How to Adjust an eBike's Hydraulic Brakes

Hydraulic disc brakes do need to be adjusted from time to time on your ebike, most of the time after a new brake install, new brake pad install, or after a bleed. It is not as intensive as a mechanical brake install, as you do not have to worry about making sure the pads are balanced or the brakes have good pull and braking power (this is done during the brake bleed). A hydraulic brake adjustment is more just lining up the caliper so that the brake pads are not rubbing on the brake rotor. If they are rubbing, you will typically hear a sound, ranging from a loud scrap/dragging sound, to a small, periodic “ting” noise.

Here is a video walking through the whole process for a visual

The tools you will need for this will be:

  • 5mm Allen/Hex Key
  • Torque Wrench
  • Bike Stand/Way to Hold up the Ebike

Here is the process below:

  1. Loosen the 2 bolts attaching the brake caliper to the frame using the 5mm Allen/Hex key. Do not fully remove them, just loosen them enough so that the brake caliper can move around.
  2. Spin the wheel while the brake caliper is loose, and then grab the brake lever, locking the wheel in place. Repeat this a couple of times.
  3. On the final spin, instead of releasing the brake lever, hold it in place and then tighten down the 2 bolts with your 5mm Allen/Hex key. Finish tightening them to a torque rating of 6-8 nm.

If all goes well, with the self centering pistons, the brake should be centered on the rotor. If you hear it rub, but only at a certain spot on the rotors rotation, then your rotor needs to be trued. Please refer to the Rotor Truing section of this guide.

If this did not center the rotor properly and it is rubbing on one or both sides of the rotor, follow the below directions:

  1. Look directly at the brake caliper from the front so you can see the rotor in between the brake pads. You may need a flashlight to help illuminate the space between them.
  2. Look to see which side the rotor is touching/is closest to the brake pad. Take note of that side.
  3. Loosen just the top bolt securing the caliper and gently push the caliper from the top section the opposite direction from where it was touching. Look into the caliper and check to see if the rotor is centered between the brake pads on the upper section. If so, tighten the top bolt.
  4. Repeat this process for the lower bolt.

If all is done well, the rotor should be centered in between the brake pads. Give the wheel a spin to see if it is dragging on either side of the brake pads. It may take a few times to get it perfectly centered and can take some patience.

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