hydraulic handbrakes......good read for those into motorsport! ;)

[IN 05 NT]

hey guys,

been looking into hydraulic handbrake units, they dont look hard to do,

but how do you tap into the brake lines?, do you une a T or Y piece or something?

and how do you bleed them without a reservior?

also aparently illegal in nsw, you must have the mechanical h/b hooked up aswell, i like this set up below....

heres a few pics ive pulled off sites,

home done job, (looks good as it retains both, mechanical and hyd,



this is the typical pull up type....aftermarket one



and the the newer, push down lever type.....



the link:
http://http://www.rallysportmag.com/...1/article.html

OR.....

the copy paste article......hehehehe,

Like most other sports, in rallying you need the right equipment to gain that edge over the competition. The selection of the right golf club can be instrumental in scoring that coveted hole in one, the choice of the right frame can be the one thing that tips the scales in the favour of a long distance cyclist. So it is with rallying. No matter how good a driver you might be, there is always an advantage to be gained by having equipment that is better than the opposition’s.

Having the right equipment to go faster is not always the only answer, however. If you build your car to go faster then you also have to build into it something that will make it stop quicker, turn in better or make it easier to drive faster. We all know that good brakes are essential if you want to put in good stage times – but leaving your braking to the very last second means that you have to find ways of getting around a corner as neatly as possible without sliding off the road with understeer.
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In this article we are going to be looking at fitting a hydraulic handbrake, and look at some of the best types available. The fitment and use of a hydraulic handbrake is just one aspect of being a successful rally driver – as we said before, having the right equipment. But why is a hydraulic handbrake necessary? And why won’t the existing cable-operated handbrake suffice?

In almost every rally you will come across a situation where you need to turn sharply off a road onto another road or track. If the turn is an acute one it may be possible to negotiate the turn without too much drama if you are travelling relatively slowly. If you enter the corner at speed, the natural tendency of the car will be, at best, to understeer towards the edge of the road with the brakes totally locked up or, at worst, to slide off into the shrubbery, necessitating a bit of backing and filling to get back on the road again. Fit a hydraulic handbrake and your problems will be over.
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The upright version is the latest push-forward design that is simplicity itself to use.

Hydraulic handbrake mechanisms have been around almost as long as hydraulic brake systems, performing an important part of any rally car performance. There have been some hastily bodged-up systems that work reasonably well but two new products on the market have taken the level of professionalism to new heights. Marketed by Seemore Motorsport Equipment (0419 538 707 or [email protected]) to their own design, the new hydraulic handbrakes feature real state-of-the-art design. One is the traditional style with the lever in the normal horizontal position while the other is a new, vertical design which is increasingly being seen on World Rally Cars because of its ease of use. The driver operates this latter one by pushing the vertical lever forward rather than backward, a more natural movement than the traditional lift-up method.

As you can see from our pictures, both units are very well made, are strong, light and good looking. The vertical unit has a shaped lightweight handle with a turned aluminium handpiece for comfortable grip, while the horizontal one is very similar but without the aluminium handle. Mate them to a three quarter-inch master cylinder and you have a neat, efficient handbrake that will work well, look good and be long lasting. The units cost $130 for the traditional type and $170 for the vertical Pro model. New three quarter-inch master cylinders retail for $88.
Fitting a Hydraulic Handbrake:

Before you start ripping out your car’s original equipment mechanical handbrake, take the time to understand that most Australian state regulations require all road-registered vehicles to have some form of mechanical handbrake fitted at all times. The reasoning behind this is that the authorities claim that there is less chance of failure with a mechanical handbrake than a hydraulic one where fluid loss could cause a hydraulic system to fail. So if you should happen to be pulled over by the police and you don’t have a working mechanical handbrake, you could be fined. Something to think about. There are several ways of getting around this problem – you can retain the existing mechanical system and install a hydraulic system beside it, or you can adapt an existing mechanical one to be both hydraulic and mechanical.
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Neat and effective, the Seemore range are well engineered and easy to use.

Let’s look at this latter method first. If you’re building a rally car from scratch or you’re not concerned about drilling extra holes in your car’s transmission tunnel, a side-by-side system is not going to concern you greatly. However, if you’re fitting a hydraulic system to your road car (say for motorkhanas, autocross or the odd rally), then you will want to keep your car’s appearance pretty much standard.

You’ll need a 3/4" master cylinder which you can buy new from Seemore Motorsport or any brake specialist, or you can get a Girling-type master cylinder from a Land Rover which will do the job as well. The one pictured here is from a Toyota commercial. A bracket to hold the master cylinder securely to the floor will need to be fabricated, ensuring that it’s strong enough to withstand the leverage from the handbrake without bending it. You’ll also need to buy or manufacture a small clevis pin fitting that will screw onto the piston rod as well as fitting over the rear of the handbrake lever. Trial-fit everything in position on the tunnel, ensuring that the piston rod is parallel with the piston when it’s operated and that you can get enough travel. Pipe up the master cylinder, bleed the system and you’ll have the luxury of a hydraulic handbrake while retaining your mechanical one, all operated by one lever. Of course you will need to ensure that the hydraulic handbrake comes into operation before the mechanical one does otherwise you will be relying on cables that are prone to stretching to operate the rear brakes. Properly adjusted, this dual handbrake should both satisfy the authorities as well as giving you the luxury of an unobtrusive and good looking hydraulic handbrake.
Piping up

No matter how good your brakes are, they won’t ensure confidence if they’re exposed to damage from rocks, sticks and anything else that the front wheels might throw at them. If you’re really stuck with leaving the brake lines in their original position under the car, try and protect them from damage wherever possible. Half inch heater hose slit down one side is suitable for sliding over brake lines or you could obtain lengths of coiled wire that can be found on other brake lines. Where the brake lines pass through the floor of the car to hook into the master cylinder, always use a rubber grommet to stop the brake line rubbing against metal and to keep dust and water out.
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If you want to retain your mechanical handbrake lever, it's easy to include a hydraulic function as well.

If you’re totally re-routing your brake lines on a rally car, always run the piping inside the cabin where it’s completely away from external damage. Secure it neatly to the floor or transmission tunnel with rubber-insulated "P" clips, use grommets where it passes through the bulkhead and the boot panel, and ensure that the line is not under tension or has been kinked. Make sure that the brake line is properly flared at both ends as well as where it screws into the brake cylinder. Bleed the system, ensuring that every skerrick of air is out of the system, then finally check the tightness of all fittings, and you’re done. Remember, to go fast you’ve also got to be able to stop fast! Pretty soon you’ll be doing handbrake turns as well as the experts.
How to do it

Ignoring 4WD cars, which are a totally unique kettle of fish where handbrake turns are concerned, making a handbrake turn in a front wheel drive or rear wheel drive car is simplicity itself. Let’s take RWD first. Assuming that you want to make a sharp right hand turn, the easiest technique to use when you approach the corner is to disengage the clutch (dip the clutch to the floor) to release drive to the rear wheels, turn the steering wheel smartly to the right (or left, depending on the corner) and at the same time pull the hydraulic handbrake up to lock the rear wheels. The combination of plenty of steering lock and locked-up back wheels will swing the car around, using the front wheels as a pivot point. Once the car is facing the correct direction of exit from the corner, immediately release the handbrake, let the clutch out and get back on the power. Of course you will need to have the car in the right gear to be able to accelerate out of the corner without losing too much time. You can choose to go down through the gears as you enter the corner but it is usually preferable to select the right gear just as you release the handbrake on the exit.

Front wheel drive is a little different in that you want to keep the front wheels under power as long as possible. Entering the corner, again pull the steering wheel to the right or left, but keep the power on (if it’s a fairly open corner or dip the clutch momentarily if it’s a tight corner) and quickly pull the handbrake on so that the back wheels lock. Again the back of the car will pivot on the front wheels and slide until you release it, by which time you should be pointing in the correct direction of exit and powering out of the corner. In fact a handbrake can be constantly used to trim the direction of travel in a front wheel drive car, to combat understeer when the car runs too wide into a corner.

A hydraulic handbrake is one of the most useful tools in a rally car provided it’s set up properly and used sparingly. If your car doesn’t already have one, you should think about fitting one now.

blake

so what are your opinions on them?

[takai]

Firstly you have the two types around the wrong way. The vertical unit is a pull back unit, similar to most WRC cars, while the horizontal unit is a pull up same as your road car (apart from stupid footbrake cars like Avalons and Cefiros).

The master cylinder for the handbrake is connected inline with the rear brake line, and usually requires custom lines to be made up.
If you are serious about getting one then have a chat to Mr1JZ on this forum, as i believe he is organising a group buy of them from Seemore

[Big T]

There's an explanation about it here:

http://www.aeu86.org/forum/viewtopic.php?t=608 right at the bottom of the thread.

These are illegal in NSW though... i researched this option before deciding to do the handbrake properly with internal drums instead. In the rare event of a hydraulic failure, you'll be left with ZERO means of stopping the car with this setup.

Eddie.

[thechuckster]

if your setup the handbrake so it activates the original mechanical rear brakes - as well as drives a slave that inline with the rear hydraulic line - you should pass a roadworthy/safety-inspection as the handbrakes will operate hte rear drums regardless of hydraulic fluid.

if done with the approval of your engineer it shouldn't be a big issue?

[Big T]

I'm sure if you could get an engineer to approve it then it would be ok. I didn't bother asking seeing as a disk T-series uses an integral caliper handbrake and i was trying to put brembos on it. There would've been no mechanical handbrake in my case.

Eddie.

[WDE_BDY]

The reason its illegal (in NZ at least, assume same reason over there but you never can tell) is not for emergency stopping purposes. A hydraulic system is not mechanical, and therefore cannot be relied on to hold pressure for extended periods of time. Park your car at the top of a steep hill with a brick on the foot brake, sit back and see how long before its at the bottom.
In NZ, rally cars get special dispensation to run them, but they also have to carry wheel chocks in the boot to pass the road worth inspection (WoF). My own car will run a hydraulic setup while retaining the mechanical setup as well.

Callum

[IN 05 NT]

oh sweet i'll have to pm mr1jz

i like the first home set up as it retains both the mech and hyd, i have plans for the celica to do alot of motorkhana/khanacross events aswell as track days, and i would like a meh set up incase the fluid boils....

p.s, thanks for the rep points,

blake

[Rinmax]

I have a home made hyd handbrake in my TA22, and when I get a second I'll go take some pics for you. As for hooking it up you can't just put in a "t" connector before and after the handbrake, because when you pull on the handbrake your pressure is sent 50/50 forwards and backwards down the lines. If you use a clutch master with a line in rather than a reservoir then it pulls the fluid from the front half of the line and pressurses the back locking the brakes.
I have only found one bad side effect, and thats when you have the hydralic handbrake and the brake pedal at the same time it will lock up the brakes when you let go of both of them, a few pumps of the pedal and it will unlock. This happens because you can force too much pressure down to the calipers. So when you have it only use the pedal OR the handbrake not both or it will all just jam up.
Other than all that I can't speak highly enough of the hyd handbrake, awesome for flick turns. If you are getting serious about motorkhana then this is a great way to go.

[IN 05 NT]

I have a home made hyd handbrake in my TA22, and when I get a second I'll go take some pics for you. As for hooking it up you can't just put in a "t" connector before and after the handbrake, because when you pull on the handbrake your pressure is sent 50/50 forwards and backwards down the lines. If you use a clutch master with a line in rather than a reservoir then it pulls the fluid from the front half of the line and pressurses the back locking the brakes.

i figured that it would have an effect on the whole system,

so how does the clutch master system work? "line in rather than a resevoir" ?

would you have to use a brake bias valve if you were to avoid the full lock up with your system?

cheers, blake

[Rinmax]

Here are the some pics of my set-up of the handbrake.



and this is what I was trying to say that you need a master cylinder with a line "IN" rather than a reservior like this one.



This set up uses the front half of the rear brake line as its reservoir to draw fluid from and only applies pressure to the back half.
Hope this makes sense to help you set up a hyd handbrake of your own.

[IN 05 NT]

ahhhh...ok i totally get you now!,

what did you rip that cluch master off? and do you still run the mechanixcal aswell? (cant see any cable?)

blake

[Rinmax]

I don't have any mechanical cable as mine is a tarmac rally car so I can get away without having one, I also can't be stuff hooking a cable up as my TA22 has a Corona rear end with disc brakes.
As for what the clutch master is from I'm not to sure, but i have seen these used on trailers so they can have a remote reservoir. Most good clutch and brake places should be able to supply one fairly cheap.

I know mine isn't the ideal set-up but it works for me, and I hope you can get something up and working.

[IN 05 NT]

sweet mate, i pmed mr 1jz

i'm wauting to hear from him, see how much the aftermarket kits are....they are getting,

if they are too dear i'll just make up a setup like yours, and keep the mechanical cable sio it meet roadworthy....as everything else does in the celica!

p.s, one rep point 4 you for the help!, cheers

blake

[Rinmax]

Cheers, always willing to help out fellow racers.

[thechuckster]

fwiw, i've seen an MA61/RA6* handbrake setup just like that in a rally car - but with the hand-brake cable still functioning.

You'll probably want to be able to remove/re-attach the button but that's a minor thing.

you might find it safer (for the brake line) to have all that hard piping inside the cabin until it heads down and out near the diff/trailing arms. As long as the piping is securely fastened you should get thru engineering/scrutineering without trauma. The less there is under the car, the less likely a rock/stick is going to punch a hole or crush it.