Hydro boost brakes

A simple question, or maybe more than a simple question 

are hydro boost brakes legal in light trucks etc in Australia ?

with vacuum brakes, you need to gave a vacuum reserve tank that allows a certain amount of brake applications (think maybe 4, maybe more) before the vacuum is depleted that the braking efficiency is affected 

Air brakes on trucks are the same, must have a certain volume of reserve air
I guess this rule doesn't apply to cars as the moment the cars not running you have lost vacuum and the have no vacuum tank like a truck

so getting back to hydroboost, these run off the power steering and have a accumulator,  Yanks seem to love their hydroboost and fit it to every thing as after market fix all

are these legal in Australia for trucks, I would imagine cars have them already

well I did some googling and found this on light vehicles, no mention of hydrboost yet

however it does mention that 2 full applications of the brake without the motor running is required 

 

It doesn't even mention hydroboost brakes that I can see

 


Paul

Mrs
gudday m8
Hydo Boost could B a trade name may B they be called Vacuum assisted brakes
our ol Holden has 'Power Brakes' inscribd on the brake pedal
can remember trucks havein rear signs
'Caution Air Brakes'
cya

I think Swishy is right.

With air or pure vacuum once you lose the system you have zero brakes therefore the required engine-off reserve and the introduction of maxi-brakes.

With the "boost" type system all it does is make the pedal pressure less so lost boost just means heavy pedal pressure but still braking (like lost power steering failure). Suppose similar to air/vacuum over hydraulic in some applications but I think some of these lose even the unassisted operation as well.

Maybe an expert can explain more precisely?

Landcruiser and diesel utes most have electric hydraulic boosted system. Hear the pump run as key is on. Not sure how they work.

I think the rules are very different once it becomes a commercial vehicle rather than a ute

Hydroboost requires the engine tp be running, were as full air or vacuum are fail safe

I guess a hybrid version is air over hydraulic and or vacuum over hydraulic

The braking efficiency is greatly reduced if these power assisted brake boosters aren't there

Hence the need for a resivor and a non return valve

All I guess Im wondering is would hydroboost be legal and if so is there anything in the commercial vehicle type of thing on the market with hydroboost in Australia ?


Paul

I guess I'm seeing if we have amy experts on here to advise on this
Maybe in the back ground that have gone down this road

Paul

Most 4x4, utes etc have a vacuum pump integrated on the back of the alternator. 

Yes they do, they seam simple and reliable
Small American diesels have a vacuum

Trying to think what Perkins use, a device that creates the vacuum and it has a proper name but the brain isnt smart enough today

Americans seem to have taken a real dislike to vacuum boosted brakes for some reason that I can't figure, mainly on their bigger/ full size pickup type utes

I'm not sure if I'm the dumb one and missing the obvious because power boosters seam reliable to me

Paul

From watching a few Yanky hot rod and resto shows, as Paul said, they seem to love the Hyroboost system as a replacement for the vacuum boosters normally fitted to older cars. It fits up just as the vacuum one does, ie between the pedal and the master cylinder.
Haven't see where the hyd. pressure pump is fitted, maybe as Paul said, the power steering unit.

My OKA has Hydroboost system. One thing they are noted for is outstanding brakes.

 The Oka has a 4 wheel disc brake hydroboost braking system as standard with front and rear disc/calipers the same. Not bad for an early 90's vehicle and with the hydraulic pump cam/gear driven brakes and power steering are independent of the fan belt. A very efficient and reliable way of doing things.

This is the OKA system except the OKA pump is gear driven so if you lose your fan belt you do not lose your brake and steering assist.