Is A Hydraulic E Brake Illegal? (Simple Explanation)

We all know how important our brakes are when it comes to our vehicles. However, the very fact that the brakes are very important for the safety of the vehicle is the reason why cars have more than one brake system.

The other comes in the form of a parking brake, which is also called the emergency brake or the E brake. But, if you wanted to use a hydraulic E brake, is it actually legal for you to do so?

Are hydraulic E brakes illegal?

Hydraulic E brakes are legal, but they must be functional in the sense that they must fully stop the car and leave it on when the vehicle is parked. There are some hydraulic E brakes that tie into the stock calipers to make sure that the car is fully stopped whenever you leave your parked vehicle.

Rally car parked interior seat
Rally car parked interior seat

The important thing about hydraulic E brakes is that they may vary in terms of design and function.

That means that they may not always be legal because there are some hydraulic E brakes that probably do not function in the same way that a regular parking brake does. This is why you need to make sure that your hydraulic E brakes are capable of fully stopping your vehicle when parked.


What is a hydraulic E brake?

Car hydraulic e-brake mechanism
Car hydraulic e-brake mechanism

One of the most important parts of the entire vehicle is the brake system, which ensures that you can stop your vehicle at will whenever you need to do so. This is one of the most important mechanical and safety features that cars need to have. 

And, of course, you also have brakes that are capable of fully stopping the car whenever you need to park the vehicle. That is because you cannot rely on keeping your brake pedals pressed whenever you leave your car parked. This is where parking brakes or emergency brakes (E brakes) come in.

In most cases, E brakes are often only engaged whenever the person needs to leave the car parked. That is because keeping the E brakes engaged will keep the calipers clamped on the wheels to prevent the car from moving.

This is very important when it comes to parking on a steep incline but is also just as important on a flat surface because there could still be external forces that could move the vehicle.

So, while E brakes are usually used for parking, we now have hydraulic E brakes, which are usually installed for different purposes but still somewhat work in the same way.

But what are hydraulic E brakes?

A hydraulic E brake is simply an emergency brake that makes use of hydraulics whenever you are engaging or disengaging it. Most of the mechanical aspects of hydraulic E brakes are similar to how a usual E brake works, but the difference here is that hydraulic pressure is used to allow the calipers to clamp the wheels. Of course, it is also easier for you to engage a hydraulic E brake because how it requires less effort.

Because hydraulic E brakes are easier to use and are capable of acting faster, they are often used by street drivers for drifting.

Regular handbrakes or parking brakes can still work, but hydraulic E brakes allow the driver to engage the brakes faster because it requires less effort from both the person and the braking mechanism.

Is it illegal to have a hydraulic E brake?

Now, when it comes to your car’s e brakes, one of the things you might be wondering is whether or not it is actually legal to have a hydraulic E brake.

Even though hydraulic E brakes may function in a way that is similar to a usual E brake, some hydraulic E brakes might be more suited for street racing and not for your car’s usual day-to-day functions.

So, is it illegal to have a hydraulic E brake?

No, it is not illegal to have a hydraulic E brake in your car as long as they are actually functional. What we mean by functional is that these brakes actually work as emergency or parking brakes and not merely brakes that you can engage or disengage whenever you are out drifting or street racing. 

In most cases, some brake systems are illegal if they are not operative in the sense that they need to have some constant force or pressure applied to them for them to work properly.

A brake system must be held in the applied position by energy other than fluid pressure, air pressure, or electric energy for it to be legal.

So, in this case, because hydraulic E brakes function through the use of a hydraulics system that relies on liquid pressure to work, it is easy to say that these brakes should be illegal. 

However, the thing you need to know is that plenty of hydraulic E brakes still retain the mechanical linkage to the brake calipers that allow the car to come to a full stop when you engage the hydraulic E brake.

As such, what you need to look at here is if your hydraulic E brakes still have that mechanical link that will allow the brake system to function without having to rely on fluid pressure instead of a mechanical system. So, if the car’s hydraulic E brake is capable of working that way, it should still be legal to use.

Can you lock the hydraulic handbrake?

Not all hydraulic E brakes can be locked because there are systems that are fully operated by hydraulics, while some systems are still very much operational in the sense that they still work like regular parking brakes.

So, if your hydraulic E brake is still tied in with the old brake lines that are mechanically connected to the brake calipers, that means that you can lock a hydraulic handbrake. If not, then your hydraulic E brake is more likely just for the purpose of drifting and street racing. The hydraulic E brake would now be illegal if you do not have any other means to fully stop the vehicle without relying on energy that is not operated by fluid or air pressure.

Can you use a hydraulic E brake as a parking brake?

Your hydraulic E brake can only be used as a parking brake if it can be locked. When we say locked, we mean to say that it should be able to stay locked in place when you leave the vehicle so that the car’s brakes will keep the entire vehicle clamped on the spot.

If your hydraulic E brake cannot be locked, then it cannot be used as a parking brake. This is where its legality may come into question, especially if you do not have another brake system that can lock the vehicle in place.


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