Electric brake boost.

[flyboyx]

I read an article recently about car manufacturers beginning to use 12v to power the brake booster. this got me thinking, so I started a google search and found that the Lexus RX-450h has been using electric brake boost since around 2010. a little more searching and I found several of them for sale on eBay. the going price for a unit here in the USA was around $100-150.00.

a few weeks ago, I purchased a unit for 40.00 shipped. I figured for that price, I would be happy to take a chance on it.

here are a couple pictures of what arrived in the mail.





there are a lot of potential advantages here. very compact size being the most obvious. it looks like it could be mounted anywhere.

so...there are two hydraulic output ports. the one at the end of the master cylinder probably goes to rear brake line. the one at the servo unit on the bottom probably goes to the front.

the electrical connector only has two terminals. I don't know yet if this unit needs some sort of electronic control module or if you can just apply 12v switched power to those two terminals. it would be difficult to believe it could be that simple, but I guess you never know.......

this project is going to need some research to see if its viable, but I wanted to post it here in the event any of you would like to explore the viability.

in looking at the unit, it appears the servo could be used with any master cylinder even a bmw unit. I wonder if you could use two of them to power both the front and back?

[jpod999]

Very cool, I’m going to be watching this one.

[vtechnik]

Very cool, in for updates

[AlainH]

The servo can only be used with a master cylinder that has an input port for the pressure. The two wires are all you need to build pressure, yes, but... they should be fed through a relay which turns off power to the servo when a certain pressure is reached. You are missing every safety feature these systems have, unless this unit is way more advanced then anything I've worked with.

Also, the brake fluid reservoir you need to use has to be way bigger then what you're used to, because electric brake systems like this damage the fluid very fast (to a rate where with a small reservoir, you'd be replacing the fluid every three months.

Just my experience...

[varg]

Correct me if I'm wrong, but I don't believe that little unit is the brake booster. It's far too small to be a boost pump and as far as I know an in-line boost pump is not a reliable way of boosting hydraulic brakes. I think that part has something to do with fluid control so that the regenerative braking system can operate when the pedal is pressed instead of applying full pressure to the brakes. I have seen electric brake boosters before and they are not compact either, as you'd expect from a robust electromechanical device.

Edit:
I've found this: http://techinfo.honda.com/rjanisis/p...enu_Print.html which confirms my initial thought.

[flyboyx]

That’s an interesting read. Thank you for posting that. Still could be viable but obviously will need more components.

[TobyB]

Holy hell, just another reason to avoid hybrids! That 'brake system' is terrifying...

stroke sensor, indeed...

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