake pads with the included brake bleed block. You may need to push the pistons back in for the bleed block to fit. It’s best to use something soft for this like a plastic tire lever. If the pads don’t push back in skip this step for now. Unscrew this bolt replacing it with the funnel. Now if you were having trouble with the previous step try to push the pistons back in. Next poor in some brake fluid. Now flick the lever like so. Air bubbles should start to come out. Continue until air stops coming out of the system. Flicking the lever like so creates negative pressure in a way that simply pulling the lever won’t give you. This is a trick I learn a while ago and I surprised how little people know about. You may need to refill the funnel if there was a lot of air in the system. Do not continue flicking the lever if there’s no fluid left in the system. Plug the hole with the plunger and unscrew the funnel. If the colour of the brake oil hasn’t changed the oil could be reused. Screw this bolt back in then wiping the area before putting the pads and wheel back on. Finally, reposition the lever to the rider. Repeat with the other brake.
Hopefully, this tutorial was simple enough to understand. I remember totally ruining my first attempt at bleeding brakes. But like everything in life, it’s all about practice. So that’s it for this week’s video, if you enjoyed it please make sure to do what every other KZbinr tells you to do. Thanks, guys.