Electric Scooter Hydraulic Brakes [Complete Guide]

Last Updated on May 17, 2023 by Matt

closeup of hydraulic brakes of an electric scooter

I’ve ridden many scooters with different types of brakes, but hydraulic brakes win hands down with their stopping power and reliability.

In this guide, I’ll break down all there is to know about electric scooter hydraulic brakes, including their building blocks, pros and cons, as well as their adjustment and repair procedures.

What are hydraulic brakes?

Hydraulic brakes are a popular type of braking system that stop or slow down a vehicle using liquid pressure. Their components include brake lines, a master cylinder, a caliper, brake pads, and a rotor disc. These brakes are preferred over other types because of their consistent performance and powerful stopping ability. Some of the best hydraulic brake brands include Shimano, NUTT,  Magura, and Formula.

Components of electric scooter hydraulic brakes

electric scooter hydraulic brakes components

Electric scooter hydraulic brakes are made up of several components.

There is a usually master cylinder in the scooter’s handlebars with a piston and reservoir to store hydraulic fluid.

Mineral oils are the standard hydraulic fluid used in these brakes, but some high-end electric scooter models use DOT (Department of Transportation) brake fluid. DOT fluid can handle high temperatures and is only used in more powerful electric scooters.

Next, we have a brake line, a narrow tube that carries hydraulic fluid from the master cylinder to the brake caliper. The caliper usually contains single or multiple pistons that close in on the brake pads when needed.

The final component is a metal rotor disk which is typically attached to the rear wheel’s hub.

Now that you know the components of the system, it’ll be easier to understand how a hydraulic braking system works.

How do electric scooter hydraulic brakes work?

diagram illustrating how electric scooter hydraulic brakes work

When the rider clamps down on the brake lever of the scooter, the piston in the master cylinder pushes fluid through the brake line into the brake caliper.

The pistons in the brake caliper are forced by the pressure from the hydraulic fluid to close in on the brake pads, which then come in contact with the brake rotor disc to increase friction and slow down the scooter to an eventual stop.

Pros of electric scooter hydraulic brakes

The following advantages of hydraulic brakes will help you understand why they are the best type of brakes found in electric scooters today:

  • Hydraulic disc brakes have way better stopping power than other e-scooter brakes because they are more efficient. The force you apply to pull the brake lever on the handlebar is multiplied by the hydraulic system. Due to the increase in pressure, the hydraulic fluid pushes the pistons forward with a force more powerful than the one applied at the lever and stops the scooter.
  • Since the braking system is enclosed inside the electric scooter and isn’t exposed to water or dirt, it doesn’t require frequent maintenance. For the same reason, you don’t have to worry about cleaning the brakes.
  • Hydraulic brakes offer better control because they can brake as fast or as gradually as the rider pleases. This is beneficial in emergency situations when you need to stop your scooter at the last minute.
  • Since hydraulic brakes are lightweight, they don’t add any load to the electric scooter’s motor. This is why you’ll find them in almost all high-performance scooters.
  • Electric scooter hydraulic brakes are easy to operate by pulling the brake lever according to how fast or slow you want to brake. You don’t have to use great force or put in much effort.
  • The hydraulic fluid used in these brakes is incompressible and produces less friction when carried through the brake lines. So, the system is less prone to wear and tear.

Cons of electric scooter hydraulic brakes

The following are the disadvantages of hydraulic brakes. Though the advantages outshine them, they are still important to consider when considering hydraulic brakes.

  • The design of hydraulic brakes is more complex than other brake systems, so maintaining and servicing them can be difficult and expensive. You’ll most likely need to have the mechanic check your electric scooter out because they know their way around the system better.
  • The mineral oil that is used as hydraulic fluid starts thickening under -15°F / -26.11°C while DOT fluid starts turning viscous below -30°F / -34.44°C. This can affect the braking performance of your scooter.
  • Hydraulic brakes are made of high-quality materials and are almost always more expensive than mechanical brakes.
  • Spare parts of an electric scooter hydraulic brake are hard to find and can be quite expensive, so you might have some trouble if you ever need replacements.
  • If your brake lines get damaged, the brake fluid could leak and lead to brake failure.

How do you adjust and repair hydraulic brakes on an electric scooter?

Here are some common hydraulic brake issues with ways to adjust or repair them.

Decreased brake lever reach

If completely pulling your brake lever down to the grip of the handlebars is not giving you the stopping power it should, the brake lever’s distance from the handlebar could be the issue.

This can be fixed by using the adjustment knobs located on the brake levers. While some knobs can be adjusted just by twisting them with your fingers, others require tools. To know what tool to use, check out your electric scooter’s or the brake system’s user manual.

Turning the knob right will pull the lever out, and screwing it left will bring it in. To get more stopping power from your brakes, increase the distance between the grip and brake lever and test your scooter to see if the stopping power has improved.

The following video does a great job of showing the adjustment procedure. The person is adjusting the brake lever position on his bike, but the process will also be the same for an electric scooter.

Warped brake disc

If your electric scooter has reduced braking capability and makes scraping noises when applying the brakes, it’s a good idea to check out the brake disc. If your brake disc is bent somewhere, the scraping noise may be coming from the bent portion of the disc scratching on the brake caliper.

Damage to the rotor disc usually occurs when your scooter goes through a nasty fall or collision.

If the bend is minor, you can fix the disc yourself by using a disc rotor truing tool or just a standard wrench. Using your brake caliper as a reference point, spin the rear wheel of your scooter to find the bend and mark the position with a marker. 

Then spin the wheel to a position that gives you a clear view and access to the bent portion. Using the truing tool, bend the disc back into shape.

I haven’t done this on any of the scooters I’ve tried, but I’ve seen people do it on other scooters. The adjustment may take some time, effort, and precision, but it usually works great. I recommend the following video as a reference.

If the disc is too damaged to fix with a truing tool, you’ll probably need to get it replaced.

Loose brakes

If your electric scooter hydraulic brakes are loose, the rear tire will not completely stop when you pull on the brake lever. Another sign of loose brakes is that you’ll hear an unusual noise whenever you apply them, indicating that the brake pads are not properly making contact with the rotor disc.

To fix this, check the disc on the rear wheel first to ensure it isn’t bent. Give the wheel a spin and notice if the spinning disc’s edge aligns with the caliper edge in a straight line. If it does, that means the disc isn’t the problem, and you can move on to the next step.

To adjust the contact point between the brake pad and rotor disc, get a ratchet, an extension, and a suitable Allen key. Undo the arm on the caliper by rotating the screw anticlockwise and adjusting the arm in a way that the wheel spins freely, but the brakes aren’t slack either. Tighten back the screw to retain the adjustment but be careful not to overtighten it.

Spin the rear wheel while pulling the brake lever to check if the issue has been fixed. Unlike what you saw before the adjustment, you’ll notice that the wheel will completely stop.

Check out the video below for a better idea of how this adjustment procedure works.


Air bubbles in the hydraulic fluid

person performing hydraulic brake bleeding on an electric scooter

Air bubbles in the hydraulic fluid can cause it to become compressible, compromising the braking ability of your scooter. A way to solve this issue is to bleed your hydraulic brakes. The procedure is a bit advanced, so I’d recommend doing it yourself only if you have the right knowledge and skill. 

A friend of mine tried doing it himself, but it was a disaster. He ended up taking the scooter to the mechanic anyway to get the problem fixed.

Still, if you want to give it a try, here’s a video explaining the steps.

In the video, the guy started by unscrewing the bleed cap on the handlebar using an Allen key and connected an empty lever syringe. You can get these syringes separately or buy them as part of a hydraulic bleeding kit.

He then uninstalled the caliper and used a brake block to pause the working mechanism of the brakes. Next, he unscrewed the cap on the caliper that sealed in the hydraulic fluid and used a syringe to push in some mineral oil.

Then he installed the caliper back after removing the brake block and moved back to the first syringe. Pulling on the brake lever multiple times, he removed all air bubbles and then detached the syringe.

Finally, he screwed the bleeding cap back on, completing the procedure.

Worn-out or damaged parts

If any parts of your electric scooter’s hydraulic brake systems are worn out or damaged, your best bet would be to have them replaced by a professional technician. Brakes are an electric scooter’s most important safety aspect, so you don’t want to risk your safety by taking on an extensive repair or replacement job. 

So, while adjusting some minor features isn’t a big deal, extensive repair and replacement should be done by someone who understands the complex brake system better. 

Best electric scooters with hydraulic brakes

Based on my experience and testing of many different scooters, these are the best ones that have hydraulic brakes:

Best hydraulic brakes for electric scooters

The hydraulic brakes of your electric scooter should always be ones manufactured by a reliable brand. These brands use high-quality materials and ensure the brakes undergo rigorous safety testing before being released on the market.

Here are some brands well-known for their excellent performing brakes:

  • Shimano
  • Formula
  • Magura
  • NUTT
  • Tektro

Are hydraulic brakes worth it on an electric scooter?

If you prioritize safety over everything else, then installing hydraulic breaks on your scooter will be well worth it. They are the highest-quality type of brakes, have more stopping power than any other type of electric scooter brakes, and are perfect for emergency braking. 

You can count on them to be consistent on all terrains and most weather conditions. An additional benefit is that a lot of the common issues that occur with these brakes, you can probably fix them yourself by just adjusting a few screws.

The only downsides are that hydraulic brakes can be a bit expensive, and their spare parts can be hard to find. Also, any kind of major maintenance or replacement may have to be done by a professional mechanic. So, as long as you don’t mind investing in these brakes, they’re a great choice for your electric scooter.

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Matt standing next to his Xiaomi M365 Pro electric scooter and holding an electric scooter helmet
My name is Matt Trajkovski. I love electric scooters, and electric vehicles in general. I like doing a lot of testing, reviewing, and research on various electric scooter models and brands, looking for great value and performance, both through data and experience. All of the content published on this blog goes through a rigorous review and editorial process, and our product reviews not only include the hands-on experience of our own team members, but the experience of our audience members as well. My goal is to provide you with the best information about electric scooters possible. You can see all of my posts in my articles archive.

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