Will we ever do away with Hydraulic Braking Systems?

I know the benefits and drawbacks of air braking systems vs hydraulic braking systems since we discussed it here, and I can’t help but wonder will we ever do away with hydraulic braking systems?

Why could you not have 4 electrically operated calipers at each wheel? They could be controlled by two different sensors at the pedal and have two separate controllers. You could also set them up that if they lose signal or power the brakes would apply similar to air brake systems.

We have had drive by wire throttle systems for years and have had no issues, why not brake by wire?

Are we afraid of brake by wire, or are there reasons not to have such a system?

variable pressure is easier with hydraulics.

why are you so hell bent on changing the way vehicles stop Rick?

hydraulics seem simple and effective to me. very few failures IMO

I hope not. Hydraulic brakes consume absolutely no power from the engine, they’re extremely reliable, they still work if the engine shuts off (albeit with greater force required), and they’re cost-effective to the manufacturers, so I can’t see any reason to change.

I personally would not want a brake system that totally shut down, or that took power from the battery, if the engine stalled.

Keep in mind im not saying that hydraulic brakes are bad or that we should replace them, Im just saying that we now have electric power steering, electric a/c compressors and cars that park themselves, have the auto makers looked into new braking technology?

Keep in mind some Boeing models and Airbus models are Fly-by-wire, and they work fine.

Mechanical and hydro-mechanical flight control systems are relatively heavy and require careful routing of flight control cables through the aircraft by systems of pulleys, cranks, tension cables and hydraulic pipes. Fly By Wire solves all all that.

My Prius has a form of brake by wire, the regenerative braking works via wire and its perfect. I just bought an R/C Car, A Traxxas Summit, it has brake by wire and it works perfectly.

it seems to me that boeings are dropping quite frequently and the pilots are so used to depending on the computer that they let it lead them to their death without question, and don t have the experience to recover control when needed

How well does your brake by wire system work with a dead or no battery? Imagine trying to push your car back out of the garage to jump start it and then have it roll down the driveway and into your neighbor’s living room because you have no brakes.

How well does your brake by wire system work with a dead or no battery? Imagine trying to push your car back out of the garage to jump start it and then have it roll down the driveway and into your neighbor's living room because you have no brakes.

They could be set up like air brakes, no power and the brakes are applied, It would take power to release the brakes.

Again, not saying this is a great idea for the general public, im just suprised automakers have not dabbled in this yet. Or have they?

Imagine trying to push your car out of the garage to jump start it and then having to call a tow truck to dolly your car to the driveway because your brakes are locked up.

There are 15.5 million semi trucks on the road, and they manage. But you have a point.

Don’t get me wrong, I’m all for technological improvement and advancements, but I think we’re still a little ways off from electric brakes. Your Prius still has conventional hydraulic brakes at each wheel, they’re just controlled electronically.

I have no idea if this is true, but I imagine that an electric servo or motor at each wheel with the sufficient clamping force required might be larger or weigh more than a conventional hydraulic brake mechanism. Since brakes are unsprung weight like wheels any weight reduction or increase will have a big impact on handling and economy. I think the heat might also affect the electronics.

Well there a bunch of electric trailer brakes and they work fairly well(wonder why the ice road gang dont use them?)-Kevin

The only near term advancement which might be possible . . . in my opinion

Electric brakes at each corner, as Rick mentioned

But a complete hydraulic brake system in place, as a backup

Let’s assume the electric brakes are somehow more responsive or efficient, and can activate the calipers quicker than brake fluid

Then on the other hand, if you have that hydraulic system as a backup, you’re not really saving any weight in the end

I just don’t see how you could make a 100% electric brake system . . . with no mechanical or hydraulic fail safe backup . . . reliable enough to put in production

Not at this time, in my opinion

The aircraft may be fly by wire, but the control surfaces are still hydraulically actuated. There are two different types of aircraft systems that use fly by wire. The older ones still used a central hydraulic pump and distribution system. The only thing that changed was eliminating the the linkages between the controls and the actuators.

The newer systems use an electrically powered hydraulic pump located at point of use. They are much smaller and eliminate the hydraulic lines that are prone to developing leaks. They work like a hybrid system. If the actuators were electrically powered, they would need large electric motors.

The small electric motors operate a small hydraulic pump that pressurizes a tank called an accumulator. When the control surface needs to be moved, the high pressure hydraulic fluid in the actuator operates a small hydraulic motor and moves the surface.


Great points. Hydraulic calipers are fairly light weight, Especially fords with phenolic pistons and GMs with aluminum calipers.

Hydraulic brakes are universal because nothing works better or can be manufactured cheaper…

Tire traction is what limits braking efficiency, not the brake system…

Why not build cars that walk on legs instead of roll on wheels? The technology certainly exists to make it possible. I suppose it’s the fact that there is nothing really wrong with wheels. Wheels are simple, reliable, efficient, and trouble free.
It’s the same with hydraulic brake systems.

Ok, it has been done, well an electro hydraulic braking system anyway. Google Mercedes Sensotronic Brake Control.

Long story short they ended up discontinuing the system because it just wasn’t worth it.

In a word picture…
The more complicated the plumbing, the easier it is to clog up the pipes.

I’ll stick with hydraulics.

Now, if they really want to upgrade something, how about getting rid of the brushes and slip rings in alternators?

I wouldn’t be surprised if electrical brakes start being used by the car manufacturers, instead of hydraulics. It’s clear from the discussion above there are indeed some advantages. And replacing brake master cylinders and the aggravating annoyance of somehow bleeding the system and wondering if you got all the air out and the business with the anti-lock system getting in the way and being near impossible to diagnose, with electronically controlled electric brake, it seems like that stuff could all be done away with.